CN108657159B

CN108657159B - Hybrid electric vehicle, power system and power generation control method thereof

Info

Publication number: CN108657159B
Application number: CN201710210236.1A
Authority: CN
Inventors: 谢武; 陈新立; 刘学礼; 李加林
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2017-03-31
Filing date: 2017-03-31
Publication date: 2020-09-15
Anticipated expiration: 2037-03-31
Also published as: WO2018177356A1; CN108657159A

Abstract

The invention discloses a hybrid electric vehicle, a power system and a power generation control method thereof, wherein the power system comprises: the engine outputs power to wheels of the hybrid electric vehicle through the clutch; the power motor is used for outputting driving force to wheels of the hybrid electric vehicle; a power battery for supplying power to the power motor; a DC-DC converter; a low-voltage battery connected to the DC-DC converter; the auxiliary motor is connected with the engine, the auxiliary motor is respectively connected with the power motor, the DC-DC converter and the power battery, and the auxiliary motor is driven by the engine to generate electricity; and the control module is used for controlling the auxiliary motor to enter a generated power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable the engine to operate in a preset optimal economic area, wherein after the auxiliary motor enters the generated power regulation mode, the control module is also used for regulating the generated power of the auxiliary motor according to the SOC value of the low-voltage storage battery, so that the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained.

Description

Hybrid electric vehicle, power system and power generation control method thereof

Technical Field

The present invention relates to the field of automotive technologies, and in particular, to a power system of a hybrid vehicle, a power generation control method of a hybrid vehicle, and a computer-readable storage medium.

Background

With the continuous consumption of energy, the development and utilization of new energy vehicles have gradually become a trend. The hybrid vehicle is driven by an engine and/or a motor as one of new energy vehicles.

However, in the related art, the motor generator of the hybrid vehicle serves as a driving motor and also serves as a generator, so that the rotation speed of the motor generator is low during low-speed driving, and the generated power and the generated efficiency of the motor generator are also very low, so that the power demand for low-speed driving cannot be met, and it is relatively difficult for the entire vehicle to maintain low-speed electrical balance.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, a first object of the present invention is to provide a power system of a hybrid vehicle, which can maintain the low-speed electrical balance and the low-speed ride comfort of the vehicle.

A second object of the present invention is to provide a hybrid vehicle. A third object of the present invention is to provide a power generation control method for a hybrid vehicle. A fourth object of the invention is to propose a computer-readable storage medium.

In order to achieve the above object, a power system of a hybrid vehicle according to an embodiment of a first aspect of the present invention includes: an engine that outputs power to wheels of the hybrid vehicle through a clutch; a power motor for outputting a driving force to wheels of the hybrid vehicle; the power battery is used for supplying power to the power motor; a DC-DC converter; the low-voltage storage battery is connected with the DC-DC converter; the auxiliary motor is connected with the engine, the auxiliary motor is respectively connected with the power motor, the DC-DC converter and the power battery, and the auxiliary motor is driven by the engine to generate electricity; and the control module is used for acquiring the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle, and controlling the secondary motor to enter a power generation power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable the engine to operate in a preset optimal economic area, wherein after the secondary motor enters the power generation power regulation mode, the control module is also used for regulating the power generation power of the secondary motor according to the SOC value of the low-voltage storage battery.

According to the power system of the hybrid electric vehicle provided by the embodiment of the invention, the engine outputs power to the wheels of the hybrid electric vehicle through the clutch, the power motor outputs driving force to the wheels of the hybrid electric vehicle, the power battery supplies power to the power motor, the secondary motor realizes at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter when driven by the engine to generate power, the control module acquires the SOC value of the power battery, the SOC value of the low-voltage storage battery and the vehicle speed of the hybrid electric vehicle, controls the secondary motor to enter a generated power regulation mode according to the SOC value of the power battery and the vehicle speed of the hybrid electric vehicle so as to enable the engine to run in a preset optimal economic area, and regulates the generated power of the secondary motor according to the SOC value of the low-voltage storage battery after the secondary motor enters the generated power regulation mode, therefore, the low-speed electric balance and the low-speed ride comfort of the whole vehicle can be maintained, and the performance of the whole vehicle is improved.

In order to achieve the above object, a hybrid vehicle according to a second aspect of the present invention includes the power system of the hybrid vehicle.

According to the hybrid electric vehicle provided by the embodiment of the invention, the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained, and the performance of the whole vehicle is improved.

In order to achieve the above object, a power generation control method for a hybrid vehicle according to a third aspect of the present invention includes: acquiring an SOC value of a power battery of the hybrid electric vehicle, a vehicle speed of the hybrid electric vehicle and an SOC value of a low-voltage storage battery of the hybrid electric vehicle; controlling an auxiliary motor of the hybrid electric vehicle to enter a generated power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable an engine of the hybrid electric vehicle to operate in a preset optimal economic area, wherein the auxiliary motor is driven by the engine to generate power; and when the auxiliary motor enters a generated power regulation mode, regulating the generated power of the auxiliary motor according to the SOC value of the low-voltage storage battery.

According to the power generation control method of the hybrid electric vehicle provided by the embodiment of the invention, the SOC value of the power battery, the SOC value of the low-voltage storage battery and the vehicle speed of the hybrid electric vehicle are obtained, the secondary motor is controlled to enter the power generation regulation mode according to the SOC value of the power battery and the vehicle speed of the hybrid electric vehicle, so that the engine runs in the preset optimal economic area, and after the secondary motor enters the power generation regulation mode, the power generation power of the secondary motor is regulated according to the SOC value of the low-voltage storage battery, so that the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained, and the performance of the whole vehicle is improved.

In order to achieve the above object, a fourth aspect of the present invention provides a computer-readable storage medium having instructions stored therein, which when executed, the hybrid vehicle executes any one of the power generation control methods.

Drawings

FIG. 1 is a block schematic diagram of a powertrain of a hybrid vehicle according to an embodiment of the present invention;

FIG. 2a is a schematic structural diagram of a powertrain system of a hybrid vehicle according to an embodiment of the present invention;

FIG. 2b is a schematic structural diagram of a powertrain system of a hybrid vehicle according to another embodiment of the present invention;

FIG. 3 is a block schematic diagram of a powertrain of a hybrid vehicle according to one embodiment of the present invention;

FIG. 4 is a schematic diagram of a transmission configuration between an engine and corresponding wheels according to one embodiment of the present invention;

FIG. 5 is a schematic diagram of a transmission configuration between an engine and corresponding wheels according to another embodiment of the present invention;

FIG. 6 is a block schematic diagram of a powertrain of a hybrid vehicle according to another embodiment of the present invention;

FIG. 7 is a graphical representation of engine characteristics according to one embodiment of the present disclosure;

FIG. 8 is a block schematic diagram of a hybrid vehicle according to an embodiment of the present invention;

fig. 9 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention; and

fig. 10 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

Referring to fig. 1 to 5, a power system of a hybrid vehicle according to an embodiment of an aspect of the present invention is described, which provides sufficient power and electric energy for normal driving of the hybrid vehicle.

Fig. 1 is a block schematic diagram of a powertrain of a hybrid vehicle according to an embodiment of the present invention. As shown in fig. 1, the power system of the hybrid vehicle includes: the system comprises an engine 1, a power motor 2, a power battery 3, a DC-DC converter 4 and an auxiliary motor 5.

As shown in fig. 1 to 3 in conjunction, the engine 1 outputs power to the wheels 7 of the hybrid vehicle through the clutch 6; the power motor 2 is used to output driving force to wheels 7 of the hybrid vehicle. That is, the power system of the embodiment of the invention can provide power for the normal running of the hybrid electric vehicle through the engine 1 and/or the power motor 2. In some embodiments of the present invention, the power sources of the power system may be the engine 1 and the power motor 2, that is, either one of the engine 1 and the power motor 2 may output power to the wheels 7 alone, or the engine 1 and the power motor 2 may output power to the wheels 7 at the same time.

The power battery 3 is used for supplying power to the power motor 2; the sub-motor 5 is connected to the engine 1, and for example, the sub-motor 5 may be connected to the engine 1 through a train wheel end of the engine 1. The auxiliary motor 5 is respectively connected with the power motor 2, the DC-DC converter 4 and the power battery 3, and when the auxiliary motor 5 is driven by the engine 1 to generate electricity, at least one of charging the power battery 3, supplying power to the power motor 2 and supplying power to the DC-DC converter 4 is realized. In other words, the engine 1 may drive the sub-motor 5 to generate electric power, and the electric power generated by the sub-motor 5 may be supplied to at least one of the power battery 3, the power motor 2, and the DC-DC converter 4. It should be understood that the engine 1 may drive the sub-motor 5 to generate electricity while outputting power to the wheels 7, or may drive the sub-motor 5 alone to generate electricity.

From this, driving motor 2 and auxiliary motor 5 correspond one-to-one respectively and act as driving motor and generator, because auxiliary motor 5 has higher generating power and generating efficiency during low-speed to can satisfy the power consumption demand that the low-speed traveles, can maintain whole car low-speed electric balance, maintain whole car low-speed ride comfort, promote the dynamic behavior of whole car.

In some embodiments, the secondary electric machine 5 may be a BSG (Belt-driven Starter Generator) electric machine. It should be noted that the auxiliary motor 5 belongs to a high-voltage motor, for example, the generated voltage of the auxiliary motor 5 is equivalent to the voltage of the power battery 3, so that the electric energy generated by the auxiliary motor 5 can directly charge the power battery 3 without voltage conversion, and can also directly supply power to the power motor 2 and/or the DC-DC converter 4. And the auxiliary motor 5 also belongs to a high-efficiency generator, for example, the auxiliary motor 5 is driven to generate electricity under the idling speed of the engine 1, so that the generating efficiency of more than 97 percent can be realized, and the normal generating efficiency is improved.

In addition, in some embodiments of the present invention, the secondary motor 5 may be used for starting the engine 1, that is, the secondary motor 5 may have a function of starting the engine 1, for example, when starting the engine 1, the secondary motor 5 may rotate a crankshaft of the engine 1 to bring a piston of the engine 1 to an ignition position, thereby starting the engine 1, so that the secondary motor 5 may perform a function of a starter in the related art.

As described above, both the engine 1 and the power motor 2 can be used to drive the wheels 7 of the hybrid vehicle. For example, as shown in fig. 2a, the engine 1 and the power motor 2 jointly drive the same wheel of the hybrid vehicle, such as a pair of front wheels 71 (including left and right front wheels); as another example, as shown in fig. 2b, engine 1 may drive a first wheel of the hybrid vehicle, such as a pair of front wheels 71 (including left and right front wheels), and power motor 2 may drive force to a second wheel of the hybrid vehicle, such as a pair of rear wheels 72 (including left and right rear wheels).

In other words, when the engine 1 and the power motor 2 jointly drive the pair of front wheels 71, the driving force of the power system is output to the pair of front wheels 71, and the whole vehicle can adopt a two-wheel drive driving mode; when the engine 1 drives the pair of front wheels 71 and the power motor 2 drives the pair of rear wheels 72, the driving force of the power system is respectively output to the pair of front wheels 71 and the pair of rear wheels 72, and the whole vehicle can adopt a four-wheel drive driving mode.

Further, when the engine 1 and the power motor 2 drive the same wheel together, as shown in fig. 2a, the power system of the hybrid vehicle further includes a final drive 8 and a transmission 90, wherein the engine 1 outputs power to a first wheel, for example, a pair of front wheels 71, of the hybrid vehicle through the clutch 6, the transmission 90 and the final drive 8, and the power motor 2 outputs driving force to the first wheel, for example, a pair of front wheels 71, of the hybrid vehicle through the final drive 8. Wherein the clutch 6 and the transmission 90 may be provided integrally.

When the engine 1 drives a first wheel and the power motor 2 drives a second wheel, as shown in fig. 2b, the power system of the hybrid vehicle further includes a first transmission 91 and a second transmission 92, wherein the engine 1 outputs power to the first wheel, for example, a pair of front wheels 71, of the hybrid vehicle through the clutch 6 and the first transmission 91, and the power motor 2 outputs driving force to the second wheel, for example, a pair of rear wheels 72, of the hybrid vehicle through the second transmission 92. Wherein the clutch 6 and the first transmission 91 may be provided integrally.

Further, in some embodiments of the present invention, as shown in fig. 1 to 3, the sub-motor 5 further includes a first controller 51, and the power motor 2 further includes a second controller 21, and the sub-motor 5 is connected to the power battery 3 and the DC-DC converter 4 through the first controller 51, and is connected to the power motor 2 through the first controller 51 and the second controller 21, respectively.

Specifically, the first controller 51 is connected to the second controller 21, the power battery 3, and the DC-DC converter 4, respectively, and the first controller 51 may have an AC-DC conversion unit that generates an alternating current when the sub-motor 5 generates electricity and converts the alternating current generated by the high-voltage motor 2 into a high-voltage direct current, for example, a 600V high-voltage direct current, so as to realize at least one of charging the power battery 3, supplying power to the power motor 2, and supplying power to the DC-DC converter 4.

Similarly, the second controller 21 may have a DC-AC conversion unit, and the first controller 51 may convert the alternating current generated by the sub-motor 5 into a high-voltage direct current, and the DC-AC conversion unit may convert the high-voltage direct current converted by the first controller 51 into an alternating current to supply the power motor 2.

In other words, as shown in fig. 3, when the sub-motor 5 generates power, the sub-motor 5 may charge the power battery 3 and/or supply power to the DC-DC converter 4 through the first controller 51. In addition, the auxiliary motor 5 can also supply power to the power motor 2 through the first controller 51 and the second controller 21.

Further, as shown in fig. 1 to 3, the DC-DC converter 4 is also connected to the power battery 3. The DC-DC converter 4 is also connected to the power motor 2 via a second controller 21.

In some embodiments, as shown in fig. 3, the first controller 51 has a first DC terminal DC1, the second controller 21 has a second DC terminal DC2, the DC-DC converter 4 has a third DC terminal DC3, and the third DC terminal DC3 of the DC-DC converter 4 can be connected to the first DC terminal DC1 of the first controller 51 to perform DC-DC conversion on the high-voltage DC output by the first controller 51 through the first DC terminal DC 1. Furthermore, the third DC terminal DC3 of the DC-DC converter 4 can be further connected to the power battery 3, and the first DC terminal DC1 of the first controller 51 can be further connected to the power battery 3, so that the first controller 51 outputs high-voltage DC power to the power battery 3 through the first DC terminal DC1 to charge the power battery 3. Further, the third DC terminal DC3 of the DC-DC converter 4 may be further connected to the second DC terminal DC2 of the second controller 21, and the first DC terminal DC1 of the first controller 51 may be further connected to the second DC terminal DC2 of the second controller 21, so that the first controller 51 outputs high voltage DC to the second controller 21 through the first DC terminal DC1 to power the power motor 2.

Further, as shown in fig. 3, the DC-DC converter 4 is also connected to the first electrical device 10 and the low-voltage battery 20 in the hybrid vehicle to supply power to the first electrical device 10 and the low-voltage battery 20, respectively, and the low-voltage battery 20 is also connected to the first electrical device 10.

In some embodiments, as shown in fig. 3, the DC-DC converter 4 further has a fourth DC terminal DC4, and the DC-DC converter 4 can convert the high-voltage DC output from the power battery 3 and/or the high-voltage DC output from the sub-motor 5 through the first controller 51 into low-voltage DC and output the low-voltage DC through the fourth DC terminal DC 4. Further, the fourth DC terminal DC4 of the DC-DC converter 4 can be connected to the first electrical device 10 to supply power to the first electrical device 10, wherein the first electrical device 10 can be a low voltage electric device, including but not limited to a car light, a radio, etc. The fourth DC terminal DC4 of the DC-DC converter 4 can also be connected to the low-voltage battery 20 in order to charge the low-voltage battery 20.

And, the low-voltage battery 20 is connected with the first electrical equipment 10 to supply power to the first electrical equipment 10, especially, when the auxiliary motor 5 stops generating power and the power battery 3 is out of order or the electric quantity is insufficient, the low-voltage battery 20 can supply power to the first electrical equipment 10, thereby ensuring the low-voltage power consumption of the whole vehicle, ensuring that the whole vehicle can realize the pure fuel mode driving, and improving the driving mileage of the whole vehicle.

As described above, the third DC terminal DC3 of the DC-DC converter 4 is connected to the first controller 51, and the fourth DC terminal DC4 of the DC-DC converter 4 is connected to the first electrical appliance 10 and the low-voltage battery 20, respectively, and when the power motor 2, the second controller 21, and the power battery 3 fail, the sub-motor 5 may generate power to supply power to the first electrical appliance 10 through the first controller 51 and the DC-DC converter 4 and/or to charge the low-voltage battery 20, so that the hybrid vehicle travels in a pure fuel mode.

In other words, when the power motor 2, the second controller 21, and the power battery 3 are out of order, the first controller 51 may convert the alternating current generated by the sub-motor 5 into the high-voltage direct current, and the DC-DC converter 4 may convert the high-voltage direct current converted by the first controller 50 into the low-voltage direct current to supply power to the first electrical appliance 10 and/or charge the low-voltage storage battery 20.

Therefore, the auxiliary motor 5 and the DC-DC converter 4 are provided with one independent power supply channel, when the power motor 2, the second controller 21 and the power battery 3 are in failure, electric driving cannot be realized, and at the moment, low-voltage power consumption of the whole vehicle can be ensured through the independent power supply channels of the auxiliary motor 5 and the DC-DC converter 4, so that the whole vehicle can be ensured to run in a pure fuel mode, and the running mileage of the whole vehicle is improved.

Further referring to the embodiment of fig. 3, the first controller 51, the second controller 21 and the power battery 3 are also respectively connected to the second electrical equipment 30 in the hybrid vehicle.

In some embodiments, as shown in fig. 3, the first DC terminal DC1 of the first controller 51 may be connected to the second electrical device 30, and when the sub-motor 5 generates power, the sub-motor 5 may directly supply power to the second electrical device 30 through the first controller 51. In other words, the AC-DC conversion unit of the first controller 51 may also convert the alternating current generated by the sub-motor 5 into the high-voltage direct current and directly supply the second electrical device 30 with the power.

Similarly, the power battery 3 can also be connected to the second electrical device 30 to power the second electrical device 30. That is, the high-voltage direct current output from the power battery 3 may be directly supplied to the second electrical equipment 30.

The second electrical device 30 may be a high voltage electrical device, and may include, but is not limited to, an air conditioner compressor, a PTC (Positive Temperature Coefficient) heater, and the like.

As above, by generating electricity by the sub-motor 5, it is possible to charge the power battery 3, or supply power to the power motor 2, or supply power to the first electrical apparatus 10 and the second electrical apparatus 30. Furthermore, the power battery 3 can supply power to the power motor 2 through the second controller 21, or supply power to the second electrical equipment 30, or supply power to the first electrical equipment 10 and/or the low-voltage storage battery 20 through the DC-DC converter 4. Therefore, the power supply mode of the whole vehicle is enriched, the power consumption requirements of the whole vehicle under different working conditions are met, and the performance of the whole vehicle is improved.

It should be noted that, in the embodiment of the present invention, the low voltage may refer to a voltage of 12V (volt) or 24V, and the high voltage may refer to a voltage of 600V, but is not limited thereto.

Therefore, in the power system of the hybrid electric vehicle, the engine does not participate in driving at low speed, so that the clutch is not used, the abrasion or the sliding wear of the clutch is reduced, the pause and the frustration are reduced, the comfort is improved, the engine can work in an economic area at low speed, only power is generated and is not driven, the oil consumption is reduced, the noise of the engine is reduced, the low-speed electric balance and the low-speed smoothness of the whole vehicle are maintained, and the performance of the whole vehicle is improved. Moreover, the auxiliary motor can directly charge the power battery, can also supply power for low-voltage devices such as a low-voltage storage battery, first electrical equipment and the like, and can also be used as a starter.

A specific embodiment of the power system of the hybrid electric vehicle is described in detail below with reference to fig. 4, and the embodiment is applicable to a power system in which the engine 1 and the power motor 2 jointly drive the same wheel, i.e., a two-wheel hybrid electric vehicle. It should be noted that this embodiment mainly describes a specific transmission structure among the engine 1, the power motor 2 and the wheels 7, especially the structure of the transmission 90 in fig. 2a, and the rest is basically the same as the embodiment in fig. 1 and 3, and will not be described in detail here.

It should be noted that the plurality of input shafts, the plurality of output shafts, the motor power shaft 931, the associated gears on each shaft, the shifting elements, etc. in the following embodiments may be used to form the transmission 90 of fig. 2 a.

In some embodiments, as shown in fig. 1, 3 and 4, a power system of a hybrid vehicle mainly includes an engine 1, a power motor 2, a power battery 3, a DC-DC converter 4, a sub-motor 5, a plurality of input shafts (e.g., a first input shaft 911, a second input shaft 912), a plurality of output shafts (e.g., a first output shaft 921, a second output shaft 922) and a motor power shaft 931, and associated gears and shifting elements (e.g., synchronizers) on the respective shafts.

As shown in fig. 4, the engine 1 outputs power to the wheels 7 of the hybrid vehicle through a clutch 6, such as a double clutch 2d in the example of fig. 4. In power transmission between the engine 1 and the input shafts, the engine 1 is configured to selectively engage at least one of the plurality of input shafts through the double clutch 2 d. In other words, while the engine 1 transmits power to the input shafts, the engine 1 can be selectively engaged with one of the plurality of input shafts to transmit power, or the engine 1 can also be selectively engaged with two or more of the plurality of input shafts at the same time to transmit power.

For example, in the example of fig. 4, the plurality of input shafts may include two input shafts, a first input shaft 911 and a second input shaft 912, the second input shaft 912 may be coaxially sleeved on the first input shaft 911, and the engine 1 may be selectively engaged with one of the first input shaft 911 and the second input shaft 912 through the dual clutch 2d to transmit power. Alternatively, in particular, the engine 1 can also be engaged simultaneously with the first input shaft 911 and the second input shaft 912 to transmit power. Of course, it should be understood that the engine 1 may also be disconnected from both the first input shaft 911 and the second input shaft 912.

The plurality of output shafts may include two output shafts, a first output shaft 921 and a second output shaft 922, the first output shaft 921 and the second output shaft 922 being arranged in parallel with the first input shaft 911.

The input shaft and the output shaft can be transmitted through a gear pair. For example, each input shaft is provided with a gear driving gear, that is, each of the first input shaft 911 and the second input shaft 912 is provided with a gear driving gear, each output shaft is provided with a gear driven gear, that is, each of the first output shaft 921 and the second output shaft 922 is provided with a gear driven gear, and the gear driven gears are correspondingly engaged with the gear driving gears, so as to form a plurality of pairs of gear pairs with different gear ratios.

In some embodiments of the present invention, a six-gear transmission may be adopted between the input shaft and the output shaft, that is, there are a first-gear pair, a second-gear pair, a third-gear pair, a fourth-gear pair, a fifth-gear pair and a sixth-gear pair. However, the present invention is not limited to this, and it is obvious to those skilled in the art that the number of gear pairs can be increased or decreased according to the transmission requirement, and is not limited to the six-gear transmission shown in the embodiment of the present invention.

As shown in fig. 4, the motor power shaft 931 is provided so as to be interlocked with one of the plurality of output shafts (e.g., the first output shaft 921, the second output shaft 922), and power is transmitted between the motor power shaft 931 and the one of the output shafts by the motor power shaft 931 being interlocked with the one of the output shafts. For example, power output via the output shaft (e.g., power output from the engine 1) may be output to the motor power shaft 931, or power output via the motor power shaft 931 (e.g., power output from the power motor 2) may also be output to the output shaft.

It should be noted that the above-mentioned "linkage" may be understood as a linkage movement of a plurality of members (for example, two members), and in the case of linkage of two members, when one member moves, the other member also moves.

For example, in some embodiments of the present invention, a gear in communication with a shaft may be understood such that when the gear rotates, the shaft in communication therewith will also rotate, or when the shaft rotates, the gear in communication therewith will also rotate.

As another example, a shaft is coupled to a shaft is understood to mean that when one of the shafts rotates, the other shaft coupled thereto will also rotate.

As another example, gears may be understood to be geared with one gear so that when one gear rotates, the other gear that is geared with it will also rotate.

In the following description of the present invention, the term "linkage" is to be understood unless otherwise specified.

Similarly, the power motor 2 is provided so as to be interlocked with the motor power shaft 931, for example, the power motor 2 may output the generated power to the motor power shaft 931 so as to output the driving force to the wheels 7 of the hybrid vehicle through the motor power shaft 931.

It should be noted that in the description of the present invention, the motor power shaft 931 may be a motor shaft of the power motor 2 itself. Of course, it will be understood that the motor power shaft 931 and the motor shaft of the power motor 2 may also be two separate shafts.

In some embodiments, as shown in fig. 4, the output portion 221 is differentially rotatable with respect to the one of the output shafts (e.g., the second output shaft 922), in other words, the output portion 221 and the output shaft are independently rotatable at different rotational speeds.

Further, the output portion 221 is configured to selectively engage the one of the output shafts for synchronous rotation therewith, in other words, the output portion 221 is capable of differential or synchronous rotation relative thereto. In short, the output portion 221 is engageable for synchronous rotation with respect to the one of the output shafts, but is disengageable for differential rotation.

As shown in fig. 4, the output portion 221 may be disposed on the one of the output shafts in a blank manner, but is not limited thereto. For example, in the example of fig. 4, the output portion 221 is freely sleeved on the second output shaft 922, i.e., the output portion 221 and the second output shaft 922 can rotate at different rotational speeds and different speeds.

As described above, the output portion 221 is rotatable in synchronization with the one of the output shafts, and for example, the synchronization of the output portion 221 with the output shaft can be achieved by adding a corresponding synchronizer as needed. The synchronizer may be an output synchronizer 221c, the output synchronizer 221c being arranged for synchronizing the output 221 and the one of the output shafts.

In some embodiments, the power motor 2 is used to output driving force to the wheels 7 of the hybrid vehicle, and the engine 1 and the power motor 2 drive the same wheels of the hybrid vehicle together. In connection with the example of fig. 4, a differential 75 of the vehicle may be arranged between a pair of front wheels 71 or between a pair of rear wheels 72, in some examples of the invention, the differential 75 may be located between a pair of front wheels 71 when the power motor 2 drives the pair of front wheels 71.

The function of the differential 75 is to allow the left and right drive wheels to roll at different angular velocities when the vehicle is traveling around a curve or over an uneven surface to ensure a pure rolling motion between the drive wheels on both sides and the ground. A final drive driven gear 74 of the final drive 8 is provided on the differential 75, for example, the final drive driven gear 74 may be arranged on a case of the differential 75. The final drive driven gear 74 may be a bevel gear, but is not limited thereto.

In some embodiments, as shown in fig. 1, a power battery 3 is used to power the power motor 2; the auxiliary motor 5 is connected with the engine 1, the auxiliary motor 5 is also connected with the power motor 2, the DC-DC converter 4 and the power battery 3 respectively, and the auxiliary motor 5 realizes at least one of charging the power battery 3, supplying power to the power motor 2 and supplying power to the DC-DC converter 4 when driven by the engine 1 to generate power.

In the following, another embodiment of the power system of the hybrid electric vehicle will be described in detail with reference to fig. 5, and the embodiment is also applicable to a power system in which the engine 1 and the power motor 2 jointly drive the same wheel, i.e. a two-wheel hybrid electric vehicle. It should be noted that this embodiment mainly describes a specific transmission structure among the engine 1, the power motor 2 and the wheels 7, especially the structure of the transmission 90 in fig. 2a, and the rest is basically the same as the embodiment in fig. 1 and 3, and will not be described in detail here.

In some embodiments, as shown in fig. 1, 3 and 5, a power system of a hybrid vehicle mainly includes an engine 1, a power motor 2, a power battery 3, a DC-DC converter 4, a sub-motor 5, a plurality of input shafts (e.g., a first input shaft 911, a second input shaft 912), a plurality of output shafts (e.g., a first output shaft 921, a second output shaft 922) and a motor power shaft 931, and associated gears and shifting elements (e.g., synchronizers) on the respective shafts.

As shown in fig. 5, the engine 1 outputs power to the wheels 7 of the hybrid vehicle through a clutch 6, such as the double clutch 2d in the example of fig. 4. In power transmission between the engine 1 and the input shafts, the engine 1 is configured to selectively engage at least one of the plurality of input shafts through the double clutch 2 d. In other words, while the engine 1 transmits power to the input shafts, the engine 1 can be selectively engaged with one of the plurality of input shafts to transmit power, or the engine 1 can also be selectively engaged with two or more of the plurality of input shafts at the same time to transmit power.

For example, in the example of fig. 5, the plurality of input shafts may include two input shafts, a first input shaft 911 and a second input shaft 912, the second input shaft 912 is coaxially sleeved on the first input shaft 911, and the engine 1 can be selectively engaged with one of the first input shaft 911 and the second input shaft 912 through the dual clutch 2d to transmit power. Alternatively, in particular, the engine 1 can also be engaged simultaneously with the first input shaft 911 and the second input shaft 912 to transmit power. Of course, it should be understood that the engine 1 may also be disconnected from both the first input shaft 911 and the second input shaft 912.

As shown in fig. 5, at least one reverse output gear 81 is provided on one of the output shafts (e.g., the first output shaft 921 and the second output shaft 922) in a hollow manner, and a reverse synchronizer (e.g., the fifth synchronizer 5c, the sixth synchronizer 6c) for engaging the reverse output gear 81 is further provided on the output shaft, in other words, the reverse synchronizer synchronizes the corresponding reverse output gear 81 and the output shaft, so that the output shaft and the reverse output gear 81 synchronized by the reverse synchronizer can be rotated in synchronization, and thus reverse power can be output from the output shaft.

In some embodiments, as shown in FIG. 5, there is one reverse output gear 81, and the one reverse output gear 81 may be idle on the second output shaft 922. However, the present invention is not limited thereto, and in other embodiments, the reverse output gear 81 may be two, and the two reverse output gears 81 are simultaneously fitted over the second output shaft 922. Of course, it is understood that the reverse output gear 81 may be three or more.

The reverse shaft 89 is provided so as to be interlocked with one of the input shafts (e.g., the first input shaft 911 and the second input shaft 912) and also with at least one reverse output gear 81, for example, power on the one of the input shafts can be transmitted to the reverse output gear 81 through the reverse shaft 89, so that the reverse power can be output from the reverse output gear 81. In the example of the present invention, the reverse output gears 81 are all freely engaged with the second output shaft 922, and the reverse shaft 89 is interlocked with the first input shaft 911, so that, for example, the reverse power output from the engine 1 can be output to the reverse output gears 81 through the first input shaft 911 and the reverse shaft 89.

The motor power shaft 931 is described in detail below. A first gear 31 of the motor power shaft and a second gear 32 of the motor power shaft are sleeved on the motor power shaft 931. The motor power shaft first gear 31 may be in meshing transmission with the final drive driven gear 74 to transmit the driving force to the wheels 7 of the hybrid vehicle.

The second motor power shaft gear 32 is arranged to be linked with one of the gear driven gears, and when a hybrid electric vehicle with the power system according to the embodiment of the invention is in some working conditions, the power output by the power source can be transmitted between the second motor power shaft gear 32 and the gear driven gear linked with the second motor power shaft gear 32, and the second motor power shaft gear 32 is linked with the gear driven gear. For example, the second motor power shaft gear 32 is linked with the second gear driven gear 2b, and the second motor power shaft gear 32 and the second gear driven gear 2b may be directly engaged or indirectly driven through an intermediate transmission member.

Further, a motor power shaft synchronizer 33c is also provided on the motor power shaft 931, the motor power shaft synchronizer 33c being located between the motor power shaft first gear 31 and the motor power shaft second gear 32, the motor power shaft synchronizer 33c being operable to selectively engage either the motor power shaft first gear 31 or the motor power shaft second gear 32 with the motor power shaft 3. For example, in the example of FIG. 5, moving the engagement sleeve of the motor power shaft synchronizer 33c to the left may engage the motor power shaft second gear 32 and moving to the right may engage the motor power shaft first gear 31.

As for the motor power shaft first gear 31, since it is meshed with the final drive driven gear 74, the power motor 2 can directly output the generated power from the motor power shaft first gear 31 by engaging the motor power shaft first gear 31 with the motor power shaft synchronizer 33c, which can shorten the transmission chain, reduce intermediate transmission components, and improve the transmission efficiency.

Next, the transmission mode of the motor power shaft 931 and the power motor 2 will be described in detail with reference to specific embodiments.

In some embodiments, as shown in fig. 5, a motor power shaft third gear 33 is further fixedly disposed on the motor power shaft 931, and the power motor 2 is disposed to be directly meshed with or indirectly driven by the motor power shaft third gear 33.

Further, a first motor gear 511 is arranged on a motor shaft of the power motor 2, and the first motor gear 511 is in transmission with a third motor power shaft gear 33 through an intermediate gear 512. For another example, the power motor 2 and the motor power shaft 931 may be coaxially connected.

In some embodiments, the power motor 2 is used to output driving force to the wheels 7 of the hybrid vehicle, and the engine 1 and the power motor 2 drive the same wheels of the hybrid vehicle together. In connection with the example of fig. 5, a differential 75 of the vehicle may be arranged between a pair of front wheels 71 or between a pair of rear wheels 72, in some examples of the invention, the differential 75 may be located between a pair of front wheels 71 when the power motor 2 drives the pair of front wheels 71.

Further, a first output shaft output gear 211 is fixedly provided on the first output shaft 921, the first output shaft output gear 211 rotates synchronously with the first output shaft 921, and the first output shaft output gear 211 is in mesh transmission with the final drive driven gear 74, so that the power passing through the first output shaft 921 can be transmitted from the first output shaft output gear 211 to the final drive driven gear 74 and the differential 75.

Similarly, a second output shaft output gear 212 is fixedly arranged on the second output shaft 922, the second output shaft output gear 212 rotates synchronously with the second output shaft 922, the second output shaft output gear 212 is in mesh transmission with the final drive driven gear 74, and thus the power through the second output shaft 922 can be transmitted from the second output shaft output gear 212 to the final drive driven gear 74 and the differential 75.

Similarly, the motor power shaft first gear 31 may be used to output power through the motor power shaft 931, and therefore the motor power shaft first gear 31 is also in meshing transmission with the final drive driven gear 74.

In some embodiments, as shown in fig. 1, a power battery 3 is used to power the power motor 2; the auxiliary motor 5 is connected with the engine 1, the auxiliary motor 5 is also connected with the power motor 2, the DC-DC converter 4 and the power battery 3 respectively, and when the auxiliary motor 5 is driven by the engine 1 to generate electricity, at least one of charging the power battery 3, supplying power to the power motor 2 and supplying power to the DC-DC converter 4 is realized.

Further, as shown in fig. 6, the power system of the hybrid electric vehicle further includes a control module 101, and the control module 101 is configured to control the power system of the hybrid electric vehicle. It should be understood that the control module 101 may be an integration of a controller having a control function in a hybrid vehicle, such as a vehicle controller of the hybrid vehicle, the first controller 51 and the second controller 21 in the embodiment of fig. 3, and the like, but is not limited thereto. The control method performed by the control module 101 is described in detail below.

In some embodiments of the present invention, the control module 101 is configured to obtain an SOC value (stateof charge) of the power battery 3, an SOC value of the low-voltage battery 20, and a vehicle speed of the hybrid vehicle, and control the secondary motor 5 to enter a generated power regulation mode according to the SOC value of the power battery 3 and the vehicle speed of the hybrid vehicle, so that the engine 1 operates in a preset optimal economic region, wherein after the secondary motor 5 enters the generated power regulation mode, the control module 101 is further configured to regulate the generated power of the secondary motor 5 according to the SOC value of the low-voltage battery 20. The generated power adjusting mode is a mode for adjusting the generated power of the engine, and in the generated power adjusting mode, the engine 1 can be controlled to drive the auxiliary motor 5 to generate power so as to adjust the generated power of the auxiliary motor 5. It should be noted that the SOC value of the power battery 3 and the SOC value of the low-voltage battery 20 may be collected by a battery management system of the hybrid vehicle, so that the battery management system sends the collected SOC value of the power battery 3 and the collected SOC value of the low-voltage battery 20 to the control module 101, so that the control module 101 acquires the SOC value of the power battery 3 and the SOC value of the low-voltage battery 20.

It is also noted that the preset optimum economy region of the engine 1 may be determined in conjunction with the engine-owned characteristic map. Fig. 7 shows an example of an engine universal characteristic diagram in which the side ordinate is the output torque of the engine 1, the abscissa is the rotation speed of the engine 1, and the curve a is the fuel economy curve of the engine 1. The fuel economy curve corresponds to an optimal economy region of the engine, that is, when the torque and the torque of the engine 1 are on the optimal fuel economy curve of the engine, the engine is in the optimal economy region. Thus, in the present embodiment, the control module 101 may operate the engine 1 in a predetermined optimal economy zone by controlling the speed and output torque of the engine 1 to fall on an engine fuel economy curve, such as curve a.

Specifically, during the running of the hybrid vehicle, the engine 1 can output power to the wheels 7 of the hybrid vehicle through the clutch 6, and the engine 1 can also drive the auxiliary motor 5 to generate power. Therefore, the output power of the engine mainly includes two parts, one part is output to the sub-motor 5, that is, the generated power for driving the sub-motor 5 to generate electricity, and the other part is output to the wheels 7, that is, the driving power for driving the wheels 7.

When the engine 1 drives the secondary motor 5 to generate power, the control module 101 may first obtain the SOC value of the power battery 3 and the speed of the hybrid vehicle, and then control the secondary motor 5 to enter a power generation regulation mode according to the SOC value of the power battery 3 and the speed of the hybrid vehicle, so that the engine 1 operates in a preset optimal economic area. In the generated power adjustment mode, the control module 101 may adjust the generated power of the sub-motor 5 on the premise of operating the engine 1 in a preset optimum economy zone. After the sub-motor 5 enters the generated power adjusting mode, the control module 101 further adjusts the generated power of the sub-motor 5 according to the SOC value of the low-voltage battery 20.

More specifically, in one embodiment of the present invention, the control module 101 is further configured to control the generated power of the sub-motor 5 based on the SOC value of the power battery 3, the SOC value of the low-voltage battery 20, and the vehicle speed of the hybrid vehicle, and to obtain the generated power of the engine 1 based on the generated power of the sub-motor 5 to control the engine 1 to operate in a preset optimum economy zone.

Therefore, the engine 1 can work in the preset optimal economic area, and the oil consumption of the engine 1 is the lowest and the fuel economy is the highest in the preset optimal economic area, so that the oil consumption of the engine 1 can be reduced, the noise of the engine 1 is reduced, and the running economy of the whole vehicle is improved. Moreover, the auxiliary motor 5 has higher generating power and generating efficiency at low speed, so that the power utilization requirement of low-speed running can be met, the low-speed electric balance of the whole vehicle can be maintained, the low-speed ride comfort of the whole vehicle is maintained, and the power performance of the whole vehicle is improved. The power battery is charged, so that the power demand of the power motor and the high-voltage electrical equipment can be ensured, the normal running of the whole vehicle driven by the power motor can be ensured, the power demand of the low-voltage electrical equipment can be ensured by charging the low-voltage storage battery, the low-voltage power supply of the whole vehicle can be realized through the low-voltage storage battery when the auxiliary motor stops generating power and the power battery fails or has insufficient electric quantity, the pure fuel mode running of the whole vehicle can be ensured, and the running mileage of the whole vehicle can be improved.

Further, according to an embodiment of the present invention, the control module 101 is configured to: when the SOC value of the power battery 3 is larger than a preset limit value and smaller than or equal to a first preset value, if the speed of the hybrid electric vehicle is smaller than a first preset speed, the auxiliary motor 5 is controlled to enter a generated power regulation mode.

The first preset value may be an upper limit value of the SOC value of the power battery 3, which is set in advance, for example, a determination value for stopping charging, and may preferably be 30%. The preset limit value may be a lower limit value of the SOC value of the power battery 3 set in advance, for example, a determination value for stopping discharge, and may preferably be 10%. The SOC value of the power battery 3 can be divided into three intervals, namely a first electric quantity interval, a second electric quantity interval and a third electric quantity interval, according to a first preset value and a preset limit value, when the SOC value of the power battery 3 is smaller than or equal to the preset limit value, the SOC value of the power battery 3 is in the first electric quantity interval, and at the moment, the power battery 3 is charged and is not discharged; when the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value, the SOC value of the power battery 3 is in a second electric quantity interval, and at the moment, the power battery 3 has a charging requirement, so that the power battery 3 can be actively charged; when the SOC value of the power battery 3 is greater than the first preset value, the SOC value of the power battery 3 is in the third electric quantity interval, and at this time, the power battery 3 may not be charged, that is, the power battery 3 may not be actively charged.

Specifically, after acquiring the SOC value of the power battery 3 and the vehicle speed of the hybrid vehicle, the control module 101 may determine an interval where the SOC value of the power battery 3 is located, if the SOC value of the power battery 3 is in the second electric quantity interval, and the SOC value of the power battery 3 is greater than a preset limit value and is less than or equal to a first preset value, it is determined that the power battery 3 may be charged, at this time, the control module 101 further determines whether the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, and if the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, the sub-motor 5 is controlled to enter a generated power regulation mode, at this time, the vehicle speed of the hybrid vehicle is low, the required driving force is small, the power motor 2 is sufficient to drive the hybrid vehicle to run, and the engine 1 may only drive the sub-motor 5 to generate power.

Therefore, the engine only generates power and does not participate in driving at low speed, and the clutch does not need to be used because the engine does not participate in driving, so that the abrasion or the sliding abrasion of the clutch can be reduced, the pause and the contusion are reduced, and the comfort is improved.

Further, the control module 101 is further configured to: when the SOC value of the power battery 3 is larger than a preset limit value and smaller than or equal to a first preset value and the speed of the hybrid electric vehicle is smaller than a first preset speed, acquiring the required power of the whole hybrid electric vehicle, and when the required power of the whole hybrid electric vehicle is smaller than or equal to the maximum allowable power generation power of the auxiliary motor 5, controlling the auxiliary motor 5 to enter a power generation power regulation mode.

That is to say, after the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value and the speed of the hybrid electric vehicle is less than the first preset speed, the control module 101 may further determine whether the required power of the entire vehicle is greater than the maximum allowable power generation power of the secondary motor 5, and if the required power of the entire vehicle is less than or equal to the maximum allowable power generation power of the secondary motor 5, the secondary motor 5 is controlled to enter the power generation power adjustment mode, at this time, the required driving force of the entire vehicle is small, the required power of the entire vehicle is small, the power motor 2 is sufficient to drive the hybrid electric vehicle, and the engine 1 may only drive the secondary motor 5 to generate power without participating in driving.

Still further, the control module 101 is further configured to: when the SOC value of the power battery is larger than a preset limit value and smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the required power of the whole vehicle is smaller than or equal to the maximum allowable power generation power of the auxiliary motor, the depth of an accelerator pedal of the hybrid electric vehicle and the whole vehicle resistance of the hybrid electric vehicle are obtained, and when the depth of the accelerator pedal is smaller than or equal to the first preset depth and the whole vehicle resistance of the hybrid electric vehicle is smaller than or equal to the first preset resistance, the auxiliary motor is controlled to enter a power generation regulation mode.

The overall vehicle resistance of the hybrid vehicle may be the driving resistance of the hybrid vehicle, such as rolling resistance, acceleration resistance, gradient resistance, air resistance, and the like.

That is, after determining that the SOC value of the power battery 3 is greater than the preset limit value and less than or equal to the first preset value, the vehicle speed of the hybrid vehicle is less than the first preset vehicle speed, and the power demand of the entire vehicle is less than or equal to the maximum allowable power generation power of the secondary motor 5, the control module 101 may further determine whether the accelerator pedal depth is greater than the first preset depth and the entire vehicle resistance of the hybrid vehicle is greater than the first preset resistance, and if the accelerator pedal depth is less than or equal to the first preset depth or the entire vehicle resistance of the hybrid vehicle is less than or equal to the first preset resistance, the secondary motor 5 is controlled to enter the power generation adjustment mode, at this time, the driving force required by the entire vehicle is small, the power demand of the entire vehicle is small, the accelerator pedal depth is small, the entire vehicle resistance is small, the power motor 2 is sufficient to drive the hybrid vehicle, and the engine 1 may only, and does not participate in driving.

As above, when the hybrid electric vehicle is running at a low speed, the engine 1 can only generate electricity and does not participate in driving, and the clutch does not need to be used because the engine does not participate in driving, so that the abrasion or the sliding wear of the clutch can be reduced, the pause and contusion can be reduced, the comfort is improved, moreover, the engine can work in an economic area at the low speed, because the oil consumption of the engine in a preset optimal economic area is lowest, and the fuel economy is highest, so that the oil consumption can be reduced, the noise of the engine is reduced, the running economy of the whole vehicle is improved, the low-speed electric balance and the low-speed smoothness of the whole vehicle are maintained, and the performance of the whole vehicle.

According to an embodiment of the present invention, the control module 101 is further configured to: when the engine 1 is controlled to drive the auxiliary motor 5 to generate power independently and the power motor 2 is controlled to output driving force independently, the power generated by the engine 1 is obtained according to the following formula:

P0＝P1/η/ζ

where P0 is the generated power of the engine 1, P1 is the generated power of the sub-motor 5, η belt transmission efficiency, and ζ is the efficiency of the sub-motor 5.

That is, in the case where the engine 1 can generate only power without participating in driving, the control module 101 may calculate the generated power P0 of the engine 1 from the generated power of the sub-motor 5, the belt transmission efficiency η, and the efficiency ζ of the sub-motor 5, and control the engine 1 to drive the sub-motor 5 to generate power with the acquired generated power P0 to control the generated power of the sub-motor 5.

Additionally, according to an embodiment of the present invention, the control module 101 is further configured to: when the SOC value of the power battery 3 is smaller than a preset limit value, or the speed of the hybrid electric vehicle is larger than or equal to a first preset speed, or the required power of the whole vehicle is larger than the maximum allowable power generation power of the auxiliary motor 5, or the depth of an accelerator pedal is larger than a first preset depth, or the resistance of the whole vehicle of the hybrid electric vehicle is larger than a first preset resistance, the engine 1 is controlled to participate in driving.

That is to say, when the SOC value of the power battery 3 is less than the preset limit value M2, or the vehicle speed of the hybrid vehicle is greater than or equal to the first preset vehicle speed, or the power demanded by the entire vehicle is greater than the maximum allowable power generation of the sub-motor 5, or the depth of the accelerator pedal is greater than the first preset depth, or the resistance of the entire vehicle of the hybrid vehicle is greater than the first preset resistance, the control module 101 controls the engine 1 to participate in driving, at this time, the power battery 3 does not discharge any more, the driving force required by the entire vehicle is greater, the power demanded by the entire vehicle is greater, the depth of the accelerator pedal is greater, or the resistance of the entire vehicle is greater, the power motor 2 is not sufficient to drive the hybrid vehicle.

Therefore, the engine 1 can participate in driving when the driving force output by the power motor 2 is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved.

More specifically, the control module 101 is further configured to: when the required power of the whole vehicle is larger than the maximum allowable power generation power of the auxiliary motor 5, the engine 1 is also controlled to participate in driving so that the engine 1 outputs power to wheels through the clutch 6.

And, the control module 101 is further configured to: when the SOC value of the power battery 3 is less than or equal to a preset limit value, controlling the engine 1 to participate in driving so that the engine 1 outputs power to wheels through the clutch 6; when the SOC value of the power battery 3 is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed and the depth of an accelerator pedal is larger than a first preset depth, controlling the engine 1 to participate in driving so that the engine 1 outputs power to wheels through the clutch 6; when the SOC value of the power battery 3 is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the overall resistance of the hybrid electric vehicle is larger than the first preset resistance, the engine 1 participates in driving so that the engine 1 outputs power to wheels through the clutch 6.

That is to say, the control module 101 can obtain the SOC value of the power battery 3, the accelerator pedal depth of the hybrid electric vehicle, the vehicle speed, the vehicle resistance and the vehicle required power in real time, and judge the SOC value of the power battery 3, the accelerator pedal depth of the hybrid electric vehicle, the vehicle speed and the vehicle resistance:

firstly, when the SOC value of the power battery 3 is smaller than the preset limit value, the power battery 3 cannot provide enough electric energy due to the low electric quantity of the power battery 3, the control module 101 controls the engine 1 and the power motor 2 to participate in driving at the same time, at this time, the control module 101 can also control the engine 1 to drive the auxiliary motor 5 to generate electricity, and the engine 1 can work in the preset optimal economic area by adjusting the generated power of the auxiliary motor 5.

Secondly, when the SOC value of the power battery 3 is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the depth of an accelerator pedal is larger than a first preset depth, the control module 101 controls the engine 1 and the power motor 2 to participate in driving at the same time because the depth of the accelerator pedal is deeper, the control module 101 can also control the engine 1 to drive the secondary motor 5 to generate electricity, and the engine 1 can work in a preset optimal economic area by adjusting the power generation of the secondary motor 5.

Thirdly, when the SOC value of the power battery 3 is less than or equal to a first preset value, the speed of the hybrid electric vehicle is less than a first preset speed, and the overall resistance of the hybrid electric vehicle is greater than the first preset resistance, the control module 101 controls the engine 1 and the power motor 2 to participate in driving simultaneously because the overall resistance of the hybrid electric vehicle is greater, at the moment, the control module 101 can also control the engine 1 to drive the secondary motor 5 to generate electricity, and the engine 1 can work in a preset optimal economic area by adjusting the power generation of the secondary motor 5.

Therefore, the engine 1 can participate in driving when the driving force output by the power motor 2 is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved. And moreover, the engine can be controlled to work in an economic area, and the oil consumption of the engine 1 in a preset optimal economic area is the lowest, and the fuel economy is the highest, so that the oil consumption can be reduced, the noise of the engine is reduced, and the economic performance of the whole vehicle is improved.

In addition, the control module 101 is further configured to: when the SOC value of the power battery 3 is smaller than or equal to a preset limit value and the vehicle speed of the hybrid electric vehicle is larger than a first preset vehicle speed, the engine 1 is controlled to participate in driving so that the engine 1 outputs power to wheels 7 through a clutch 6.

Of course, it should be understood that the control module 101 is also operable to: when the SOC value of the power battery 3 is larger than the first preset value, the engine 1 does not drive the auxiliary motor 5 to generate power, at the moment, the electric quantity of the power battery 3 is close to full power and does not need to be charged, and the engine 1 does not drive the auxiliary motor 5 to generate power. That is, when the amount of power of the power battery 3 approaches the full charge, the engine 1 does not drive the sub-motor 5 to generate power, and the sub-motor 5 does not charge the power battery 3.

Further, after the sub-motor 5 enters the generated power adjusting mode, the control module 101 may adjust the generated power of the sub-motor 5, and the generated power adjusting process of the control module 101 according to the embodiment of the present invention is described in detail below.

According to an embodiment of the invention, the control module 101 is further configured to: when the auxiliary motor 5 enters the generated power regulation mode, the generated power of the auxiliary motor 5 is regulated according to the vehicle required power of the hybrid electric vehicle, the charging power of the power battery 3, the charging power of the low-voltage storage battery 20 and the SOC value of the low-voltage storage battery 20.

Specifically, the formula for adjusting the generated power of the sub-motor 5 in accordance with the vehicle-finished required power of the hybrid vehicle, the charging power of the power battery 3, and the charging power of the low-voltage battery 20 may be as follows:

P1-P2 + P3+ P4, wherein P2-P11 + P21,

wherein, P1 is the generated power of the auxiliary motor 5, P2 is the required power of the whole vehicle, P3 is the charging power of the power battery 3, P4 is the charging power of the low-voltage storage battery 20, P11 is the driving power of the whole vehicle, and P21 is the power of the electrical equipment.

It should be noted that the electrical devices include the first electrical device 10 and the second electrical device 30, that is, the electrical device power P21 may include power required by the high-voltage electrical device and the low-voltage electrical device.

It should be further noted that the vehicle driving power P11 may include the output power of the power motor 2, and the control module 101 may obtain the vehicle driving power P11 according to a preset throttle-torque curve of the power motor 2 and the rotation speed of the power motor 2, where the preset throttle-torque curve may be determined when the hybrid vehicle is power-matched; the control module 101 may obtain the electrical device power P21 in real time according to the electrical devices running on the entire vehicle, for example, calculate the electrical device power P21 through DC consumption on the bus; the control module 101 may obtain the charging power P3 of the power battery 3 according to the SOC value of the power battery 3 and obtain the charging power P4 of the low-voltage battery 20 according to the SOC value of the low-voltage battery 20.

Specifically, during the driving of the hybrid vehicle, the control module 101 may obtain the charging power P3 of the power battery 3, the charging power P4 of the low-voltage battery 20, the vehicle driving power P11, and the electrical equipment power P21, and use the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage battery 20, the vehicle driving power P11, and the electrical equipment power P21 as the generated power P1 of the secondary motor 5, so that the control module 101 may adjust the generated power of the secondary motor 5 according to the calculated P1 value, for example, the control module 101 may control the output torque and the rotation speed of the engine 1 according to the calculated P1 value, so as to adjust the power generated by the secondary motor 5 driven by the engine 1.

Further, according to an embodiment of the present invention, the control module 101 is further configured to: acquiring the SOC value change rate of the power battery 3, and adjusting the generating power of the secondary motor 5 according to the relation between the whole vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic area of the engine 1, the SOC value change rate of the power battery 3, the SOC value of the low-voltage storage battery 20 and the SOC value change rate of the low-voltage storage battery 20.

It should be understood that the control module 101 may obtain the SOC value change rate of the power battery 3 according to the SOC value of the power battery 3, for example, collect the SOC value of the power battery 3 once every time interval t, so that the ratio of the difference between the current SOC value and the previous SOC value of the power battery 3 and the time interval t may be used as the SOC value change rate of the power battery 3. Similarly, the SOC-value change rate of the low-voltage battery 20 may be obtained from the SOC value of the low-voltage battery 20, for example, the SOC value of the low-voltage battery 20 is collected once per time interval t, so that the ratio of the difference between the current SOC value and the previous SOC value of the low-voltage battery 20 to the time interval t may be taken as the SOC-value change rate of the low-voltage battery 20.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, and then the minimum output power Pmin corresponding to the optimal economic region of the engine may be obtained, and after determining the minimum output power Pmin corresponding to the optimal economic region of the engine, the control module 101 may adjust the generated power of the sub-motor 5 according to the relationship between the total vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine 1, the SOC value change rate of the power battery 3, the SOC value of the low-voltage battery 20, and the SOC value change rate of the low-voltage battery 20.

Therefore, when the hybrid electric vehicle runs at a low speed, the engine works in an economic area, the oil consumption can be reduced, the noise of the engine is reduced, the economic performance of the whole vehicle is improved, the engine 1 can only generate electricity and does not participate in driving at the low speed, and the clutch does not need to be used because the engine does not participate in driving, so that the abrasion or the sliding wear of the clutch can be reduced, the pause and contusion can be reduced, the comfort is improved, the low-speed electric balance and the low-speed ride comfort of the whole vehicle are maintained, and the performance of the whole vehicle is improved.

The specific adjustment manner of the control module 101 for adjusting the generated power of the sub-motor 5 according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic zone of the engine 1, the SOC value change rate of the power battery 3, the SOC value of the low-voltage battery 20, and the SOC value change rate of the low-voltage battery 20 when the sub-motor 5 enters the generated power adjustment mode will be further described below.

Specifically, the control module 101 is further configured to: when the SOC value of the low-voltage storage battery 20 is larger than a preset low-electricity threshold, acquiring the charging power P3 of the power battery 3 according to the SOC value change rate of the power battery 3, and judging whether the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the required power P2 of the whole vehicle, wherein if the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the required power P2 of the whole vehicle, the engine 1 is controlled to generate electricity with the minimum output power to adjust the electricity generation power of the secondary motor 5; if the charging power P3 of the power battery 3 is greater than or equal to the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the total vehicle demand power P2, the output power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the total vehicle demand power P2, and the engine 1 is controlled to generate electricity with the obtained output power to adjust the power generation power of the secondary motor 5.

Specifically, the control module 101 is further configured to: when the SOC value of the low-voltage storage battery 20 is less than or equal to a preset low-battery threshold value, acquiring the change rate of the SOC value of the low-voltage storage battery 20 and the change rate of the SOC value of the power battery 3, and acquires the charging power P4 of the low-voltage battery 20 according to the rate of change of the SOC value of the low-voltage battery 20 and the charging power P3 of the power battery 3 according to the rate of change of the SOC value of the power battery 3, and judging whether the sum of the charging power P4 of the low-voltage storage battery 20 and the charging power P3 of the power battery 3 is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic region of the engine 1 and the required power P2 of the whole vehicle, wherein, if the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 20 is less than the difference between the minimum output power Pmin corresponding to the optimal economic zone of the engine 1 and the required power P2 of the whole vehicle, the engine 1 is controlled to generate electricity at the minimum output power Pmin to adjust the generated power of the sub-motor 5; if the sum of the charging power P4 of the low-voltage storage battery 20 and the charging power P3 of the power battery 3 is greater than or equal to the difference between the minimum output power Pmin and the vehicle required power P2 corresponding to the optimal economic region of the engine 1, the output power of the engine 1 in the preset optimal economic region is acquired according to the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20 and the vehicle required power P2, and the generated power of the sub-motor 5 is adjusted by controlling the engine 1 to generate power with the acquired output power.

It should be noted that, the control module 101 may pre-store a first relation table between the SOC value change rate of the power battery 3 and the charging power P3 of the power battery 3, so that after the control module 101 obtains the SOC value change rate of the power battery 3, the control module can obtain the charging power P3 of the power battery 3 by comparing the first relation table. For example, a first relationship table between the rate of change in the SOC value of the power battery 3 and the charging power P3 of the power battery 3 may be as shown in table 1 below.

TABLE 1

Rate of change of SOC value of the power battery 3	A1	A2	A3	A4	A5
						Charging power of the power battery 3	B1	B2	B3	B4	B5

As can be seen from table 1 above, when the SOC value change rate of the power battery 3 is a1, the control module 101 may obtain the corresponding charging power P3 of the power battery 3 as B1; when the SOC value change rate of the power battery 3 is a2, the control module 101 may obtain that the charging power P3 of the corresponding power battery 3 is B2; when the SOC value change rate of the power battery 3 is a3, the control module 101 may obtain that the charging power P3 of the corresponding power battery 3 is B3; when the SOC value change rate of the power battery 3 is a4, the control module 101 may obtain that the charging power P3 of the corresponding power battery 3 is B4; when the SOC value change rate of the power battery 3 is a5, the control module 101 may obtain that the charging power P3 of the corresponding power battery 3 is B5.

Similarly, a second relation table between the SOC value change rate of the low-voltage battery 20 and the charging power P4 of the low-voltage battery 20 may be prestored in the control module 101, so that after the control module 101 obtains the SOC value change rate of the low-voltage battery 20, the control module can obtain the charging power P4 of the corresponding low-voltage battery 20 by comparing the second relation table. For example, a first relationship table between the rate of change in SOC value of the low-voltage battery 20 and the charging power P4 of the low-voltage battery 20 may be as shown in table 2 below.

TABLE 2

Rate of change of SOC value of low-voltage battery 20	A11	A12	A13	A14	A15
						Charging power of low-voltage battery 20	B11	B12	B13	B14	B15

As can be seen from table 2 above, when the SOC value change rate of the low-voltage battery 20 is a11, the control module 101 may obtain that the charging power P4 of the corresponding low-voltage battery 20 is B11; when the SOC value change rate of the low-voltage battery 20 is a12, the module 101 may obtain that the charging power P4 of the corresponding low-voltage battery 20 is B12; when the SOC value change rate of the low-voltage battery 20 is a13, the module 101 may obtain that the charging power P4 of the corresponding low-voltage battery 20 is B13; when the SOC value change rate of the low-voltage battery 20 is a14, the module 101 may obtain that the charging power P4 of the corresponding low-voltage battery 20 is B14; when the rate of change in the SOC value of the low-voltage battery 20 is a15, the control module 101 may acquire the corresponding charging power P4 of the low-voltage battery 20 as B15.

Specifically, after the sub-motor 5 enters the generated power regulation mode, the control module 101 may obtain the SOC value of the low-voltage battery 20, the SOC value of the power battery 3, and the vehicle required power P2 (the sum of the vehicle driving power P11 and the electrical equipment power P21), and then determine whether the SOC value of the low-voltage battery 20 is greater than a preset low battery threshold.

If the SOC value of the low-voltage battery 20 is greater than the preset low-electricity threshold, acquiring the SOC value change rate of the power battery 3, querying the charging power P3 of the power battery 3 corresponding to the SOC value change rate of the power battery 3, so as to select a proper charging power P3 to enable the SOC value of the power battery 3 to be increased, and further determining whether the charging power P3 of the power battery 3 is less than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the required power P2 of the entire vehicle, if so, that is, P3 is less than Pmin-P2, controlling the engine 1 to generate electricity with the minimum output power Pmin to adjust the power generation power of the secondary motor 5, that is, controlling the engine 1 to operate at the minimum output power Pmin corresponding to the optimal economic area; if not, namely P3 is not less than Pmin-P2, the output power of the engine 1 in the preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery 3 and the required power P2 of the whole vehicle, the engine 1 is controlled to generate power with the obtained output power to adjust the power generation power of the auxiliary motor 5, namely, the corresponding output power is searched in the preset optimal economic area of the engine 1, and the obtained output power can be the sum of the charging power P3 of the power battery 3 and the required power P2 of the whole vehicle (P2+ P3 or P11+ P21+ P3), and at the moment, the engine 1 can be controlled to generate power with the obtained output power.

If the SOC value of the low-voltage battery 20 is less than or equal to the preset low-power threshold, acquiring the SOC value change rate of the power battery 3, querying the charging power P3 of the power battery 3 corresponding to the SOC value change rate of the power battery 3, selecting a proper charging power P3 to enable the SOC value of the power battery 3 to rise, acquiring the SOC value change rate of the low-voltage battery 20, querying the charging power P4 of the low-voltage battery 20 corresponding to the SOC value change rate of the low-voltage battery 20, selecting a proper charging power P4 to enable the SOC value of the low-voltage battery 20 to rise, and further determining whether the sum of the charging power P4 of the low-voltage battery 20 and the charging power P3 of the power battery 3 is less than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine 1 and the required power P2 of the entire vehicle. If yes, namely P3+ P4 < Pmin-P2, the engine 1 is controlled to generate electricity at the minimum output power Pmin to adjust the electricity generation power of the secondary motor 5, namely the engine 1 is controlled to operate at the minimum output power Pmin corresponding to the optimal economic region, and the power battery 3 and the low-voltage storage battery 20 are charged at the power Pmin-P2 obtained by subtracting the required power P2 of the whole vehicle from the minimum output power Pmin corresponding to the optimal economic region; if not, namely P3+ P4 is not less than Pmin-P2, the output power of the engine 1 in the preset optimal economic region is obtained according to the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20 and the required power P2 of the whole vehicle, the engine 1 is controlled to generate power with the obtained output power to adjust the generating power of the auxiliary motor 5, namely the corresponding power is searched in the preset optimal economic region of the engine 1, the obtained output power is the sum of the charging power P3 of the power battery 3, the charging power P4 of the low-voltage storage battery 20 and the required power P2 of the whole vehicle (P2+ P3+ P4 or P11+ P21+ P3+ P4), and the engine 1 is controlled to generate power with the obtained output power.

From this, the engine can work in economic region when low-speed, and only generates electricity and does not participate in the drive to do not use the clutch, reduce clutch wearing and tearing or smooth mill, reduced simultaneously and suddenly frustrated and felt, improved the travelling comfort, and reduce the oil consumption, reduce the engine noise, and then maintain whole car low-speed electric balance and low-speed ride comfort, promote whole car performance.

In summary, according to the power system of the hybrid vehicle provided by the embodiment of the invention, the engine outputs power to the wheels of the hybrid vehicle through the clutch, the power motor outputs driving force to the wheels of the hybrid vehicle, the power battery supplies power to the power motor, the secondary motor realizes at least one of charging the power battery, supplying power to the power motor and supplying power to the DC-DC converter when driven by the engine to generate power, the control module obtains the SOC value of the power battery, the SOC value of the low-voltage battery and the vehicle speed of the hybrid vehicle, and controls the secondary motor to enter the generated power regulation mode according to the SOC value of the power battery and the vehicle speed of the hybrid vehicle, so that the engine operates in the preset optimal economic area, and after the secondary motor enters the generated power regulation mode, the control module is further used for regulating the generated power of the secondary motor according to the SOC value of the low-voltage battery, thereby can make the engine not participate in the drive when low-speed, and then do not use the clutch, reduce clutch wearing and tearing or smooth mill, reduced simultaneously and suddenly frustrated and felt, improved the travelling comfort to can make the engine work in economic region when low-speed, only generate electricity and do not drive, reduce the oil consumption, reduce the engine noise, maintain whole car low-speed electric balance and low-speed ride comfort, promote whole car performance.

In addition, the embodiment of the invention also provides a hybrid electric vehicle.

Fig. 8 is a block schematic diagram of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 8, the hybrid vehicle 200 includes the power system 100 of the hybrid vehicle of the embodiment described above.

According to the hybrid electric vehicle provided by the embodiment of the invention, the low-speed electric balance and the low-speed smoothness of the whole vehicle can be maintained.

Based on the hybrid electric vehicle and the power system thereof, the embodiment of the invention also provides a power generation control method of the hybrid electric vehicle.

Fig. 9 is a flowchart of a power generation control method of a hybrid vehicle according to an embodiment of the invention. As shown in fig. 9, the power generation control method of the hybrid vehicle includes the steps of:

s1: acquiring an SOC value of a power battery of the hybrid electric vehicle, a vehicle speed of the hybrid electric vehicle and an SOC value of a low-voltage storage battery of the hybrid electric vehicle;

the SOC value of the power battery and the SOC value of the low-voltage battery may be collected by a battery management system of the hybrid vehicle, so as to obtain the SOC value of the power battery and the SOC value of the low-voltage battery.

S2: controlling an auxiliary motor of the hybrid electric vehicle to enter a generated power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable an engine of the hybrid electric vehicle to operate in a preset optimal economic area, wherein the auxiliary motor is driven by the engine to generate power;

the generated power adjusting mode is a mode for adjusting the generated power of the engine, and in the generated power adjusting mode, the engine can be controlled to drive the auxiliary motor to generate power so as to adjust the generated power of the auxiliary motor.

It should also be noted that the preset optimum economy region of the engine can be determined in conjunction with the engine map. Fig. 7 shows an example of an engine universal characteristic diagram in which the side ordinate is the output torque of the engine, the abscissa is the engine speed, and the curve a is the fuel economy curve of the engine. The fuel economy curve corresponds to an optimal economy region of the engine, namely when the torque and the torque of the engine are positioned on the optimal fuel economy curve of the engine, the engine is positioned in the optimal economy region. Thus, in the embodiment of the present invention, the engine can be operated in the preset optimum economy region by controlling the engine speed and the output torque to fall on the engine fuel economy curve, such as curve a.

S3: and when the auxiliary motor enters a generated power regulation mode, regulating the generated power of the auxiliary motor according to the SOC value of the low-voltage storage battery.

Specifically, during the driving process of the hybrid electric vehicle, the engine can output power to wheels of the hybrid electric vehicle through the clutch, and the engine can also drive the auxiliary motor to generate electricity. Therefore, the output power of the engine mainly comprises two parts, one part is output to the auxiliary motor, namely the power for driving the auxiliary motor to generate electricity, and the other part is output to the wheels, namely the power for driving the wheels.

When the engine drives the auxiliary motor to generate power, the SOC value of the power battery and the speed of the hybrid electric vehicle can be firstly obtained, and then the auxiliary motor is controlled to enter a power generation power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle, so that the engine works in a preset optimal economic area. In the generated power adjusting mode, the generated power of the sub-motor can be adjusted on the premise that the engine is operated in a preset optimal economic region. And after the auxiliary motor enters a generated power regulation mode, further regulating the generated power of the auxiliary motor according to the SOC value of the low-voltage storage battery.

More specifically, in one embodiment of the present invention, the steps S2 and S3 further include controlling the generated power of the sub-motor based on the SOC value of the power battery, the SOC value of the low-voltage battery, and the vehicle speed of the hybrid vehicle, and obtaining the generated power of the engine based on the generated power of the sub-motor to control the engine to operate in a preset optimum economy zone.

Therefore, the engine can work in the preset optimal economic area, and the oil consumption of the engine in the preset optimal economic area is the lowest, the fuel economy is the highest, so that the oil consumption of the engine can be reduced, the noise of the engine is reduced, and the running economy of the whole vehicle is improved. And because the auxiliary motor has higher generating power and generating efficiency when the speed is low, thereby meeting the power consumption requirement of low-speed running, maintaining the low-speed electric balance of the whole vehicle, maintaining the low-speed ride comfort of the whole vehicle and improving the power performance of the whole vehicle. The power battery is charged, so that the power demand of the power motor and the high-voltage electrical equipment can be ensured, the normal running of the whole vehicle driven by the power motor can be ensured, the power demand of the low-voltage electrical equipment can be ensured by charging the low-voltage storage battery, the low-voltage power supply of the whole vehicle can be realized through the low-voltage storage battery when the auxiliary motor stops generating power and the power battery fails or has insufficient electric quantity, the pure fuel mode running of the whole vehicle can be ensured, and the running mileage of the whole vehicle can be improved.

Further, according to an embodiment of the present invention, when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value, if the vehicle speed of the hybrid vehicle is less than a first preset vehicle speed, the sub-motor is controlled to enter the generated power regulation mode.

The first preset value may be an upper limit value of a preset SOC value of the power battery, such as a determination value for stopping charging, and may preferably be 30%. The preset limit value may be a lower limit value of the SOC value of the power battery set in advance, for example, a determination value for stopping discharge, and may preferably be 10%. The SOC value of the power battery can be divided into three intervals, namely a first electric quantity interval, a second electric quantity interval and a third electric quantity interval, according to a first preset value and a preset limit value, when the SOC value of the power battery is smaller than or equal to the preset limit value, the SOC value of the power battery is in the first electric quantity interval, and at the moment, the power battery is only charged and is not discharged; when the SOC value of the power battery is larger than a preset limit value and is smaller than or equal to a first preset value, the SOC value of the power battery is in a second electric quantity interval, and the power battery can be actively charged when a charging requirement exists; when the SOC value of the power battery is larger than the first preset value, the SOC value of the power battery is in a third electric quantity interval, and the power battery can not be charged, namely the power battery cannot be charged actively.

Specifically, after acquiring the SOC value of the power battery and the speed of the hybrid electric vehicle, the SOC value of the power battery can be judged in an interval, if the SOC value of the power battery is in a second electric quantity interval, the SOC value of the power battery is greater than a preset limit value and is less than or equal to a first preset value, the power battery can be charged, at the moment, whether the speed of the hybrid electric vehicle is less than the first preset speed is further judged, if the speed of the hybrid electric vehicle is less than the first preset speed, the auxiliary motor is controlled to enter a generated power regulation mode, at the moment, the speed of the hybrid electric vehicle is low, the required driving force is small, the power motor is enough to drive the hybrid electric vehicle to run, and the engine can only drive the auxiliary motor to generate electricity and does not participate in driving.

Further, when the SOC value of the power battery is larger than a preset limit value and smaller than or equal to a first preset value, and the speed of the hybrid electric vehicle is smaller than a first preset speed, the required power of the hybrid electric vehicle is obtained, and when the required power of the hybrid electric vehicle is smaller than or equal to the maximum allowable power generation power of the auxiliary motor, the auxiliary motor is controlled to enter a power generation power regulation mode.

That is to say, after the SOC value of the power battery is judged to be greater than the preset limit value and less than or equal to the first preset value, and the speed of the hybrid electric vehicle is less than the first preset speed, it can be further judged whether the required power of the entire vehicle is greater than the maximum allowable power generation power of the secondary motor, if the required power of the entire vehicle is less than or equal to the maximum allowable power generation power of the secondary motor, the secondary motor is controlled to enter the power generation power adjustment mode, at this time, the required driving force of the entire vehicle is small, the required power of the entire vehicle is small, the power motor is enough to drive the hybrid electric vehicle to run, and the engine can only drive the secondary motor to.

Furthermore, when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, the speed of the hybrid electric vehicle is less than a first preset speed, and the required power of the whole vehicle is less than or equal to the maximum allowable power generation power of the auxiliary motor, the accelerator pedal depth of the hybrid electric vehicle and the whole vehicle resistance of the hybrid electric vehicle are also obtained, and when the accelerator pedal depth is less than or equal to the first preset depth and the whole vehicle resistance of the hybrid electric vehicle is less than or equal to the first preset resistance, the auxiliary motor is controlled to enter a power generation power regulation mode.

That is, after the SOC value of the power battery is judged to be greater than the preset limit value and less than or equal to the first preset value, the speed of the hybrid electric vehicle is less than the first preset speed, and the required power of the whole vehicle is less than or equal to the maximum allowable power generation power of the secondary motor, whether the depth of the accelerator pedal is greater than the first preset depth and the resistance of the whole vehicle of the hybrid electric vehicle is greater than the first preset resistance can be further judged, if the depth of the accelerator pedal is less than or equal to the first preset depth and the resistance of the whole vehicle of the hybrid electric vehicle is less than or equal to the first preset resistance, the secondary motor is controlled to enter a power generation power regulation mode, at the moment, the driving force required by the whole vehicle is less, the required power of the whole vehicle is less, the depth of the accelerator pedal is less, the resistance of the whole vehicle is less, the power, and does not participate in driving.

As described above, when the hybrid electric vehicle runs at low speed, the engine can only generate electricity and does not participate in driving, and the clutch does not need to be used because the engine does not participate in driving, so that the abrasion or the sliding wear of the clutch can be reduced, the pause and contusion feeling is reduced, the comfort is improved, moreover, the engine works in an economic area at the low speed, and because the oil consumption of the engine in a preset optimal economic area is lowest and the fuel economy is highest, the oil consumption can be reduced, the noise of the engine is reduced, the running economy of the whole vehicle is improved, the low-speed electric balance and the low-speed smoothness of the whole vehicle are maintained, and the performance of the whole vehicle is improved.

According to an embodiment of the present invention, when the engine is controlled to drive the auxiliary motor to generate power by itself and the power motor is controlled to output driving force by itself, the generated power of the engine can be obtained according to the following formula:

P0＝P1/η/ζ

where P0 is the generated power of the engine, P1 is the generated power of the sub-motor, η belt transmission efficiency, and ζ is the efficiency of the sub-motor.

That is, in the case where the engine can generate only power without participating in driving, the generated power P0 of the engine can be calculated from the generated power of the sub-motor, the belt transmission efficiency η, and the efficiency ζ of the sub-motor, and the engine can be controlled to drive the sub-motor to generate power with the generated power P0 obtained to control the generated power of the sub-motor.

In addition, according to an embodiment of the present invention, when the SOC value of the power battery is less than a preset limit value, or the vehicle speed of the hybrid vehicle is greater than or equal to a first preset vehicle speed, or the power required by the vehicle is greater than the maximum allowable power generation power of the auxiliary motor, or the depth of the accelerator pedal is greater than a first preset depth, or the vehicle resistance of the hybrid vehicle is greater than a first preset resistance, the engine is controlled to participate in driving.

That is to say, when the SOC value of the power battery is less than a preset limit value, or the vehicle speed of the hybrid vehicle is greater than or equal to a first preset vehicle speed, or the power demanded of the entire vehicle is greater than the maximum allowable power generation of the auxiliary motor, or the depth of the accelerator pedal is greater than a first preset depth, or the resistance of the entire vehicle of the hybrid vehicle is greater than a first preset resistance, the control module controls the engine to participate in driving, at this time, the power battery is not discharged, the driving force required by the entire vehicle is large, the power demanded of the entire vehicle is large, the depth of the accelerator pedal is large, or the resistance of the entire vehicle is large, the power motor is not enough to drive the hybrid vehicle, and the.

Therefore, the engine can participate in driving when the driving force output by the power motor is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved.

More specifically, when the power required by the entire vehicle is larger than the maximum allowable generated power of the auxiliary motor, the engine is also controlled to participate in driving so that the engine outputs power to the wheels of the hybrid vehicle through the clutch.

When the SOC value of the power battery is smaller than or equal to a preset limit value, the engine is also controlled to participate in driving so that the engine outputs power to wheels of the hybrid electric vehicle through the clutch; when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the depth of an accelerator pedal is larger than a first preset depth, the engine is also controlled to participate in driving so that the engine outputs power to wheels through a clutch; when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than the first preset speed, and the overall resistance of the hybrid electric vehicle is larger than the first preset resistance, the engine is controlled to participate in driving so that the engine outputs power to wheels through the clutch.

That is to say, the SOC value of the power battery, the accelerator pedal depth of the hybrid electric vehicle, the vehicle speed, the vehicle resistance and the vehicle required power can be obtained in real time, and the SOC value of the power battery, the accelerator pedal depth of the hybrid electric vehicle, the vehicle speed and the vehicle resistance are judged:

firstly, when the SOC value of the power battery is smaller than a preset limit value, the power battery cannot provide enough electric energy due to the fact that the electric quantity of the power battery is too low, the engine and the power motor are controlled to participate in driving at the same time, the engine can be controlled to drive the auxiliary motor to generate electricity to charge the power battery, the engine can be controlled to drive the auxiliary motor to generate electricity at the moment, and the engine can work in a preset optimal economic area by adjusting the generated power of the auxiliary motor.

Secondly, when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the depth of the accelerator pedal is larger than a first preset depth, the control module controls the engine and the power motor to participate in driving at the same time because the depth of the accelerator pedal is deeper, the engine can be controlled to drive the auxiliary motor to generate electricity, and the engine can work in a preset optimal economic area by adjusting the power generation power of the auxiliary motor.

And thirdly, when the SOC value of the power battery is less than or equal to a first preset value, the speed of the hybrid electric vehicle is less than a first preset speed, and the whole vehicle resistance of the hybrid electric vehicle is greater than the first preset resistance, the engine and the power motor can be controlled to simultaneously participate in driving due to the fact that the whole vehicle resistance is large, the engine can be controlled to drive the auxiliary motor to generate electricity, and the engine can work in a preset optimal economic area by adjusting the power generation power of the auxiliary motor.

Therefore, the engine can participate in driving when the driving force output by the power motor is insufficient, so that the normal running of the whole vehicle is ensured, the power performance of the whole vehicle is improved, and the running mileage of the whole vehicle is improved. And moreover, the engine can be controlled to work in an economic area, and the oil consumption of the engine 1 in a preset optimal economic area is the lowest, and the fuel economy is the highest, so that the oil consumption can be reduced, the noise of the engine is reduced, and the economic performance of the whole vehicle is improved.

In addition, the control module is further configured to: and when the SOC value of the power battery is less than or equal to a preset limit value and the speed of the hybrid electric vehicle is greater than a first preset speed, controlling the engine to participate in driving so that the engine outputs power to wheels through the clutch.

Of course, it should be understood that the control module is also operable to: when the SOC value of the power battery is larger than the first preset value, the engine does not drive the auxiliary motor to generate electricity, the electric quantity of the power battery is close to full electricity at the moment, charging is not needed, and the engine does not drive the auxiliary motor to generate electricity. That is, when the electric quantity of the power battery is close to full charge, the engine does not drive the auxiliary motor to generate electricity, so that the auxiliary motor does not charge the power battery.

Further, after the sub-motor enters the electric power adjustment mode, the generated power of the sub-motor may be adjusted, and the generated power adjustment process according to the embodiment of the present invention is described in detail below.

According to one embodiment of the invention, after the auxiliary motor enters the generated power regulation mode, the generated power of the auxiliary motor is regulated according to the vehicle required power of the hybrid electric vehicle, the charging power of the power battery, the charging power of the low-voltage storage battery and the SOC value of the low-voltage storage battery.

Specifically, the formula for adjusting the generated power of the sub-motor according to the vehicle demand power of the hybrid vehicle, the charging power of the power battery, and the charging power of the low-voltage battery is as follows:

P1-P2 + P3+ P4, wherein P2-P11 + P21,

p1 is the generated power of the auxiliary motor, P2 is the required power of the whole vehicle, P3 is the charging power of the power battery, P4 is the charging power of the low-voltage storage battery, P11 is the driving power of the whole vehicle, and P21 is the power of the electrical equipment.

It should be noted that the electrical devices include a first electrical device and a second electrical device, that is, the electrical device power P21 may include power required by a high-voltage electrical device and a low-voltage electrical device.

It should be further noted that the vehicle driving power P11 may include the output power of the power motor, and the vehicle driving power P11 may be obtained according to a preset throttle-torque curve of the power motor and the rotation speed of the power motor, where the preset throttle-torque curve may be determined when the hybrid vehicle is power-matched; the power P21 of the electric equipment can be obtained in real time according to the electric equipment operated by the whole vehicle, for example, the power P21 of the electric equipment is calculated through DC consumption on a bus; the charging power P3 of the power battery can be obtained according to the SOC value of the power battery, and the charging power P4 of the low-voltage storage battery can be obtained according to the SOC value of the low-voltage storage battery.

Specifically, during the driving of the hybrid vehicle, the charging power P3 of the power battery, the charging power P4 of the low-voltage battery, the vehicle driving power P11 and the electrical equipment power P21 are obtained, and the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage battery, the vehicle driving power P11 and the electrical equipment power P21 is used as the power generation power P1 of the auxiliary motor, so that the power generation power of the auxiliary motor can be adjusted according to the calculated P1 value, for example, the output torque and the rotating speed of the engine can be controlled according to the calculated P1 value, so as to adjust the power generated by the auxiliary motor of the engine.

Further, according to an embodiment of the present invention, the adjusting of the generated power of the sub motor includes: and acquiring the SOC value change rate of the power battery, and regulating the generating power of the secondary motor according to the relation between the required power of the whole vehicle and the minimum output power corresponding to the optimal economic area of the engine, the SOC value change rate of the power battery, the SOC value of the low-voltage storage battery and the SOC value change rate of the low-voltage storage battery.

It should be understood that the rate of change of the SOC-value of the power battery may be obtained from the SOC-value of the power battery, for example, the SOC-value of the power battery is collected once every time interval t, so that the ratio of the difference between the current SOC-value and the previous SOC-value of the power battery to the time interval t may be used as the rate of change of the SOC-value of the power battery. Similarly, the SOC-value change rate of the low-voltage battery may be obtained from the SOC value of the low-voltage battery, for example, the SOC value of the low-voltage battery may be collected once per time interval t, so that the ratio of the difference between the current SOC value and the previous SOC value of the low-voltage battery to the time interval t may be taken as the SOC-value change rate of the low-voltage battery.

Specifically, the optimal economic region of the engine may be determined according to the engine universal characteristic curve shown in fig. 7, the minimum output power corresponding to the optimal economic region of the engine may be further obtained, and after the minimum output power corresponding to the optimal economic region of the engine is determined, the power generation power of the sub-motor may be adjusted according to the relationship between the total vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic region of the engine, the SOC value change rate of the power battery, the SOC value of the low-voltage battery, and the SOC value change rate of the low-voltage battery.

Therefore, when the hybrid electric vehicle runs at a low speed, the engine works in an economic area, the oil consumption can be reduced, the noise of the engine is reduced, the economic performance of the whole vehicle is improved, the engine can only generate electricity and does not participate in driving at the low speed, and the clutch does not need to be used because the engine does not participate in driving, so that the abrasion or the sliding wear of the clutch can be reduced, the pause and contusion can be reduced, the comfort is improved, the low-speed electric balance and the low-speed ride comfort of the whole vehicle are maintained, and the performance of the whole vehicle is improved.

The specific control manner for adjusting the generated power of the sub-motor according to the relationship between the vehicle required power P2 and the minimum output power Pmin corresponding to the optimal economic zone of the engine, the rate of change of the SOC value of the power battery, the SOC value of the low-voltage battery, and the rate of change of the SOC value of the low-voltage battery after the sub-motor 5 enters the generated power adjustment mode will be further described below.

Specifically, when the SOC value of the low-voltage storage battery is larger than a preset low-electricity threshold, acquiring the charging power of the power battery according to the SOC value change rate of the power battery, and judging whether the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, wherein if the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the engine is controlled to generate electricity with the minimum output power so as to adjust the power generation power of the secondary motor; if the charging power of the power battery is larger than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the output power of the engine in the preset optimal economic area is obtained according to the sum of the charging power of the power battery and the required power of the whole vehicle, and the engine is controlled to generate electricity according to the obtained output power so as to adjust the power generation power of the auxiliary motor.

Specifically, when the SOC value of the low-voltage storage battery is less than or equal to a preset low-battery threshold value, the SOC value change rate of the low-voltage storage battery and the SOC value change rate of the power battery are acquired, and obtains the charging power of the low-voltage storage battery according to the SOC value change rate of the low-voltage storage battery and obtains the charging power of the power battery according to the SOC value change rate of the power battery, and judging whether the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, wherein, if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is less than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the engine is controlled to generate electricity with the minimum output power so as to adjust the generated power of the auxiliary motor; if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is larger than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the output power of the engine in the preset optimal economic area is obtained according to the sum of the charging power of the power battery, the charging power of the low-voltage storage battery and the required power of the whole vehicle, and the engine is controlled to generate electricity with the obtained output power so as to adjust the power generation power of the auxiliary motor.

It should be noted that, the control module may pre-store a first relationship table between the SOC value change rate of the power battery and the charging power P3 of the power battery, so that after the SOC value change rate of the power battery is obtained, the charging power P3 of the corresponding power battery can be obtained by comparing the first relationship table. For example, a first relationship table between the rate of change of the SOC value of the power battery and the charging power P3 of the power battery may be as shown in table 1 below.

TABLE 1

SOC value change rate of power battery	A1	A2	A3	A4	A5
						Charging power of power battery	B1	B2	B3	B4	B5

As can be seen from table 1 above, when the SOC value change rate of the power battery is a1, the charging power P3 of the corresponding power battery is B1; when the SOC value change rate of the power battery is A2, the charging power P3 of the corresponding power battery can be obtained as B2; when the SOC value change rate of the power battery is A3, the charging power P3 of the corresponding power battery can be obtained as B3; when the SOC value change rate of the power battery is A4, the charging power P3 of the corresponding power battery can be obtained as B4; when the change rate of the SOC value of the power battery is A5, the charging power P3 of the corresponding power battery can be obtained as B5.

Similarly, a second relation table between the SOC value change rate of the low-voltage battery and the charging power P4 of the low-voltage battery may be prestored in the control module, and thus, after the SOC value change rate of the low-voltage battery is obtained, the charging power P4 of the corresponding low-voltage battery may be obtained by comparing the second relation table. For example, a first relationship table between the rate of change in SOC value of the low-voltage battery and the charging power P4 of the low-voltage battery may be as shown in table 2 below.

TABLE 2

Rate of change of SOC value of low-voltage battery	A11	A12	A13	A14	A15
						Charging power of low-voltage battery	B11	B12	B13	B14	B15

As can be seen from table 2 above, when the SOC value change rate of the low-voltage battery is a11, the charging power P4 of the corresponding low-voltage battery is B11; when the SOC value change rate of the low-voltage storage battery is A12, the charging power P4 of the corresponding low-voltage storage battery can be acquired as B12; when the SOC value change rate of the low-voltage storage battery is A13, the charging power P4 of the corresponding low-voltage storage battery can be acquired as B13; when the SOC value change rate of the low-voltage storage battery is A14, the charging power P4 of the corresponding low-voltage storage battery can be acquired as B14; when the rate of change in the SOC value of the low-voltage battery is a15, the corresponding charging power P4 of the low-voltage battery may be obtained as B15.

Specifically, after the sub-battery 5 enters the electric power regulation mode, the SOC value of the low-voltage battery, the SOC value of the power battery, and the vehicle required power P2 (the sum of the vehicle driving power P11 and the electrical equipment power P21) may be obtained, and then it is determined whether the SOC value of the low-voltage battery is greater than a preset low battery threshold value.

If the SOC value of the low-voltage storage battery is larger than a preset low-battery threshold value, acquiring the change rate of the SOC value of the power battery, and inquiring the charging power P3 of the power battery corresponding to the SOC value change rate of the power battery, so as to select proper charging power P3 to enable the SOC value of the power battery to be increased, and further judge whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the required power P2 of the whole vehicle, if so, namely P3 < Pmin-P2, the power generation of the auxiliary motor is adjusted by controlling the engine to generate the minimum output power Pmin, controlling the engine to operate at the minimum output power Pmin corresponding to the optimal economic area, and charging the power battery by subtracting the power P2 required by the whole vehicle from the minimum output power Pmin corresponding to the optimal economic area, namely Pmin-P2; if not, namely P3 is not less than Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, the engine is controlled to generate power to adjust the power generation power of the auxiliary motor, namely the corresponding output power is searched in the preset optimal economic area of the engine, the obtained output power can be the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle (P2+ P3 or P11+ P21+ P3), and the engine is controlled to generate power according to the obtained output power.

If the SOC value of the low-voltage storage battery is smaller than or equal to the preset low-electricity threshold, acquiring the SOC value change rate of the power battery, inquiring the charging power P3 of the power battery corresponding to the SOC value change rate of the power battery, selecting a proper charging power P3 to enable the SOC value of the power battery to be increased, acquiring the SOC value change rate of the low-voltage storage battery, inquiring the charging power P4 of the low-voltage storage battery corresponding to the SOC value change rate of the low-voltage storage battery, selecting a proper charging power P4 to enable the SOC value of the low-voltage storage battery to be increased, and further judging whether the sum of the charging power P4 of the low-voltage storage battery and the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the required power P2 of the. If yes, namely P3+ P4 < Pmin-P2, the engine is controlled to generate electricity at the minimum output power Pmin to adjust the electricity generation power of the auxiliary motor, namely the engine is controlled to operate at the minimum output power Pmin corresponding to the optimal economic area, and the power battery and the low-voltage storage battery are charged at the power Pmin-P2 obtained by subtracting the required power P2 of the whole vehicle from the minimum output power Pmin corresponding to the optimal economic area; if not, namely P3+ P4 is not less than Pmin-P2, the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, the engine is controlled to generate power with the obtained output power to adjust the generating power of the auxiliary motor, namely the corresponding output power is searched in the preset optimal economic area of the engine, the obtained output power can be the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle (P2+ P3+ P4 or P11+ P21+ P3+ P4), and the engine is controlled to generate power with the obtained output power.

As described above, as shown in fig. 10, the power generation control method of the hybrid vehicle according to the embodiment of the present invention includes the steps of:

s601: and acquiring the SOC value M of the power battery and the speed V of the hybrid electric vehicle.

S602: and judging whether the vehicle speed V of the hybrid electric vehicle is less than a first preset vehicle speed V1.

If yes, go to step S603; if not, step S604 is performed.

S603: and judging whether the SOC value M of the power battery is less than or equal to a first preset value M1.

If yes, go to step S607; if not, step S606 is performed.

S604: and judging whether the SOC value M of the power battery is less than or equal to a first preset value M1.

If yes, go to step S605; if not, step S606 is performed.

S605: and controlling the engine to participate in driving.

S606: the engine is controlled not to drive the auxiliary motor to generate electricity.

S607: and acquiring the depth D of an accelerator pedal of the hybrid electric vehicle and the overall vehicle resistance F of the hybrid electric vehicle.

S608: and judging whether the depth D of the accelerator pedal is greater than a first preset depth D1 or whether the overall vehicle resistance F of the hybrid vehicle is greater than a first preset resistance F1 or whether the SOC value M of the power battery is less than a preset limit value M2.

If yes, go to step S605; if not, step S609 is performed.

S609: and acquiring the total vehicle required power P2 of the hybrid electric vehicle.

S610: and judging whether the required power P2 of the whole vehicle is less than or equal to the maximum allowable power Pmax of the auxiliary motor.

If yes, go to step S611; if not, step S605 is performed.

S611: the engine is controlled to drive the auxiliary motor to generate power, and the engine does not participate in driving. At this time, the sub-motor is controlled to enter the generated power adjustment mode.

S612: and judging whether the SOC value of the low-voltage storage battery is less than or equal to a preset low-power threshold value or not.

If so, go to step S617; if not, step S613 is executed.

S613: and acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery.

S614: and judging whether the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the required power P2 of the whole vehicle.

If yes, go to step S615; if not, step S616 is performed.

S615: the engine is controlled to generate power at the minimum output power Pmin to adjust the generated power of the auxiliary motor.

S616: and acquiring the output power of the engine in a preset optimal economic area according to the sum of the charging power P3 of the power battery and the required power P2 of the whole vehicle, and controlling the engine to generate power with the acquired output power so as to regulate the generated power of the auxiliary motor.

S617: the charging power P4 of the low-voltage battery is obtained from the rate of change of the SOC value of the low-voltage battery.

S618: and acquiring the charging power P3 of the power battery according to the SOC value change rate of the power battery.

S619: and judging whether the sum of the charging power P4 of the low-voltage storage battery and the charging power P3 of the power battery is smaller than the difference between the minimum output power Pmin corresponding to the optimal economic area of the engine and the required power P2 of the whole vehicle.

If yes, go to step S620; if not, step S621 is performed.

S620: the engine is controlled to generate power at the minimum output power Pmin to adjust the generated power of the auxiliary motor.

S621: the output power of the engine in a preset optimal economic area is obtained according to the sum of the charging power P3 of the power battery, the charging power P4 of the low-voltage storage battery and the required power P2 of the whole vehicle, and the generated power of the auxiliary motor is adjusted by controlling the engine to generate power with the obtained output power.

In summary, according to the power generation control method of the hybrid electric vehicle provided by the embodiment of the invention, the SOC value of the power battery, the SOC value of the low-voltage battery and the vehicle speed of the hybrid electric vehicle are obtained, the secondary motor is controlled to enter the power generation power regulation mode according to the SOC value of the power battery and the vehicle speed of the hybrid electric vehicle, so that the engine operates in the preset optimal economic region, and after the secondary motor enters the power generation power regulation mode, the power generation power of the secondary motor is regulated according to the SOC value of the low-voltage battery, so that the engine does not participate in driving at low speed, a clutch is not used, clutch abrasion or sliding wear is reduced, meanwhile, the suspension feeling is reduced, the comfort is improved, and the engine can operate in the economic region at low speed, only power generation is not performed, the oil consumption is reduced, the noise of the engine is reduced, the low-speed electrical balance and low-ride comfort of the, and the performance of the whole vehicle is improved.

Finally, an embodiment of the present invention also provides a computer-readable storage medium having instructions stored therein, which when executed, the hybrid vehicle executes the power generation control method of the above embodiment.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A power system of a hybrid vehicle, characterized by comprising:

an engine that outputs power to wheels of the hybrid vehicle through a clutch;

a power motor for outputting a driving force to wheels of the hybrid vehicle;

the power battery is used for supplying power to the power motor;

a DC-DC converter;

the low-voltage storage battery is connected with the DC-DC converter;

the auxiliary motor is connected with the engine, the auxiliary motor is respectively connected with the power motor, the DC-DC converter and the power battery, and the auxiliary motor is driven by the engine to generate electricity;

the control module is used for acquiring the SOC value of the power battery, the SOC value of the low-voltage storage battery and the speed of the hybrid electric vehicle, and controlling the secondary motor to enter a power generation power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable the engine to operate in a preset optimal economic area, wherein after the secondary motor enters the power generation power regulation mode, the control module is further used for regulating the power generation power of the secondary motor according to the SOC value of the low-voltage storage battery;

the control module is further configured to: and when the auxiliary motor enters the generated power regulation mode, regulating the generated power of the auxiliary motor according to the finished automobile required power of the hybrid electric vehicle, the charging power of the power battery, the charging power of the low-voltage storage battery and the SOC value of the low-voltage storage battery.

2. The hybrid vehicle powertrain system of claim 1, wherein the control module is configured to: and when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, if the speed of the hybrid electric vehicle is less than a first preset speed, controlling the auxiliary motor to enter the generated power regulation mode.

3. The hybrid vehicle powertrain of claim 2, wherein the control module is further configured to: when the SOC value of the power battery is larger than a preset limit value and smaller than or equal to a first preset value and the speed of the hybrid electric vehicle is smaller than a first preset speed, acquiring the required power of the whole hybrid electric vehicle, and when the required power of the whole hybrid electric vehicle is smaller than or equal to the maximum allowable generating power of the auxiliary motor, controlling the auxiliary motor to enter a generating power regulation mode.

4. The hybrid vehicle powertrain of claim 3, wherein the control module is further configured to: when the SOC value of the power battery is larger than a preset limit value and smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, the required power of the whole vehicle is smaller than or equal to the maximum allowable power generation power of the auxiliary motor, the accelerator pedal depth of the hybrid electric vehicle and the whole vehicle resistance of the hybrid electric vehicle are obtained, the accelerator pedal depth is smaller than or equal to the first preset depth, the whole vehicle resistance of the hybrid electric vehicle is smaller than or equal to the first preset resistance, and the auxiliary motor is controlled to enter the power generation regulation mode.

5. The power system of a hybrid vehicle according to claim 4, wherein the formula for adjusting the generated power of the secondary motor according to the total vehicle required power of the hybrid vehicle, the charging power of the power battery, and the charging power of the low-voltage storage battery is as follows:

P1-P2 + P3+ P4, wherein P2-P11 + P21,

6. The hybrid vehicle powertrain of claim 5, wherein the control module is further configured to: and acquiring the SOC value change rate of the power battery, and adjusting the generating power of the secondary motor according to the relation between the required power of the whole vehicle and the minimum output power corresponding to the optimal economic area of the engine, the SOC value change rate of the power battery, the SOC value of the low-voltage storage battery and the SOC value change rate of the low-voltage storage battery.

7. The hybrid vehicle powertrain of claim 6, wherein the control module is further configured to: when the SOC value of the low-voltage storage battery is larger than a preset low-electricity threshold, acquiring the charging power of the power battery according to the SOC value change rate of the power battery, and judging whether the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, wherein,

if the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the engine is controlled to generate electricity with the minimum output power so as to adjust the generating power of the auxiliary motor;

and if the charging power of the power battery is larger than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, acquiring the output power of the engine in the preset optimal economic area according to the sum of the charging power of the power battery and the required power of the whole vehicle, and controlling the engine to generate electricity with the acquired output power to adjust the power generation power of the auxiliary motor.

8. The hybrid vehicle powertrain of claim 6, wherein the control module is further configured to: when the SOC value of the low-voltage storage battery is smaller than or equal to a preset low-electricity threshold, acquiring the SOC value change rate of the low-voltage storage battery and the SOC value change rate of the power battery, acquiring the charging power of the low-voltage storage battery according to the SOC value change rate of the low-voltage storage battery and the charging power of the power battery according to the SOC value change rate of the power battery, and judging whether the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, wherein,

if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the engine is controlled to generate electricity with the minimum output power so as to adjust the generating power of the auxiliary motor;

if the sum of the charging power of the low-voltage storage battery and the charging power of the power battery is larger than or equal to the difference between the minimum output power corresponding to the optimal economic area of the engine and the required power of the whole vehicle, the output power of the engine in the preset optimal economic area is obtained according to the sum of the charging power of the power battery, the charging power of the low-voltage storage battery and the required power of the whole vehicle, and the engine is controlled to generate electricity with the obtained output power so as to adjust the power generation power of the auxiliary motor.

9. The hybrid vehicle powertrain of claim 6, wherein the control module is further configured to: and when the required power of the whole vehicle is greater than the maximum allowable power generation power of the auxiliary motor, controlling the engine to participate in driving so that the engine outputs power to the wheels through the clutch.

10. The hybrid vehicle powertrain of claim 4, wherein the control module is further configured to: when the SOC value of the power battery is smaller than or equal to a preset limit value, controlling the engine to participate in driving so that the engine outputs power to the wheels through the clutch;

when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the depth of the accelerator pedal is larger than a first preset depth, the engine is controlled to participate in driving so that the engine outputs power to the wheels through the clutch;

when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the overall resistance of the hybrid electric vehicle is larger than the first preset resistance, the engine participates in driving so that the engine outputs power to the wheels through the clutch.

11. A hybrid vehicle characterized by comprising the power system of the hybrid vehicle according to any one of claims 1 to 10.

12. A power generation control method for a hybrid vehicle, characterized by comprising the steps of:

acquiring an SOC value of a power battery of the hybrid electric vehicle, a vehicle speed of the hybrid electric vehicle and an SOC value of a low-voltage storage battery of the hybrid electric vehicle;

controlling an auxiliary motor of the hybrid electric vehicle to enter a generated power regulation mode according to the SOC value of the power battery and the speed of the hybrid electric vehicle so as to enable an engine of the hybrid electric vehicle to operate in a preset optimal economic area, wherein the auxiliary motor is driven by the engine to generate power;

when the auxiliary motor enters a generated power regulation mode, regulating the generated power of the auxiliary motor according to the SOC value of the low-voltage storage battery;

and when the auxiliary motor enters the generated power regulation mode, regulating the generated power of the auxiliary motor according to the finished automobile required power of the hybrid electric vehicle, the charging power of the power battery, the charging power of the low-voltage storage battery and the SOC value of the low-voltage storage battery.

13. The power generation control method of the hybrid vehicle according to claim 12, wherein when the SOC value of the power battery is greater than a preset limit value and equal to or less than a first preset value, the sub-motor is controlled to enter the generated power adjustment mode if the vehicle speed of the hybrid vehicle is less than a first preset vehicle speed.

14. The power generation control method of the hybrid vehicle according to claim 13, characterized in that when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value and the vehicle speed of the hybrid vehicle is less than a first preset vehicle speed, the total vehicle required power of the hybrid vehicle is also acquired, and when the total vehicle required power is less than or equal to the maximum allowable generated power of the secondary motor, the secondary motor is controlled to enter the generated power adjustment mode.

15. The power generation control method of the hybrid electric vehicle according to claim 14, wherein when the SOC value of the power battery is greater than a preset limit value and less than or equal to a first preset value, the vehicle speed of the hybrid electric vehicle is less than a first preset vehicle speed, and the vehicle demand power is less than or equal to the maximum allowable power generation power of the secondary motor, the accelerator pedal depth of the hybrid electric vehicle and the vehicle resistance of the hybrid electric vehicle are further acquired, and when the accelerator pedal depth is less than or equal to the first preset depth and the vehicle resistance of the hybrid electric vehicle is less than or equal to the first preset resistance, the secondary motor is controlled to enter the power generation adjustment mode.

16. The power generation control method of the hybrid vehicle according to claim 15, wherein the formula for adjusting the generated power of the sub-motor based on the total vehicle required power of the hybrid vehicle, the charged power of the power battery, and the charged power of the low-voltage storage battery is as follows:

P1-P2 + P3+ P4, wherein P2-P11 + P21,

17. The power generation control method for a hybrid vehicle according to claim 16, wherein the adjusting of the generated power of the sub-motor includes:

and acquiring the SOC value change rate of the power battery, and adjusting the generating power of the secondary motor according to the relation between the required power of the whole vehicle and the minimum output power corresponding to the optimal economic area of the engine, the SOC value change rate of the power battery, the SOC value of the low-voltage storage battery and the SOC value change rate of the low-voltage storage battery.

18. The power generation control method of a hybrid vehicle according to claim 17, wherein when the SOC value of the low-voltage battery is greater than a preset low battery threshold, the charging power of the power battery is obtained according to the rate of change of the SOC value of the power battery, and it is determined whether the charging power of the power battery is less than the difference between the minimum output power corresponding to the optimal economic zone of the engine and the required power of the entire vehicle, wherein,

19. The power generation control method of a hybrid vehicle according to claim 17, wherein when the SOC value of the low-voltage secondary battery is equal to or less than a preset low battery threshold value, the SOC value change rate of the low-voltage secondary battery and the SOC value change rate of the power battery are acquired, the charging power of the low-voltage secondary battery is acquired according to the SOC value change rate of the low-voltage secondary battery and the charging power of the power battery is acquired according to the SOC value change rate of the power battery, and it is determined whether the sum of the charging power of the low-voltage secondary battery and the charging power of the power battery is smaller than the difference between the minimum output power corresponding to the optimal economic zone of the engine and the required power of the entire vehicle, wherein,

20. The power generation control method of the hybrid vehicle according to claim 17, characterized in that when the vehicle required power is larger than the maximum allowable power generation power of the secondary motor, the engine is also controlled to participate in driving so that the engine outputs power to wheels of the hybrid vehicle through a clutch.

21. The power generation control method of a hybrid vehicle according to claim 15, wherein,

when the SOC value of the power battery is smaller than or equal to a preset limit value, the engine is also controlled to participate in driving so that the engine outputs power to wheels of the hybrid electric vehicle through a clutch;

when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the depth of the accelerator pedal is larger than a first preset depth, the engine is also controlled to participate in driving so that the engine outputs power to the wheels through the clutch;

when the SOC value of the power battery is smaller than or equal to a first preset value, the speed of the hybrid electric vehicle is smaller than a first preset speed, and the overall resistance of the hybrid electric vehicle is larger than a first preset resistance, the engine is also controlled to participate in driving so that the engine outputs power to the wheels through the clutch.

22. A computer-readable storage medium having instructions stored therein, which when executed, the hybrid vehicle executes the power generation control method according to any one of claims 12 to 21.