CN114987223A

CN114987223A - Pure electric vehicle launch start control method and control system

Info

Publication number: CN114987223A
Application number: CN202210749223.2A
Authority: CN
Inventors: 袁舟力; 陈坤; 方程; 黄敏
Original assignee: Lantu Automobile Technology Co Ltd
Current assignee: Lantu Automobile Technology Co Ltd
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2022-09-02

Abstract

The invention provides a pure electric vehicle launch start control method and a control system, wherein the control method comprises the following steps: when the pure electric vehicle is in the launch starting mode, the loss and heat productivity of the motor controller are inhibited by reducing the carrier frequency of the motor body and the motor controller; and/or when the pure electric vehicle is in an ejection starting mode, driving a motor rotor to rotate by a specific angle so as to reduce motor rotor-locked phase current; and/or when the pure electric vehicle is in the launch starting mode, the flow of the cooling liquid flowing through the motor controller and the motor body is increased, and the temperature of the cooling liquid is reduced, so that the heat dissipation of the motor body and the motor controller is enhanced. The invention starts from two directions of inhibiting heating and enhancing heat dissipation, and aims to reduce the motor locked-rotor damage risk in the catapult starting torque holding stage of the pure electric vehicle.

Description

Pure electric vehicle launch start control method and control system

Technical Field

The invention relates to the field of control of pure electric vehicles, in particular to a control method and a control system for catapulting starting of a pure electric vehicle.

Background

The principle of the launch starting is that the rotating speed of the engine is adjusted to the output state of the maximum torque by using the gearbox, so that the engine starts to output the maximum torque at the moment of starting, and the optimal acceleration is realized. The electric vehicle is similar to the fuel vehicle in realization method, and the torque output is changed into a driving motor from an engine.

The existing control methods for launch starting mainly comprise two types, wherein the first type comprises the following implementation steps:

1. shut down the ESP stabilization system (manually if necessary);

2. the brake is treaded to be dead to reach a preset stroke;

3. the accelerator is pedaled to be dead to reach a preset stroke;

4. and (5) lifting the brake at the moment when the rotating speed rises to the optimal starting rotating speed.

The control method describes the implementation process of the launch starting function, but the motor stalling process and the control method are not described in more detail.

The second launch starting is realized by adopting a virtual motor position signal as the input of the motor controller once the motor controller judges that the permanent magnet synchronous motor is in a locked-rotor working condition, so that the motor controller outputs sinusoidal current to the permanent magnet synchronous motor; and giving up the virtual motor position signal as the input of the motor controller until the motor controller judges that the permanent magnet synchronous motor is no longer in the locked-rotor working condition.

This kind of mode has realized the normal output of moment of torsion when the motor stalls, and has reduced the generating heat of motor to a certain extent, but does not match completely with the launch starting function, needs longer check-out time, has increased and generates heat, and this method itself does not design for reducing completely and generates heat, and the control to stalling temperature rise has the promotion space yet.

Disclosure of Invention

The invention provides a pure electric vehicle launch starting control method and a pure electric vehicle launch starting control system, aiming at the technical problems in the prior art.

According to a first aspect of the invention, a pure electric vehicle launch starting control method is provided, which comprises the following steps:

when the pure electric vehicle is in the launch starting mode, the loss and heat productivity of the motor controller are inhibited by reducing the carrier frequency of the motor body and the motor controller; and/or the presence of a gas in the gas,

when the pure electric vehicle is in an ejection starting mode, driving a motor rotor to rotate by a specific angle so as to reduce motor rotor blocking current; and/or the presence of a gas in the gas,

when the pure electric vehicle is in the launch starting mode, the flow of the cooling liquid flowing through the motor controller and the motor body is increased, the temperature of the cooling liquid is reduced, and the heat dissipation of the motor body and the motor controller is enhanced.

On the basis of the technical scheme, the invention can be improved as follows.

Optionally, whether the pure electric vehicle is in the launch starting mode is judged in the following manner:

acquiring a launch starting state position of the pure electric vehicle;

and judging whether the pure electric vehicle is in the launch starting mode or not according to the launch starting state bit of the pure electric vehicle.

Optionally, when pure electric vehicles is in the launch starting mode, through reducing the carrier frequency of motor body and motor controller to restrain motor controller's loss calorific capacity, include:

when the pure electric vehicle is in a launch starting mode, searching a first carrier frequency corresponding to the current vehicle speed in a carrier frequency table according to the current vehicle speed of the pure electric vehicle, wherein the carrier frequency table stores the corresponding relation between the vehicle speed and the carrier frequency;

and taking a second carrier frequency obtained by subtracting a set frequency from the first carrier frequency as the reduced carrier frequency, wherein the set frequency is related to the current speed of the pure electric vehicle.

Optionally, the carrier frequency table stores a corresponding relationship between a vehicle speed range and a carrier frequency;

according to the current speed of the pure electric vehicle, a first carrier frequency corresponding to the current speed of the pure electric vehicle is searched in the carrier frequency table, and the method comprises the following steps:

acquiring a vehicle speed range in which the current vehicle speed of the pure electric vehicle falls;

and searching a corresponding first carrier frequency in the carrier frequency table based on the vehicle speed range.

Optionally, when the pure electric vehicle is in the launch starting mode, the rotor of the drive motor rotates by a specific angle to reduce the phase current of the motor locked rotor, including:

determining a locked rotor test point position with minimum temperature rise on a motor stator winding;

and determining a specific angle at which the motor rotor needs to be driven to rotate based on the zero position of the motor and the locked rotor test point position of the minimum temperature rise, and driving the motor rotor to rotate to the specific position in the launch starting mode.

Optionally, determining a locked rotor test point position of the minimum temperature rise on the motor stator winding includes:

evenly select n stall test point positions along motor stator winding circumferencial direction to test the temperature rise of each stall test point position department, determine the stall test point position of minimum temperature rise.

Optionally, when pure electric vehicles is in the launch starting mode, the coolant flow of motor controller and the motor body is flowed through in the increase to reduce coolant temperature, with the heat dissipation of reinforcing motor body and motor controller, include:

when the pure electric vehicle is in the launch starting mode, the VCU of the vehicle control unit outputs a PWM wave control signal with an increased duty ratio to drive the water pump and the cooling fan to operate, so that the rotating speeds of the water pump and the cooling fan are increased, the flow of cooling liquid flowing through the motor controller and the motor body is increased, and the temperature of the cooling liquid is reduced.

According to a second aspect of the invention, a pure electric vehicle launch start control system is provided, which comprises: the first control module is used for reducing the carrier frequency of the motor body and the motor controller when the pure electric vehicle is in a launch starting mode so as to inhibit the loss and heat productivity of the motor controller;

the second control module is used for driving the motor rotor to rotate by a specific angle when the pure electric vehicle is in an ejection starting mode so as to reduce motor rotor-locked current;

and the third control module is used for increasing the flow of the cooling liquid flowing through the motor controller and the motor body and reducing the temperature of the cooling liquid so as to enhance the heat dissipation of the motor body and the motor controller when the pure electric vehicle is in the launch starting mode.

According to a third aspect of the present invention, an electronic device is provided, which includes a memory and a processor, wherein the processor is configured to implement the steps of the pure electric vehicle launch start control method when executing a computer management program stored in the memory.

According to a fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer management program is stored, and the computer management program, when executed by a processor, implements the steps of the pure electric vehicle launch start control method.

The invention provides a pure electric vehicle launch start control method and a control system, which start from two directions of inhibiting heating and enhancing heat dissipation and aim to reduce the risk of motor stalling and damage in the pure electric vehicle launch start torque holding stage.

Drawings

FIG. 1 is a flow chart of a pure electric vehicle launch starting control method provided by the invention;

FIG. 2 is a schematic view of the angle of rotation of the drive stator;

FIG. 3 is a schematic diagram of an implementation process of the pure electric vehicle launch starting;

FIG. 4 is a schematic diagram of a pure electric vehicle launch starting control flow;

FIG. 5 is a schematic structural diagram of a pure electric vehicle launch starting control system provided by the invention;

FIG. 6 is a schematic diagram of a hardware structure of a possible electronic device according to the present invention;

fig. 7 is a schematic diagram of a hardware structure of a possible computer-readable storage medium provided in the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

When a motor of the pure electric vehicle normally rotates, a rotating magnetic field formed by the stator winding drags the rotor to rotate, and a magnetic field generated by the induced current in the rotor induces counter electromotive force, namely inductive reactance, in the stator winding, so that the effect of preventing the stator current of the motor from increasing is achieved.

And the catapult starting torque holding stage is a motor locked-rotor state, the motor is in a static state at the moment, the counter electromotive force is zero, and a stator winding of the motor is equivalent to an inductance element under the action of bus voltage and only has self resistance and inductance. The high voltage is applied to the stator windings entirely and the current is abnormally large. At the moment, the stator can quickly heat, so that the motor is demagnetized and even a winding is burnt.

Therefore, the method starts from two directions of inhibiting heating and enhancing heat dissipation, and aims to reduce the motor stalling damage risk in the launch starting torque keeping stage.

Fig. 1 is a flowchart of a pure electric vehicle launch start control method provided by the invention, and as shown in fig. 1, the launch start control method mainly includes:

a. when the pure electric vehicle is in the launch starting mode, the loss and heat productivity of the motor controller are inhibited by reducing the carrier frequency of the motor body and the motor controller.

It can be understood that, for the motor controller of the pure electric vehicle, the IGBT loss therein mainly comes from the switching loss and the on-state loss. In the locked rotor process, phase current is abnormally increased, and the larger the carrier frequency is, the loss is correspondingly increased, and the heat generation is increased.

The calculation formula of the switching loss of the IGBT is as follows:

in the formula:

f-IGBT switching frequency (Hz);

e _ (on _ IGBT) — (Inom, Vmon) IGBT turn-on loss (W) under test state;

e _ (off _ IGBT) — (Inom, Vmon) IGBT turn-off loss (W) under test state;

iac-actual output current (A) of the MCU;

vdc — MCU actual bus voltage (V);

Inom-Specification wear test Condition Current (A);

Vnom-Voltage (V) in Specification loss test conditions.

It should be noted that the switching frequency of the IGBT is adjustable, and other parameters are fixed and non-adjustable, and as can be seen from the above equation (1), the larger the switching frequency of the IGBT is, the larger the loss thereof is.

The calculation formula of the IGBT on-state loss is as follows:

in the formula:

vce0 — IGBT on-state forward tube voltage drop (V) (specification);

r-IGBT thermal resistance (K/W) (specification);

I-MCU peak current (A);

m is modulation ratio;

-a power factor.

The above formula (2) represents the loss of the IGBT once switched on and off, and the on-state loss of the IGBT in unit time is P _{t_igbt} F, f is the IGBT switching frequency, which may also be referred to as the carrier frequency.

As can be known from the above equations (1) and (2), the larger the carrier frequency is, the larger the total loss of the IGBTs in the motor controller is, and therefore, in order to reduce the loss heating of the motor controller in the pure electric vehicle launch starting and locked-rotor state, the carrier frequencies of the motor body and the motor controller can be reduced.

When the pure electric vehicle is detected to be in the launch starting mode, loss heating in the motor locked-rotor state can be restrained by reducing the carrier frequency of the motor body and the motor controller.

As an embodiment, when the pure electric vehicle is in the launch start mode, the carrier frequency of the motor body and the motor controller is reduced to suppress the loss heat productivity of the motor controller, including: when the pure electric vehicle is in a launch starting mode, searching a first carrier frequency corresponding to the current vehicle speed in a carrier frequency table according to the current vehicle speed of the pure electric vehicle, wherein the carrier frequency table stores the corresponding relation between the vehicle speed and the carrier frequency; and taking a second carrier frequency obtained by subtracting a set frequency from the first carrier frequency as the reduced carrier frequency, wherein the set frequency is related to the current speed of the pure electric vehicle.

It should be appreciated that in conventional approaches, the carrier frequency of the motor controller will typically vary depending on the vehicle speed, such as a piecewise varying carrier frequency, a linear varying carrier frequency, etc. Therefore, the carrier frequency of the motor controller under the condition of the locked rotor during the catapult starting is not obviously different from the carrier frequency of the motor controller under the conventional starting condition, the motor is in a low rotating speed under the two conditions, and other distinction is not made except the condition.

In the embodiment of the invention, in order to reduce the heating of the motor controller, improve the reliability and increase the judgment of the catapult starting state position. The implementation method is that before the traditional carrier frequency table look-up operation, the judgment condition of the launch starting state bit is added: if the launch starting state bit is Disable (the electric automobile is not in the launch starting mode), the conventional carrier frequency table lookup is still carried out. Specifically, when the electric vehicle is not in the launch start mode, the carrier frequency corresponding to the current vehicle speed is searched in the carrier frequency table according to the current vehicle speed, wherein the carrier frequency table stores the corresponding relationship between the vehicle speed and the carrier frequency, more specifically, the carrier frequency table stores the corresponding relationship between the vehicle speed range and the carrier frequency, and the carrier frequency table can refer to table 1 below.

Table 1 conventional carrier frequency table

Rotating speed of motor

0

～

500

～

2000

～

5000

～

8000

～

12000

～

16000

Carrier frequency

N1

N2

N3

N4

N5

N6

For example, when the current rotation speed is 300rpm, the carrier frequency corresponding to the current rotation speed is N1Hz obtained by the carrier frequency lookup table, and then the motor body and the motor controller are controlled to operate by the carrier frequency of N1 Hz.

And if the launch starting state is Enable (the electric automobile is in the launch starting mode), searching the carrier frequency table of the launch starting mode, wherein the carrier frequency table of the launch starting mode is obtained by revising the traditional carrier table. For the same vehicle speed range, the corresponding carrier frequency (called as a second carrier frequency) in the carrier frequency table of the launch start mode is lower than the corresponding carrier frequency (called as a first carrier frequency) in the traditional carrier frequency table.

In a specific implementation process, the carrier frequency table of the launch start mode may be updated according to a conventional carrier frequency table, which may be referred to as table 2, where N1 is smaller than N1.

Table 2 carrier frequency table in launch start mode

Rotational speed of motor

0

～

500

～

2000

～

5000

～

8000

～

12000

～

16000

Non-ejection

N1

N2

N3

N4

N5

N6

Ejection device

n1

N2

N3

N4

N5

N6

And then according to the current speed of the electric automobile, searching a corresponding carrier frequency in a carrier frequency table of the launch starting mode.

Or, in another mode, when the electric vehicle is in the launch starting mode, according to the current vehicle speed of the vehicle, the corresponding first carrier frequency is searched in the conventional carrier frequency table, and then the set frequency is subtracted on the basis of the first carrier frequency to obtain the second carrier frequency, so that the second carrier frequency is smaller than the first carrier frequency. The setting frequency subtracted on the basis of the first carrier frequency can be different in different vehicle speed ranges, and in concrete implementation, the setting frequency can be correspondingly set according to the vehicle speed ranges.

For example, when the electric vehicle is in a launch start mode, when the current rotation speed of the vehicle is 0rpm, the corresponding carrier frequency is found to be N1Hz through a traditional carrier frequency table, then the carrier frequency is reduced by 2kHz on the basis of N1Hz, and the reduced carrier frequency is N1 Hz. Or directly searching the carrier frequency n1Hz corresponding to the rotating speed 0rpm according to the updated carrier frequency table of the catapult starting mode.

In which form, the reduced carrier frequency is obtained, and the embodiment of the present invention is not particularly limited. By adopting the method, the running carrier frequency of the motor body and the motor controller can be reduced under the locked-rotor state of the motor, so that the heating of the motor body and the motor controller is inhibited.

b. When the pure electric vehicle is in the launch starting mode, the motor rotor is driven to rotate by a specific angle so as to reduce the motor rotor-locked current.

It can be understood that, in addition to the manner of suppressing the heat generation of the motor body and the motor controller by reducing the carrier frequency of the operation of the motor body and the motor controller in the motor locked-rotor state in step a, when the pure electric vehicle is in the launch start mode, the motor rotor is driven to rotate by a specific angle, so that the current heat generation is reduced by reducing the phase current of the motor locked-rotor.

Wherein, if the motor adopts star connection, when the motor works normally, the vector phases of the three-phase current are 120 degrees different from each other, and the three-phase current is sine alternating current when the rotor rotates, I _a +I _b +I _c ＝0。

However, when the motor is locked, the rotor is fixed at a certain position, the position of the rotor magnetic field is also fixed, and the stator current vector is correspondingly fixed in the corresponding direction. At the moment, the magnetic field of the rotor has unbalanced influence on each phase of magnetic circuit, so that three-phase current is changed into direct current, and the steady-state amplitude of the three-phase direct current is unequal.

When the motor is in a locked-rotor state, the three-phase copper loss expression of the motor is as follows:

P _u ＝(Icosθ) ² *R；

wherein, P _u For first phase copper loss, P _v For second phase copper consumption, P _w And theta is the copper loss of the third phase, theta is the locked rotor position angle, I is the current, and R is the resistance. When the motor is locked, the copper loss of each phase of stator winding is in a sine relationship with the space vector position of the stator current. According to actual measurement, when the phase is at different positions theta, because the amplitude difference of direct currents of three phases is large, the heat productivity difference of each phase is also large, and the phase winding which generates heat most seriously is often burnt out firstly. Therefore, if the rotor can be rotated to a specific position in advance to avoid a locked rotor poor position, and the locked rotor current on a single phase can be reduced, the locked rotor reliability can be improved.

Based on the above, after the electric automobile is identified to be in the launch starting mode, the embodiment of the invention drives the rotor to rotate by a specific angle, and reduces the rotor-locked current.

As an embodiment, when the pure electric vehicle is in a launch start mode, the driving motor rotor rotates by a specific angle to reduce motor locked-rotor phase current includes: determining a locked rotor test point position with minimum temperature rise on a motor stator winding; and determining a specific angle at which the motor rotor needs to be driven to rotate based on the zero position of the motor and the locked rotor test point position of the minimum temperature rise, and driving the motor rotor to rotate to the specific position in the launch starting mode.

Wherein, confirm the stifled commentaries on classics test point position of minimum temperature rise on motor stator winding, include: and uniformly selecting n locked rotor test point positions in the circumferential direction of the motor stator winding, testing the temperature rise at each locked rotor test point position, and determining the locked rotor test point position with the minimum temperature rise.

It can be understood that in the conventional scheme, the motor is blocked to an unexpected state, so that the motor blocking position θ cannot be predicted, and the actual heating of the winding cannot be controlled.

In the embodiment of the invention, the judgment of the launch starting state position is added, so that the motor is blocked to be in an expected state. The method for determining the position of the locked rotor test point with the minimum temperature rise on the motor stator winding comprises the steps of measuring the amplitude of three-phase current and the corresponding temperature rise under the condition that different motor locked rotor positions theta are calibrated on a rack in advance, for example, n locked rotor test points are uniformly selected along the circumferential direction of the motor stator winding, namely one test point is selected at intervals of 360/n mechanical angles, the temperature rise corresponding to each test point is measured, the test point corresponding to the minimum temperature rise is set as the optimal locked rotor position theta, and the temperature rise corresponding to each test point is shown in a table 3.

TABLE 3 temperature rise corresponding to different locked rotor position points

Assuming cn < c1 < b2, it can be seen from table 3 that the temperature rise at the locked-rotor position point n is the minimum, and therefore, the locked-rotor position point n is the optimal locked-rotor position point.

Writing the obtained optimal locked rotor position theta into a locked rotor control logic, and if the catapult starting state position is Disable, not influencing motor control; and if the launch starting state is Enable, controlling the rotor to rotate by a certain angle to Enable the rotor to move to the optimal locked-rotor position theta before starting, wherein the rotation angle is very small, so that the user experience is basically not influenced.

The rotation angle of the motor rotor is controlled to be determined based on the locked rotor test point position of the motor zero position and the minimum temperature rise, as shown in fig. 2, wherein the included angle between the motor zero position and the optimal locked rotor position is the angle required to drive the stator to rotate. When a specific angle required for driving the motor rotor to rotate is determined, the motor rotor is driven to rotate to a specific position in the launch starting mode.

And b, after the electric automobile is identified to enter the launch starting mode, driving the rotor to rotate by a specific angle, reducing the phase current of the rotor, and further inhibiting the motor from generating more heat.

c. When the pure electric vehicle is in the launch starting mode, the flow of the cooling liquid flowing through the motor controller and the motor body is increased, the temperature of the cooling liquid is reduced, and the heat dissipation of the motor body and the motor controller is enhanced.

It can be understood that, the steps a and b are to reduce the heat generation when the motor is in the locked-rotor state from the direction of suppressing the heat generation, and in addition to reducing the heat generation, enhancing the heat dissipation is also an effective means for improving the reliability. The step reduces the motor locked-rotor damage risk in the launch starting torque keeping stage from the direction of enhancing heat dissipation.

The measures for enhancing the heat dissipation are mainly to actively increase the flow of the cooling liquid flowing through the motor controller and the motor body and reduce the temperature of the cooling liquid after recognizing that the electric automobile enters the launch starting mode. Wherein, the coolant liquid flows through the motor controller and the motor winding, so that the heat can be quickly dissipated. If can reduce the coolant temperature and improve the flow fast when the locked-rotor, then can take away more heats, avoid overheated.

As an embodiment, when the pure electric vehicle is in the launch start mode, the flow rate of the coolant flowing through the motor controller and the motor body is increased, and the temperature of the coolant is reduced, so as to enhance the heat dissipation of the motor body and the motor controller, including: when the pure electric vehicle is in the launch starting mode, the VCU of the vehicle control unit outputs a PWM wave control signal with an increased duty ratio to drive the water pump and the cooling fan to operate, so that the rotating speeds of the water pump and the cooling fan are increased, the flow of cooling liquid flowing through the motor controller and the motor body is increased, and the temperature of the cooling liquid is reduced.

It can be appreciated that in conventional schemes, the VCU will adjust the speed of the water pump and cooling fan in real time based on the motor controller and motor winding temperature. The higher the rotating speed of the water pump is, the higher the flow rate of the cooling liquid is; the greater the cooling fan speed, the lower the coolant temperature. If the conventional scheme is used for heat dissipation control, the size and temperature of the cooling liquid are a gradual process. That is, as the locked-rotor temperature rises, the coolant flow rate gradually increases, and the coolant temperature gradually decreases. Therefore, during the specified locked-rotor time, there is a series of actions of temperature sampling, temperature processing, signal transmission, logic processing, instruction sending, and execution of the water pump and the fan, and the efficiency of heat dissipation is reduced.

In the embodiment of the invention, the judgment of the launch starting state position is added. The implementation method is that in the conventional heat dissipation logic, the judgment condition is added: if the catapult starting state is disabled, conventional water pump and fan control is still carried out; if the launch starting state is Enable, the VCU outputs a 100% PWM wave control signal, and the water pump and the fan work according to the maximum capacity. When a user prepares for catapult starting, the maximum heat dissipation capacity is prepared in advance, the time of temperature sampling, temperature processing and signal transmission is saved, and the heat dissipation efficiency is improved.

It should be noted that, the heat generation inhibiting manner and the heat generation enhancing manner in the steps a, b and c are all performed when the electric vehicle is in the launch start mode, and therefore, in an actual implementation process, a status bit is set to mark whether the current vehicle is in the launch start mode. Specifically, referring to fig. 3, the launch start process of the electric vehicle is as follows:

1. the conditions of the catapult starting precondition are met: selecting a Sport mode and setting a gear to be a D gear according to the driving preference of the vehicle;

2. the HMI opens the launch starting function: the HMI of the vehicle develops a button of a launch starting mode, and when a driver actively clicks, the launch starting Enable state position is informed to a VCU, a motor controller and the like (in addition, a launch starting function can be started through the combination of an accelerator and a brake);

3. deep stepping on a brake pedal: the condition is considered to be met only when the deep stepping on the brake pedal is larger than a fixed stroke (calibration in a development stage);

4. and (3) deeply stepping on an accelerator pedal, and activating a launch starting mode: the condition is considered to be met only when the accelerator pedal is deeply stepped on by more than a fixed stroke (calibrated in a development stage). At the moment, the launch starting mode is activated, the motor is fixed, but the torque is preloaded, and then the locked-rotor state is achieved;

5. releasing the brake pedal: after the launch starting mode is activated, a brake pedal needs to be released, and the condition is considered to be met only when the brake pedal is released and is less than a fixed stroke (calibrated in a development stage);

6. judging the time from activating ejection starting to releasing the brake: when the launch start is activated, the HMI will prompt "please release the brake pedal completely within n seconds". When the driver releases the pedal, the VCU calculates the activation-to-release interval. If the time is more than n seconds (calibrated in a development stage), the launch start fails, the VCU requests the motor controller to output 0Nm, and the launch start state bit is set to Disable; if the time is less than n seconds, the catapult starting is successful, the vehicle accelerates, and the catapult starting state position is set to Enable;

7. judging the conditions for the launch start and the exit: and (4) setting exit logic according to the vehicle speed, the accelerator pedal, the acceleration time and the like, exiting the launch starting mode if preset conditions are met, resetting the launch starting state bit to Disable, and ending the whole process.

The launch starting state position of the electric automobile is set through the steps 1-7, and when the electric automobile is started, whether the electric automobile is in a launch starting mode or not can be judged by checking the launch starting state position. The measures for suppressing heat generation and enhancing heat dissipation of the embodiment of the present invention take effect in the step of "HMI opens the launch start function", and the action principle will be described in detail below as shown in fig. 4.

The HMI opens the launch starting, and sets the launch starting state position as Enable; the HMI closes the catapult starting, and sets the catapult starting state position as Disable. When the electric automobile starts, whether the electric automobile is in a launch starting mode or not is judged through a launch starting state position, and when the electric automobile is in the launch starting mode, the heating of the motor and the motor controller can be restrained in a mode of reducing the running carrier frequency of the motor body and the motor controller and/or controlling the stator to rotate by a certain angle; and the working capacity of the water pump and the fan is enhanced to enhance the flow of the cooling liquid flowing through the motor controller and enhance the heat dissipation capacity by reducing the temperature of the cooling liquid.

Fig. 5 is a structural diagram of a pure electric vehicle launch starting control system provided in an embodiment of the present invention, and as shown in fig. 5, the pure electric vehicle launch starting control system includes a first control module 51, a second control module 52, and a third control module 53, where:

the first control module 51 is used for reducing carrier frequencies of the motor body and the motor controller to inhibit loss and heat productivity of the motor controller when the pure electric vehicle is in an ejection starting mode; the second control module 52 is used for driving the motor rotor to rotate by a specific angle when the pure electric vehicle is in an ejection starting mode so as to reduce motor rotor-locked current; and the third control module 53 is configured to increase the flow rate of the coolant flowing through the motor controller and the motor body and reduce the temperature of the coolant so as to enhance the heat dissipation of the motor body and the motor controller when the pure electric vehicle is in the launch start mode.

It can be understood that the pure electric vehicle launch start control system provided by the invention corresponds to the pure electric vehicle launch start control methods provided by the foregoing embodiments, and the relevant technical features of the pure electric vehicle launch start control system may refer to the relevant technical features of the pure electric vehicle launch start control method, and are not described herein again.

Referring to fig. 6, fig. 6 is a schematic view of an embodiment of an electronic device according to an embodiment of the invention. As shown in fig. 6, an embodiment of the present invention provides an electronic device 600, which includes a memory 610, a processor 620, and a computer program 611 stored in the memory 610 and operable on the processor 620, wherein the processor 620 implements the following steps when executing the computer program 611: when the pure electric vehicle is in a launch starting mode, the loss and heat productivity of the motor controller are inhibited by reducing the carrier frequency of the motor body and the motor controller; and/or when the pure electric vehicle is in an ejection starting mode, driving a motor rotor to rotate by a specific angle so as to reduce motor rotor-locked phase current; and/or when the pure electric vehicle is in the launch starting mode, the flow of the cooling liquid flowing through the motor controller and the motor body is increased, and the temperature of the cooling liquid is reduced, so that the heat dissipation of the motor body and the motor controller is enhanced.

Referring to fig. 7, fig. 7 is a schematic diagram of an embodiment of a computer-readable storage medium according to the present invention. As shown in fig. 7, the present embodiment provides a computer-readable storage medium 700 having a computer program 711 stored thereon, the computer program 711, when executed by a processor, implementing the steps of: when the pure electric vehicle is in the launch starting mode, the loss and heat productivity of the motor controller are inhibited by reducing the carrier frequency of the motor body and the motor controller; and/or when the pure electric vehicle is in an ejection starting mode, driving a motor rotor to rotate by a specific angle so as to reduce motor rotor-locked phase current; and/or when the pure electric vehicle is in the launch starting mode, the flow of the cooling liquid flowing through the motor controller and the motor body is increased, and the temperature of the cooling liquid is reduced, so that the heat dissipation of the motor body and the motor controller is enhanced.

The ejection starting control method and the ejection starting control system for the pure electric vehicle provided by the embodiment of the invention have the following technical effects:

(1) compared with the prior art, the invention describes the catapult starting process of the electric automobile in detail and defines the difficulty of the development process of the catapult starting function.

(2) For the catapult starting function, the temperature rise can meet the design requirement in the time of firstly solving the motor stalling, and the motor cannot be burnt or damaged. Therefore, the invention optimizes the existing scheme from two angles (inhibiting heat generation and enhancing heat dissipation), the optimization scheme is to develop a logic algorithm on the basis of the conventional scheme, and the invention has the effects of controllable development scale, lower cost and high reliability.

It should be noted that, in the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to relevant descriptions of other embodiments for parts that are not described in detail in a certain embodiment.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A pure electric vehicle launch start control method is characterized by comprising the following steps:

when the pure electric vehicle is in an ejection starting mode, a motor rotor is driven to rotate by a specific angle so as to reduce motor rotor-locked phase current; and/or the presence of a gas in the gas,

2. The launch control method according to claim 1, characterized in that whether the pure electric vehicle is in the launch start mode is determined by:

acquiring a launch starting state position of the pure electric vehicle;

3. The launch starting control method according to claim 1, wherein when the pure electric vehicle is in the launch starting mode, the carrier frequency of the motor body and the motor controller is reduced to suppress loss heat productivity of the motor controller, and the method comprises the following steps:

4. The launch control method according to claim 3, characterized in that the carrier frequency table stores therein a correspondence between a vehicle speed range and a carrier frequency;

according to the current speed of the pure electric vehicle, the first carrier frequency corresponding to the current speed of the pure electric vehicle is searched in the carrier frequency table, and the method comprises the following steps:

5. The launch control method according to claim 1, wherein when the pure electric vehicle is in the launch mode, the driving motor rotor rotates by a specific angle to reduce motor locked-rotor phase current, and the method comprises the following steps:

6. The launch control method of claim 5, wherein the determining a locked rotor test point location for minimum temperature rise on a motor stator winding comprises:

and uniformly selecting n locked rotor test point positions in the circumferential direction of the motor stator winding, testing the temperature rise at each locked rotor test point position, and determining the locked rotor test point position with the minimum temperature rise.

7. The launch control method according to claim 1, wherein when the pure electric vehicle is in the launch mode, the method for increasing the flow rate of the coolant flowing through the motor controller and the motor body and reducing the temperature of the coolant to enhance the heat dissipation of the motor body and the motor controller comprises the steps of:

8. The utility model provides a pure electric vehicles launch start control system which characterized in that includes:

the first control module is used for reducing the carrier frequency of the motor body and the motor controller to inhibit the loss heat productivity of the motor controller when the pure electric vehicle is in the launch starting mode;

9. An electronic device, characterized by comprising a memory and a processor, wherein the processor is used for implementing the steps of the pure electric vehicle launch start control method according to any one of claims 1 to 7 when executing a computer management program stored in the memory.

10. A computer-readable storage medium, wherein a computer management program is stored thereon, and when executed by a processor, the computer management program implements the steps of the pure electric vehicle launch start control method according to any one of claims 1 to 7.