CN114643855A

CN114643855A - FSEC-based whole vehicle cooling system and control method thereof

Info

Publication number: CN114643855A
Application number: CN202210372349.2A
Authority: CN
Inventors: 吴勃夫; 李书华; 黄俊杰; 董佳豪; 赵彦; 胡博; 闫骥骋
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2022-04-11
Filing date: 2022-04-11
Publication date: 2022-06-21

Abstract

The invention discloses an FSEC (self-service cooling control) based whole vehicle cooling system which comprises a motor, a motor controller cooling circuit and a battery core cooling circuit, wherein the motor and motor controller cooling circuit comprises a motor controller IGBT (insulated gate bipolar transistor), a motor controller cooling plate, a permanent magnet synchronous motor, a motor water jacket, a radiator, a speed regulating fan, a speed regulating water pump and a temperature sensor, and the battery core cooling circuit comprises a battery core module, the speed regulating fan and the temperature sensor. The invention also discloses a control method of the whole car cooling system based on FSEC, which is based on thermal simulation, collects the temperature information of the motor controller IGBT, the permanent magnet synchronous motor and the battery cell module through the single chip microcomputer according to the real-time running mode of the racing car, the single chip microcomputer outputs PWM signals to the PWM direct current motor driving module after judgment, the PWM direct current motor driving module controls the opening and closing state and the rotating speed of the speed regulating fan and the speed regulating water pump, the intake air quantity is regulated, the water temperature is controlled in a proper range, and the safety, the economy and the dynamic property of the racing car during running are ensured.

Description

FSEC-based whole vehicle cooling system and control method thereof

Technical Field

The invention belongs to the technical field of new energy electric automobiles, and particularly relates to an FSEC (free front end controller) -based whole automobile cooling system and an FSEC-based control method of the whole automobile cooling system.

Background

For electric formula cars, a good overall vehicle cooling system is critical to the performance of the car. In dynamic competitions such as 'endurance race', 'high-speed obstacle avoidance' of the FSEC, a large amount of heat is generated by racing cars during high-speed running, which is a test that the whole vehicle cooling system of the FSEC must face. The main heat sources of the electric formula car are a motor, a motor controller, a battery cell module, a DCDC and the like. The requirements on the working temperature are very strict, and particularly, the motor controller IGBT does not have torque output when the working temperature reaches 125 ℃. Any partial cooling problem can result in inadequate performance of the vehicle. The whole vehicle cooling of most college student's electronic equation motorcycle race in China is only simple cooling system, relies on the fan of the invariable fan of rotational speed in the invariable water pump promotion rivers of rotational speed, the motorcycle race produced the air current when traveling and the battery PACK and realizes the heat dissipation purpose. Although partial heat dissipation requirements can be met, the water pump and the fan are always at constant rotating speeds, so that the endurance of a battery PACK of the racing car is not facilitated (the FSEC electric equation emphasizes light weight, so that the electric quantity of the battery PACK is set for running a durable race right), and therefore the water pump and the fan with adjustable rotating speeds are needed to respectively accelerate the water circulation speed and improve the heat dissipation performance, and the rotating speeds of the water pump and the fan can be automatically adjusted according to the heat dissipation capacity, so that the electric quantity is saved for normal running of the racing car. Therefore, an excellent FSEC whole vehicle cooling system and a control method thereof are very important and necessary for the university student electric formula racing vehicle.

Chinese patent application No. CN202111424184.0 discloses a whole car thermal management system that adjusts cooling fan as required and stops, includes: the vehicle speed sensor, the first temperature sensor, the second temperature sensor, the third temperature sensor, the first pressure sensor, the second pressure sensor and the accelerator pedal position sensor are all connected with an ECU of a vehicle through a CAN bus, meanwhile, a PWM controller capable of controlling the rotating speed of the fan CAN be achieved, and after command signals from the ECU are received, the working state of the cooling fan is controllably adjusted. The invention also discloses a control method of the whole vehicle heat management system for adjusting the start and stop of the cooling fan according to the requirement, the air inlet volume of the air cooling system of the vehicle cabin is adjusted by adjusting the opening and closing state and the rotating speed of the cooling fan, the water outlet temperature of an engine, a radiator of the cooling system and a condenser of the vehicle air conditioning system are controlled to be always kept within the allowable range of the working condition, and the safety and the reliability of the vehicle are ensured. However, the invention is not suitable for formula racing because of the following reasons: firstly, the implementation cost of the invention patent is higher for FSEC, and FSEC competition requires that the university student electric formula racing car has the characteristics of good economy, dynamic property and light weight, while the invention patent needs too much sensor information to be collected, which is not beneficial to the characteristics of economy, dynamic property and light weight of the university student electric formula racing car; secondly, the invention is suitable for the fuel oil automobile with an engine and an air conditioning system, and the power sources of the electric formula car are a motor and a power battery and have no air conditioning system, so that the invention is obviously not suitable for the electric formula car; thirdly, the invention does not comprise the design process of a motor water jacket and the design process of radiator model selection, and is not suitable for the electric formula racing of college students; finally, the invention does not include the regulation of the rotating speed of the water pump, can not control the circulating speed of the coolant of the cooling system, and is not suitable for the electric formula racing of college students.

Disclosure of Invention

The invention aims to design and develop an FSEC-based whole vehicle cooling system, which comprises the links of design of a motor water jacket, selection of radiator parameters, controllable adjustment of the rotating speeds of a cooling fan and a water pump and the like. The controllable regulation of the rotating speed of the cooling fan and the water pump is realized by matching a plurality of temperature sensors and a direct current motor driving module with a single chip microcomputer.

The invention also designs and develops a control method of the FSEC-based vehicle cooling system, and the opening and closing states and the rotating speed of the cooling fan and the water pump are controlled by comparing the real-time temperature (including the temperature of the IGBT, the motor, the battery cell and the like) of the vehicle with the set temperature value, so that the devices such as the motor controller, the motor, the battery cell and the like are kept in a better working environment, and the safety and the reliability of the vehicle are ensured.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

according to one aspect of the invention, there is provided an FSEC-based vehicle cooling system comprising: the motor and motor controller cooling circuit and the battery core cooling circuit.

The motor and motor controller cooling circuit includes: the system comprises a motor controller IGBT, a permanent magnet synchronous motor, a motor controller cooling plate, a motor water jacket, a radiator, a speed regulation fan, a speed regulation water pump and a temperature sensor. Wherein, the motor controller is closely attached to the cooling plate of the motor controller, and is coated with heat-conducting silicone grease after combination. The motor controller cooling plate consists of a heat sink made of 6060-T6 aluminum alloy and an integrated cooling channel, heat is dissipated by water flowing through the cooling plate. The permanent magnet synchronous motor is tightly embedded into the motor water jacket, and structural adhesive is coated at the gap, so that the combination strength and the sealing performance are ensured. The motor water jacket is printed by 3D (three-dimensional) nylon materials with good heat dissipation performance, and an inner spiral water channel with small water flow resistance is selected. The radiator is an aluminum strip radiator, the width of the radiating strip is 8mm, the cooling pipes are double rows of twelve layers, and the outer portion of the radiator is connected with a speed regulating fan. The central shaft of the speed-regulating fan is superposed with the center of the radiator to forcibly radiate the radiator. The speed-regulating water pump pushes water flow to circulate quickly. The temperature sensor is used for respectively measuring the temperature of the IGBT and the motor of the motor controller, transmitting the temperature information to the single chip microcomputer, and further controlling the rotating speed of the speed regulation fan and the speed regulation water pump.

The water outlet of the motor controller cooling plate is connected with the water inlet of the motor water jacket, the water outlet of the motor water jacket is connected with the water inlet of the radiator, the water outlet of the radiator is connected with the water inlet of the speed-regulating water pump, the water outlet of the speed-regulating water pump is connected with the water inlet of the motor controller cooling plate to form a loop, and finally heat capacity generated by the IGBT of the motor controller and the PMSM is consumed through the motor and the motor controller cooling loop.

Preferably, plastic tubing with good bending resistance is selected in combination with lightweight aluminum tubing to form the cooling circuit.

Preferably, the bending part is provided with an adapter with an angle larger than or equal to 90 degrees, so that the water flow resistance is reduced.

The cell cooling circuit includes: battery cell module, temperature sensor, speed governing fan. The battery cell module is connected by a plurality of battery cells in a series-parallel connection mode, the battery cells are arranged at intervals, and 5mm ventilation gaps are reserved between the battery cells. The temperature sensor is used for measuring the temperature of the battery cell, transmitting temperature information to the single chip microcomputer, further controlling the rotating speed of the speed regulation fan, and finally leading out the heat capacity to the outside. The speed regulation fan can be selected to carry out speed regulation and heat dissipation according to the temperature difference of the battery cell module or the highest temperature of the battery cell.

Preferably, the temperature sensors adopted by the motor, the motor controller IGBT cooling circuit and the battery core cooling circuit are all temperature-sensitive sensors.

Preferably, the battery cell module temperature-sensitive sensor is arranged on a fixing bolt of a battery cell tab, and a temperature-sensitive sensor is placed every 3 strings of battery cells, so that the battery temperature of 33% of the battery cell of the battery PACK can be effectively measured.

Preferably, the battery cell module shell is printed by adopting a nylon material with good heat dissipation performance, and a heat dissipation channel is reserved on the side surface of the shell.

It should be noted that the single chip microcomputer controls the speed-regulating water pump and the speed-regulating fan by adopting a PWM technology. And the PWM technology is utilized to control each actuator, so that the electric quantity loss can be reduced, and the endurance of the battery PACK is prolonged.

According to another aspect of the invention, a control method of an FSEC-based vehicle cooling system is provided, which is applied to the vehicle cooling system, and comprises the following steps:

during the short-distance or low-intensity running process of the racing car, the FSEC whole car cooling system starts to work, and the fan and the water pump run at a low speed.

For example, when performing "straight line acceleration" or "8-shaped circling" of the FSEC dynamic game, the driving time of the racing car is not too long in general. At this time, the rotation speed of the fan and the water pump is slow. The rotating speeds of the fan and the water pump are automatically adjusted according to the heat dissipation requirement.

During long-distance or high-intensity running of the racing car, the FSEC whole car cooling system starts to work, and the fan and the water pump run at high speed.

For example, when a 'durable race' or a 'high-speed obstacle avoidance' of an FSEC dynamic race is carried out, the 'durable race' requires that the racing car runs for 21km, the 'high-speed obstacle avoidance' requires that the racing car runs with high strength, the heat dissipation requirement on the racing car is very high, and at the moment, the rotating speeds of the fan and the water pump are higher.

If the durable competition needs to be completed, the electric quantity of a battery PACK needs to be reasonably distributed for use, and in the process, the control method of the whole vehicle cooling system starts to play a role. The running time of the racing car at the beginning of a race is short, under the general condition, the temperature of key components of the racing car is not increased, and the rotating speeds of a fan and a water pump are low; when the racing car runs for a long time, the temperature of key components of the racing car generally rises gradually. The singlechip detects that the temperature of the key device rises and then controls the direct current motor driving module through the PWM technology, so that the rotating speed of the fan and the water pump rises, and the heat dissipation is enhanced. When the single chip microcomputer detects that the temperature is reduced by a certain value, the direct current motor driving module is controlled through the PWM technology, so that the rotating speeds of the fan and the water pump are reduced, and the electric quantity is saved. The temperature is finally maintained in a reasonable range by continuously adjusting the rotating speed of the fan and the water pump.

The invention designs and develops a whole vehicle cooling system based on FSEC and a control method thereof, and has the beneficial effects that: through temperature sensor, singlechip and PWM direct current motor drive module mutually support, effectively manage whole car heat, extension battery PACK duration to thermal simulation is the basis, can compare with the settlement temperature value through whole real-time temperature of car (including motor controller IGBT, motor, electric core temperature etc.), to fan and water pump real-time speed governing, the persistence, the security when having guaranteed the cycle racing and traveling, economic nature and dynamic nature for cycle racing comprehensive properties and the driving technique of car driver can full play.

Drawings

FIG. 1 is a schematic view of a cooling system for a vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic view of the cooling channels of the motor controller cooling plate of the present invention;

FIG. 3 is a schematic view of a cooling channel of a water jacket of the motor of the present invention;

FIG. 4 is a simulation diagram of the temperature of the cross section of the motor and the water channel and the overall temperature gradient of the motor water jacket according to the present invention;

FIG. 5 is a schematic diagram of the FSEC-based vehicle cooling system control logic of the present invention;

FIG. 6 is a schematic diagram of the PWM duty cycle of the present invention;

FIG. 7 is a flow chart illustrating a control method of the FSEC-based vehicle cooling system according to the present invention.

Detailed Description

The FSEC-based finished vehicle cooling system and method of controlling the same of the present invention will now be described in greater detail with reference to the schematic drawings, in which preferred embodiments of the invention are shown, it being understood that one skilled in the art may modify the invention herein described while still achieving the advantageous effects of the invention. Accordingly, the following description should be construed as broadly as possible to those skilled in the art and not as limiting the invention.

As shown in fig. 1, 2 and 3, the invention provides an FSEC-based vehicle cooling system. The method comprises the following steps: the motor and motor controller cooling circuit and the battery core cooling circuit.

The motor and motor controller cooling circuit includes: the system comprises a motor controller IGBT, a permanent magnet synchronous motor, a motor controller cooling plate, a motor water jacket, a radiator, a speed regulation fan, a speed regulation water pump and a temperature sensor. It should be noted that the motor and motor controller cooling circuit of fig. 1 only illustrates a simplified model, and in practice the circuit may include multiple speed water pumps, radiators, pmsm, and motor water jackets. In the cooling circuit of the motor and the motor controller, the motor controller IGBT and the permanent magnet synchronous motor are main heating devices, have higher requirement on the temperature of the working environment and are main cooling objects of the cooling circuit of the motor and the motor controller. The motor controller is precisely attached to the cooling plate of the motor controller, and heat-conducting silicone grease is coated on the cooling plate of the motor controller, so that the heat dissipation requirement of the motor controller is met. The motor controller cooling plate consists of a heat sink made of 6060-T6 aluminum alloy and an integrated cooling channel, and heat is dissipated by water flowing through the cooling plate. The motor controller cooling plate cooling channels are shown in fig. 2. Preferably, the distribution of the positions of the cooling channels of fig. 2 corresponds to the actual positions of the IGBTs, so that the heat capacity generated by the IGBTs can be sufficiently taken away.

The permanent magnet synchronous motor is tightly embedded into the motor water jacket, and structural adhesive is coated at the gap, so that the combination strength and the sealing property are ensured. The nylon 3D printing with good heat dissipation performance is applied to the motor water jacket. The motor water jacket cooling channel is shown in fig. 3.

Preferably, the cooling channel of the motor water jacket is an internal spiral water channel with small water flow resistance.

It is worth to be noted that the heat loss generated by the motor is generated by the power loss PV, in order to meet the heat dissipation requirements of the adopted permanent magnet synchronous motor: the coolant temperature must not exceed the maximum allowable inlet temperature by 40 ℃, the minimum flow must be 2L/min, the maximum coolant temperature increase must be less than 5 ℃, so the design process of the water jacket is as follows:

the CATIA establishes a three-dimensional model of a motor and a water jacket in a cooling system.

And introducing the established three-dimensional model into the ANYSY FLUENT, and performing steps of fluid domain creation, mesh division, FLUENT pretreatment, boundary condition establishment and the like.

FLUENT pretreatment comprises the following steps: and opening an energy equation and turbulence, and establishing steady-state thermal analysis. The material is introduced and established, the fluid is set as liquid water, and 3D printing is adopted in consideration of the processing difficulty and processing cost of the water jacket, the material is PA12, the motor material is Steel, and table 1 is the property of the used material.

TABLE 1 Material Properties

Firstly, giving materials to fluid and solid, establishing a heat source, obtaining the heating power of the motor according to the actual working condition, preferably, taking the heating power 1893.4W with the rotating speed of 12000rpm and the torque of 10.4Nm, and the unit of the heat source is W/m³Motor volume 0.0008m³The heating power is 2366750W/m³。

Then, boundary condition establishment is carried out, which comprises the following steps: setting a speed type inlet according to a water pump manual: the minimum flow rate of a 24V water pump is 5L/min, the minimum flow rate meets the requirement of 2L/min, the inner diameter of the spiral pipeline is 9mm according to the size of a fluid area, and the inlet temperature is set to be 20 ℃; a pressure type outlet is arranged, the wall of the water jacket contacting with the air is set to be naturally convected with the air, and the convective heat transfer coefficient is 15W/(m)²K), the ambient temperature is set to 25 ℃; the solution method is a SIMPLE algorithm, in order to improve the precision, a second-order windward format is selected for momentum, turbulence momentum and turbulence kinetic energy dissipation rate, a relaxation factor is set in a default mode, and residual errors are set in a default mode to be 0.001. After initializing the flow field, setting the number of iteration steps to be 1000 steps, and calculating to converge at 240 steps.

And secondly, performing post-processing to generate a motor overall temperature cloud picture and a flow channel flow speed cloud picture, and comparing the highest temperature and the flow speed to select a model with balanced cooling effect and flow speed.

And finally obtaining a simulation result. A simulation graph of the cross section of the motor and the temperature of the water channel and a simulation graph of the overall temperature gradient are shown in figure 4.

The result shows that the temperature amplification is 1.4K and is less than the requirement 5K, and the model meets the heat dissipation requirement of the motor and meets the design requirement.

The radiator is an aluminum strip radiator. Preferably, the width of the heat dissipation belt is 8mm, the cooling pipes are double rows and twelve layers, and the outside of the radiator is connected with the speed regulation fan. The central shaft of the speed-regulating fan is superposed with the center of the radiator to forcibly radiate the radiator. The speed-regulating water pump pushes water flow to circulate quickly.

It is worth to say that the heat sink parameter selection process:

the heating power of the motor is calculated by 5 percent of the total power of the motor. According to the FSEC competition rule, the maximum power of the motor is 80kW, so that the heating power of the motor is 4 kW. According to the specification of the inverter product, the rated output power of a single module is 25kW, the efficiency is 98%, and therefore the heating power of the inverter is 2 kW. The total heating power of the motor and the motor controller is 6 kW.

The heating power is consumed to the outside through the radiator, and the heat radiation area of the radiator is calculated according to the formula:

wherein F is the heat dissipation area, and the unit is m²；Q_ωIn order to dissipate heat power, the unit is kW;

storage factors for radiators, influence of scale and sludge, etc., in general

Δt_mTaking 26 ℃ as the average temperature difference between the cooling water and the air;

wherein alpha is_ωAlpha is the heat release coefficient from the cooling water to the wall of the radiator when the flow rate of the cooling water is 0.2-0.6 m/s_ωAbout 2000 to 3500 kcal/(m)²h.C.) taken at 3500 kcal/(m)²·h·℃)；λ_αThe heat conductivity coefficient of the radiating pipe is 230W/(m.K) of pure aluminum, and the conversion is 197.8 kcal/(m.K)²·h·℃)；δ_αTaking 0.0002m as the thickness of the radiating pipe; alpha is alpha_LAlpha is the heat dissipation coefficient from the heat dissipation tube to the air, when the air flow rate flowing through the heat dissipation tube is 10-20 m/s_L＝60～105kcal/(m²h.C.) taken at 105 kcal/(m)²h.C.), the required heat dissipation area is calculated to be 1.9457m²。

The radiator is selected and designed according to the heat dissipation area of the requirements:

S＝k{[2(a-b)+πb]·(L+6～8)·m·n+4A·B·Z·(n+1)}/10⁶

s is the heat dissipation area of the radiator, and the unit is m²(ii) a k is the heat radiating area coefficient, 1.1 for big water tank k, and for little water tank: k is 1.05; a is the length of the cooling tube, and the unit is: mm; b is the cooling tube width, unit: mm; l is the master pitch, unit: mm; m is the number of rows of cooling pipes; n is the number of cooling pipe layers; a is the peak value of the heat dissipation band, and the unit is as follows: mm; b is the width of the heat dissipation belt, and the unit is as follows: mm; z is the wave peak number of the heat dissipation band, and is L/wave peak distance, and the wave peak distance is 2 mm.

The standard selected in the invention is as follows: the theoretical heat dissipation area was calculated to be 0.9635m, where a × B is 22mm × 2mm, m is 2 (rows), n is 12 (layers), a is 22mm, B is 8mm, L is 160mm, and k is 1.05². The invention comprises three radiators with the same size, and the total radiating area is 3 multiplied by 0.9635m²＝2.8905m²Greater than required heat dissipation area 1.9457m²。

Practical application finds that the heat dissipation area and the water volume of the radiator meet the actual heat dissipation requirements.

The temperature sensor is used for respectively measuring the temperature of the IGBT and the motor of the motor controller, transmitting the temperature information to the single chip microcomputer, and further controlling the rotating speed of the speed regulation fan and the speed regulation water pump. Preferably, the temperature sensor selects a temperature sensitive resistor, and the temperature sensitive resistor in the motor is placed in close contact with the winding; and the thermistor in the motor controller is factory-arranged in the IGBT.

The water outlet of the cooling plate of the motor controller is connected with the water inlet of the motor water jacket, the water outlet of the motor water jacket is connected with the water inlet of the radiator, the water outlet of the radiator is connected with the water inlet of the speed-regulating water pump, and the water outlet of the speed-regulating water pump is connected with the water inlet of the cooling plate of the motor controller to form a loop, as shown in fig. 1. Preferably, plastic tubing with good bending resistance is selected in combination with lightweight aluminum tubing to form the cooling circuit. Preferably, the bent part is provided with a switching port with an angle larger than or equal to 90 degrees, so that the water flow resistance is reduced. Finally, the heat capacity generated by the motor controller IGBT and the permanent magnet synchronous motor is consumed through the motor and motor controller cooling circuit.

The cell cooling circuit includes: battery cell module, temperature sensor, speed governing fan. The battery cell module is connected by a plurality of battery cells in a series-parallel connection mode, the battery cells are arranged at intervals, and 5mm ventilation gaps are reserved between the battery cells. The temperature sensor is used for measuring the temperature of the battery cell, transmitting temperature information to the single chip microcomputer, further controlling the rotating speed of the speed regulation fan, and finally leading out the heat capacity to the outside. The speed regulation fan can be selected to carry out speed regulation and heat dissipation according to the temperature difference of the battery cell module or the highest temperature of the battery cell. As shown in fig. 1.

Preferably, the temperature sensor adopted by the battery cell module is a temperature-sensitive sensor.

Preferably, the battery cell module temperature-sensitive sensor is arranged on a fixing bolt of a battery cell tab, and a temperature-sensitive sensor is placed every 3 strings of battery cells, so that the battery cell temperature of 33% of the battery box can be effectively measured.

Preferably, the battery cell module shell is printed by adopting a nylon material with good heat dissipation performance, and a heat dissipation channel is reserved on the side face of the shell.

In this embodiment, the temperature information of motor controller IGBT, PMSM and electric core module is gathered to the singlechip, and through judging back singlechip output PWM signal gives PWM direct current motor drive module, by PWM direct current motor drive module control speed governing fan and speed governing water pump open and shut state and rotational speed, as shown in fig. 5. And the PWM technology is utilized to control each actuator, so that the loss can be reduced, and the endurance of the battery PACK is prolonged. The PWM duty cycle principle is shown in fig. 6. The duty ratio is the duty ratio of the pulse width time in one period, and different control voltage signals can be changed and output by adjusting the PWM duty ratio.

The beneficial effects of the complete vehicle cooling system based on the FSEC described in the embodiment are as follows: cooperate with the singlechip through a plurality of temperature sensor and direct current motor drive module, can realize gathering the electronic equation motorcycle race temperature information of university student in real time, by singlechip output PWM signal, realize the function of intelligent regulation rotational speed through direct current motor drive module to speed governing fan and speed governing water pump's control, effectively manage whole car heat, extension battery PACK continuation of the journey.

As shown in fig. 7, according to another aspect of the present invention, there is provided a control method for an FSEC-based vehicle cooling system, applied to the vehicle cooling system, including:

For example, when performing "straight acceleration" or "8-round" of the FSEC dynamic race, the running time of the racing car is generally not too long. At this time, the rotation speed of the fan and the water pump is slow. The rotating speeds of the fan and the water pump are automatically adjusted according to the heat dissipation requirement.

For example, when performing a "endurance race" or a "high-speed obstacle avoidance" of the FSEC dynamic race, the "endurance race" requires that the racing car runs for 21km, while the "high-speed obstacle avoidance" requires that the racing car runs with high strength, and the heat dissipation requirement of the racing car is very high. The fan and the water pump rotate at a higher speed.

In addition, in the actual experiment process, the racing car inevitably loses power when running. According to failure mode analysis, the reason that the motor is unpowered is found to be power-down output caused by overheating of an IGBT (insulated gate bipolar transistor) of a motor controller, and power failure caused by overheating of a battery cell.

To cope with the above situation, there is the following determination flow:

when the motor is unpowered, judging whether the IGBT of the motor controller is overheated, if so, controlling the direct current motor driving module to regulate the rotating speed of the fan and the water pump through PWM by the singlechip; and if not, judging whether the battery cell is overheated or not. If the battery core is overheated to cause the BMS to alarm, the singlechip controls the direct current motor driving module to adjust the rotating speeds of the fan and the water pump through PWM; if not, other reasons are discussed.

The control method for the whole vehicle cooling system based on the FSEC has the following beneficial effects that: on the basis of thermal simulation, the opening and closing states and the rotating speed of a cooling fan and a water pump can be controlled by comparing the real-time temperature (including the temperature of an IGBT (insulated gate bipolar transistor), a motor, a battery cell and the like) of the whole car with a set temperature value, and the durability, the safety, the economy and the dynamic property of the racing car during running are ensured, so that the comprehensive performance of the racing car and the driving technology of a driver can be fully exerted.

While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. The finished automobile cooling system based on the FSEC is characterized by comprising a motor, a motor controller cooling loop and a battery core cooling loop.

2. The FSEC-based finished vehicle cooling system as claimed in claim 1, wherein the motor and motor controller cooling circuit comprises:

a motor controller IGBT which is one of the main heat sources;

the motor controller cooling plate is precisely attached to the motor controller IGBT, and the position of the water channel corresponds to the position of the IGBT;

a permanent magnet synchronous motor, which is one of the main heat sources;

the motor water jacket is tightly nested at the outer side of the permanent magnet synchronous motor, and an internal spiral water channel is adopted, so that the water flow resistance is small;

a radiator, the radiating area of which is determined by the radiating requirement calculation result;

the speed regulation fan is directly controlled by the PWM direct current motor driving module, the central shaft of the speed regulation fan is superposed with the center of the radiator and is abutted against the radiator, and the speed regulation can be carried out according to the radiating requirement;

the speed-regulating water pump is directly controlled by the PWM direct current motor driving module, accelerates water circulation and can regulate the speed according to the heat dissipation requirement;

and the temperature sensor is a temperature-sensitive sensor and is used for collecting the temperatures of the IGBT and the permanent magnet synchronous motor of the motor controller and transmitting the temperature information to the singlechip.

3. The FSEC-based finished vehicle cooling system of claim 1, wherein the cell cooling circuit comprises:

the battery cell module is one of main heat sources, and a 5mm ventilation gap is reserved between the battery cell and the battery cell;

the speed-regulating fan is directly controlled by the PWM direct current motor driving module, the front face of the fan is over against the ventilation gap of the battery cell module, and the speed can be regulated according to the requirement;

the temperature sensor is selected and used for collecting the temperature of the battery cell module and transmitting the temperature information to the single chip microcomputer.

4. An entire FSEC-based vehicle cooling system as defined in claim 2, wherein the connection sequence of the electric machine and the components in the motor controller cooling circuit is: the water outlet of the motor controller cooling plate is connected with the water inlet of the motor water jacket, the water outlet of the motor water jacket is connected with the water inlet of the radiator, the water outlet of the radiator is connected with the water inlet of the speed-regulating water pump, and the water outlet of the speed-regulating water pump is connected with the water inlet of the motor controller cooling plate to form a loop; so that heat generated by the motor controller IGBT and the permanent magnet synchronous motor is dissipated through the motor and the motor controller cooling circuit.

5. An FSEC-based vehicle cooling system as claimed in claim 2, wherein the heat loss of the motor is caused by power loss PV, and in order to meet the heat dissipation requirements of the adopted PMSM, namely the coolant temperature is not allowed to exceed the maximum allowable inlet temperature by 40 ℃, the minimum flow rate must be 2L/min, and the maximum coolant temperature increase must be less than 5 ℃, the design calculation steps of the water jacket of the cooling system are as follows:

the method comprises the following steps: the CATIA establishes a three-dimensional model of a motor and a water jacket in a cooling system;

step two: FLUENT pretreatment, opening an energy equation and turbulence, and establishing steady-state thermal analysis. Introducing and establishing a material, setting the fluid as liquid water, and adopting 3D printing in consideration of the processing difficulty and the processing cost of the water jacket, wherein the material is PA 12;

step three: establishing a heat source, and preferably selecting 1893.4W of heating power of the motor under the torque of 12000rpm and 10.4Nm and 0.0008m3 of the volume of the motor according to the actual working condition, wherein the heating power is 2366750W/m 3;

step four: setting boundary conditions, setting a speed type inlet, according to a water pump manual, setting a minimum flow rate of a 24V water pump to be 5L/min, meeting the requirement that the minimum flow of the 24V water pump is required to be 2L/min, according to the size of a fluid area, setting the inner diameter of a spiral pipeline to be 9mm, and setting the inlet temperature to be 20 ℃; a pressure type outlet is arranged, wall of the water jacket contacting with air is set to be naturally convected with the air, the heat convection coefficient is 15W/(m 2K), and the external temperature is set to be 25 ℃; the solution method is a SIMPLE algorithm, in order to improve the calculation accuracy, a second-order windward format is selected for momentum, turbulence momentum and turbulence kinetic energy dissipation rate, a relaxation factor is set by default, and a residual error is set by default to be 0.001; after initializing the flow field, setting the number of iteration steps as 1000 steps, and calculating to 240 steps to converge;

step five: post-processing to generate a motor integral temperature cloud picture and a flow channel flow velocity cloud picture,

step six: analyzing the highest temperature and the flow velocity of the cloud picture, judging whether the water jacket structure meets the requirements, and adopting the water jacket structure if the water jacket structure meets the requirements; if the requirements are not met, the design is improved again, and the step one is returned.

6. A control method of an FSEC-based vehicle cooling system, which uses the FSEC-based vehicle cooling system as claimed in claims 1-5, wherein the device temperature range determination steps are as follows:

the method comprises the following steps: judging whether the motor has power, and dividing the racing car state into a normal state and an abnormal state according to positive and negative results;

step two: when the motor controller is in an abnormal state, judging whether the IGBT of the motor controller is overheated, and judging whether the racing car state is in two states of needing to strengthen heat dissipation and needing to judge whether a battery cell is overheated to cause BMS alarm according to positive and negative results;

step three: when the BMS alarm is caused by the overheating of the battery cell, the state of the racing car can be judged to be two states of heat dissipation enhancement and other states according to positive and negative results;

step four: in a normal state, the temperature of the key device is compared with a set temperature, whether the temperature rises is judged, and two states of acceleration and deceleration of the fan and the water pump can be determined according to positive and negative results;

the four steps can ensure that the temperature of the key device is in a proper range.

7. The control method of the FSEC-based vehicle cooling system as claimed in claim 6, wherein when performing "straight line acceleration" or "8-shaped circling" of FSEC dynamic competition, the running time of the racing vehicle is not too long under normal conditions, at this time, the rotating speeds of the fan and the water pump are slow, and the rotating speeds of the fan and the water pump are automatically adjusted according to the heat dissipation requirement; when carrying out 'endurance match' or 'high-speed obstacle avoidance' of an FSEC dynamic match, the 'endurance match' requires that the racing car runs for 21km, and the 'high-speed obstacle avoidance' requires that the racing car runs with high strength, so that the heat dissipation requirement on the racing car is very high, and at the moment, the rotating speeds of the fan and the water pump are higher.

8. The control method of the FSEC-based vehicle cooling system as claimed in claim 6 or 7, wherein if the durable race is to be completed, the battery PACK electric quantity needs to be reasonably utilized, in the process, the control method of the vehicle cooling system starts to function, the running time of the racing vehicle is short just after the race starts, in general, the temperature of key components of the racing vehicle is not increased, and the rotating speeds of the fan and the water pump are low; when the racing car runs for a long time, under general conditions, the temperature of key devices of the racing car gradually rises, and after the single chip detects that the temperature of the key devices rises, the direct current motor driving module is controlled through a PWM (pulse width modulation) technology, so that the rotating speeds of a fan and a water pump are increased, and heat dissipation is enhanced; when the single chip microcomputer detects that the temperature is reduced to a certain value, the direct current motor driving module is controlled through a PWM technology, and the rotating speeds of the fan and the water pump are reduced so as to save electric quantity; the rotating speeds of the fan and the water pump are continuously adjusted through a PWM technology, and finally the temperature of the cooling system is maintained in a reasonable range.