CN110549913A - Thermal management system for whole electric tractor and control method thereof - Google Patents

Abstract

The invention provides a complete electric tractor thermal management system and a control method thereof, including a power battery thermal management system and a dual-motor thermal management system. Heat exchange is also realized between the power battery and the dual-motor thermal management system through a heat exchanger. The control method of the thermal management system of the electric tractor includes: the thermal management control method of the power battery and dual motors when the tractor is operating, and the thermal management control method of the power battery when the tractor is charging, specifically by setting the temperature level of the power battery and the critical work of the dual motors For temperature, the real-time temperature T of the power battery measured by the temperature sensor and the real-time temperatures _Tmain ' and _Tau ' of the dual motors are used as identification parameters, and the mode of the tractor thermal management system is adjusted in combination with the state of the tractor. The invention ensures that the power battery and the main and auxiliary motors work at a suitable temperature, effectively reduces the energy consumption of the battery, and improves the continuous working time of the tractor.

Description

Thermal management system and control method of electric tractor

technical field

The invention belongs to the technical field of vehicle heat management, and in particular relates to an electric tractor complete machine heat management system and a control method thereof.

Background technique

In recent years, environmental and energy issues have increasingly attracted global attention. Traditional fuel tractors have problems such as exhaust emissions, vibration, and noise pollution when operating, and are not suitable for operating in a closed greenhouse environment. Compared with traditional tractors, electric tractors are low-emission, green and clean, and flexible in control. The power source uses electric energy instead of fuel, which can effectively alleviate the energy crisis.

Continuous operation time is one of the main bottlenecks restricting the development of electric tractors. In addition to developing power batteries with high energy density, ensuring that the drive motor and power batteries can work in a reasonable temperature zone can improve the service life and continuous operation time of the whole machine. The battery needs to be heated when it is charged at low temperature and started at low temperature. During operation, high temperature will affect the capacity and service life of the battery. When the temperature is too high, thermal runaway may occur and cause danger. At present, most electric tractors are only equipped with a battery air cooling system, which fails to properly control the battery temperature. And in the case of low temperature, the heat generated by the motor is not supplemented to the power battery, resulting in waste of energy and reducing the continuous operation time.

Contents of the invention

In order to solve the above problems, the present invention provides an electric tractor complete machine thermal management system and its control method, which can solve the problems of low heat dissipation efficiency of the power battery and unreasonable use of the heat of the motor, thereby ensuring efficient operation of the system, reducing power consumption, and increasing the power consumption of the tractor. continuous working time.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The thermal management system of the electric tractor is characterized in that it includes a battery thermal management system, a dual-motor thermal management system, a heat exchanger and a controller, and both the battery thermal management system and the dual-motor thermal management system are connected to a thermal A heat exchanger for exchange; the battery thermal management system is connected with the power battery of the electric tractor and the on-board charger, and the battery thermal management system includes a battery radiator, an expansion tank I, a heater, an electronic water pump I and a temperature sensor I. The battery radiator is connected to the power battery through the input end, and the output end of the battery radiator is also connected to the expansion tank I, and the expansion tank I is also connected to the on-board charger through the heat exchanger In the heater, the heater is connected to the input end of the electronic water pump I, and the output end of the electronic water pump I is also connected to the power battery, and the power battery is also connected to the temperature sensor I; the battery The thermal management system is also connected to the dual-motor thermal management system through the heat exchanger; the dual-motor thermal management system is connected to the main motor, the main motor controller, the auxiliary motor, the auxiliary motor controller and the DC/DC The dual-motor thermal management system includes a motor radiator, an expansion tank II, an electronic water pump II, an electric control valve for the main motor, an electric control valve for the auxiliary motor, a temperature sensor II, and a temperature sensor III. The auxiliary motors are all connected to the motor radiator, and the motor radiator is also connected to the expansion tank II through the heat exchanger, and the expansion tank II is connected to the electronic water pump through the DC/DC converter II, the electronic water pump is also connected with the electric control valve of the main motor and the electric control valve of the auxiliary motor, the electric control valve of the main motor is connected to the main motor through the controller of the main motor, and the electric control valve of the auxiliary motor The motor electric regulating valve is connected to the auxiliary motor through the auxiliary motor controller, and the main motor and the auxiliary motor are also respectively connected to the temperature sensor II and the temperature sensor III.

Further, the battery thermal management system and the dual-motor thermal management system also include a phase change material, a battery cooling fan and a motor cooling fan, the battery cooling fan is arranged outside the battery radiator, and the motor The cooling fan is arranged outside the radiator of the motor, and the phase change material and the temperature sensor I are also arranged inside the power battery pack.

Further, the temperature sensor I, temperature sensor II and temperature sensor III also transmit the real-time temperatures of the power battery, the main motor and the auxiliary motor to the input terminal of the controller, and the output terminal of the controller is also connected to the main motor for electric adjustment. valve, auxiliary motor electric regulating valve, electronic water pump II, motor cooling fan, motor radiator, electronic water pump I, battery cooling fan, battery radiator and heat exchanger.

Further, the on-board charger and the power battery are arranged at the front end of the vehicle frame, the heater, electronic water pump I, battery radiator and expansion tank I are arranged on one side of the power battery, and the other side of the power battery is also It is equipped with the thermal price ventilation, expansion tank II, DC/DC converter, electronic water pump II and motor radiator; the main motor and the auxiliary motor are respectively connected to the power input end of the power coupling device at the rear end of the frame The front end of the main motor is also connected with the main motor controller and the electric regulating valve of the main motor in sequence, and the front end of the auxiliary motor is also connected with the auxiliary motor controller and the electric regulating valve of the auxiliary motor in sequence.

Further, the main motor, the controller of the main motor, and the electric regulating valve of the main motor are arranged in parallel with the auxiliary motor, the controller of the auxiliary motor, and the electric regulating valve of the auxiliary motor respectively.

Further, the controller is arranged between the power battery, the main motor controller, and the auxiliary motor controller.

The present invention also provides a control method for the heat dissipation management system of the electric tractor, which is characterized in that: the specific steps are:

Step 1. Preset two temperatures t ₁ and t ₂ for the real-time temperature T of the power battery, define t ₁ < t ₂ , and the temperature range t ₁ ~ t ₂ is the optimal working temperature of the power battery;

Step 2, set the critical temperature t ₃ for the real-time temperature T _main ' and T _auxiliary ' of the main motor and the auxiliary motor;

Step 3. When the tractor is started, start the heat dissipation management system of the electric tractor, and measure the real-time temperature T of the power battery, the real-time temperature T of the _main motor, and the real-time temperature T of the auxiliary motor measured by the temperature sensor Ⅰ, temperature sensor Ⅱ and temperature sensor Ⅲ. The _sub ' is collected and sent to the controller, and the controller judges T, T _main ' and T _sub ';

Step 4. When the tractor is not started, it is judged whether the tractor is in the charging state. If so, the real-time temperature T of the power battery is judged;

Further, in steps 3 and 4, the controller judges T and then controls the battery thermal management system. When the real-time T temperature of the power battery exceeds the temperature upper limit _t2 of the control domain, the controller controls the electronic water pump I and the battery cooling fan and the battery radiator are turned on; when the real-time temperature T of the power battery is within the control domain range t ₁ ~ t ₂ , the electronic water pump I, the battery cooling fan and the battery radiator are not started, and the phase change material in the power battery pack absorbs heat Or release heat to cool or heat the battery; when the real-time temperature T of the power battery is lower than the lower limit _t1 of the control domain temperature, the heat exchanger is turned on, the heater is turned on, the electronic water pump I is turned on, and then returns to judge T again.

Further, in step 3, after the controller judges T _main ' and T _auxiliary ', it also controls the thermal management system of the dual motors. When the real-time temperatures of the main and auxiliary motors T _main ' and T _auxiliary ' exceed the critical temperature _t3 , the controller controls the electric control valve of the main motor, the electric control valve of the auxiliary motor, the electronic water pump II, the motor radiator, and the cooling fan of the motor to open; when the real-time temperature T of _{the main} motor exceeds the critical temperature t ₃ , the real-time temperature of the _auxiliary motor T When the critical temperature t ₃ is not exceeded, the electric regulating valve of the main motor, electronic water pump II, motor radiator, and cooling fan are turned on, and the electric regulating valve of the auxiliary motor is closed; when the real-time temperature T of _{the main} motor does not exceed the critical temperature t ₃ , the auxiliary motor When the temperature Tau’ exceeds the critical temperature _t3 , the _auxiliary motor’s electric regulating valve, electronic water pump II, motor radiator, and electrode cooling fan are turned on, and the main motor’s electric regulating valve is closed; otherwise, when the real-time temperatures of the _main and auxiliary motors Tmain’ and None of the T _auxiliary 's exceeds the critical temperature t ₃ , so return directly and re-judgment of T _main ' and T _auxiliary '.

The beneficial effects of the present invention are: the electric tractor complete machine thermal management system and its control method of the present invention, aiming at the electric tractor coupled and driven by dual motors, the complete machine thermal management system provided includes a power battery thermal management system and a dual motor thermal management system , which can realize its independent operation. Among them, the power battery thermal management system organically combines liquid cooling and phase change materials to achieve efficient thermal management of the battery. At the same time, the power battery thermal management system is connected to the motor thermal management system through a heat exchanger, which can realize the function of using the waste heat of the motor to heat the power battery, thereby avoiding energy waste. In addition, combined with the thermal management control method provided by the whole machine thermal management system, the tractor can ensure that the power battery and dual motors are at a suitable working temperature when the tractor is working or charging, and the continuous working time of the tractor driven by the dual motor coupling can be maximized. .

Description of drawings

Fig. 1 is a schematic structural view of the electric tractor complete machine thermal management system of the present invention;

Fig. 2 is a schematic diagram of the chassis layout of the electric tractor complete machine thermal management system of the present invention;

Fig. 3 is a flow chart of the control method of the complete electric tractor thermal management system of the present invention.

Among them, the labels in the figure are: 1. Controller; 2. Auxiliary motor electric control valve; 3. Auxiliary motor controller; 4. Temperature sensor III; 5. Auxiliary motor; 6. Motor cooling fan; 7. Main motor electric control valve. Regulating valve; 8. Main motor controller; 9. Main motor; 10. Motor radiator; 11. Electronic water pump II; 12. DC/DC converter; 13. Temperature sensor II; 14. Expansion tank II; 15. Heater Exchanger; 16. Phase change material; 17. Power battery; 18. Battery cooling fan; 19. Battery radiator; 20. Expansion tank Ⅰ; 21. Temperature sensor Ⅰ; 22. Electronic water pump Ⅰ; 23. Heater; 24 , car charger; 25, steering wheel; 26, driving wheel; 27, transmission device; 28, power coupling device.

Detailed ways

In order for those skilled in the art to better understand the technical solutions provided by the present invention, the following will be described in conjunction with specific embodiments.

Fig. 1 is a structural schematic diagram of the electric tractor complete machine thermal management system of the present invention. The electric tractor complete machine thermal management system provided by the present invention includes two systems, respectively a power battery thermal management system and a dual-motor thermal management system. The thermal management system of the power battery is connected with the thermal management system of the electric motor through a heat exchanger 15 to realize heat exchange.

Among them, the power battery thermal management system adopts a liquid cooling-phase change material comprehensive cooling method, and its system includes a battery radiator 19, a battery cooling fan 18, an expansion tank I20, an electronic water pump I22, a heater 23, an on-board charger 24, and a temperature sensor I21 and phase change materials16. One side of the battery radiator 19 is connected to the power battery 17, and the other end is connected to the expansion tank I20, the expansion tank I20 is connected to the heat exchanger 15, the heat exchanger 15 is connected to the on-board charger 24, and the on-board charger 24 is connected to the heater 23 , the heater 23 is connected with the electronic water pump I22, and the electronic water pump I22 and the power battery 17 form a circuit. When the power battery 17 needs to cool down, the heat of the power battery 17 can be taken out through the water, pass through the battery radiator 19, flow into the expansion tank I20, and then flow back to the power battery 17 through the on-board charger 24 and the electronic water pump I22 to cool down the battery pack. At the same time, it also cools down the on-board charger 24; when the power battery 17 needs to be heated, the electronic water pump I22 pumps water out of the expansion tank I20, passes through the heater 23, and then flows into the power battery 17 to heat the battery pack; the phase change material 16 and the temperature sensor I21 is arranged inside the power battery pack, and the cooling of the phase change material 16 uses its own physical state to absorb or release heat to cool or heat the battery. When the power battery 17 works at a high temperature, the heat generated by the battery pack will be absorbed and stored by the phase change material, thereby effectively controlling the temperature rise of the battery pack. When the battery works at a low temperature, the phase change material 16 will store the heat. The heat is released to heat the battery pack. Therefore, the temperature change of the battery pack can be effectively controlled.

Among them, the dual-motor thermal management system adopts liquid cooling method, and its system includes auxiliary motor electric control valve 2, auxiliary motor controller 3, temperature sensor Ⅲ 4, auxiliary motor 5, main motor electric control valve 7, main motor controller 8, main motor 9. Temperature sensor Ⅱ13, motor cooling fan 6, motor radiator 10, expansion tank Ⅱ14, DC/DC converter 12, electronic water pump Ⅱ11. Wherein the main motor 9 and the auxiliary motor 5 are connected in parallel, the main motor controller 8, the electric regulating valve 7 of the main motor are connected in series with the main motor 9, the auxiliary motor controller 3, the electric regulating valve 2 of the auxiliary motor and the auxiliary motor 5 are connected in series, thus forming a parallel branch road. Then it is connected in series with the motor radiator 10, the heat exchanger 15, the expansion tank II14, the DC/DC converter 12 and the electronic water pump II11 to form a circuit. When the main motor 9 needs to cool down, the electric control valve 7 of the main motor is opened, and the electric control valve 2 of the auxiliary motor is closed. The heat is taken out of the main motor 9 through the water, passes through the motor radiator 10, and flows back to the expansion tank II14, and then the electronic water pump II11 transfers the cold water to the expansion tank II14. The DC/DC converter 12, the electric control valve 7 of the main motor, and the controller 8 of the main motor are pumped into the main motor 9; when the auxiliary motor 5 needs to cool down, the electric control valve 2 of the auxiliary motor is opened, the electric control valve 7 of the main motor is closed, and the heat The water is taken out of the auxiliary motor 5 and flows back to the expansion tank II 14 through the motor radiator 10, and then the electronic water pump II 11 pumps the cold water into the auxiliary motor 5 through the DC/DC converter 12, the electric control valve 2 of the auxiliary motor, and the controller 3 of the auxiliary motor. When the two motors need to cool down at the same time, the electric control valve 2 of the auxiliary motor and the electric control valve 7 of the main motor are opened, and the heat is taken out of the main motor 13 through the water and flows back to the expansion tank II 14 through the motor radiator 10, and then the electronic water pump 11 will After the cold water passes through the DC/DC converter 12, it is pumped into the main motor 9 and the auxiliary motor 5 through the electric regulating valve 7 of the main motor and the electric regulating valve 2 of the auxiliary motor respectively. Therefore, while controlling the temperature change of the dual motors, it also plays a role in cooling the DC/DC converter 12 , the main motor controller 8 , and the auxiliary motor controller 3 .

The thermal management system of the power battery is connected with the dual-motor thermal management system through the heat exchanger 15 . When the power battery 17 needs to be heated, the heat generated by the motor can be transferred to the power battery 17 through the heat exchanger 15, which reduces the burden on the heater 23 and also reduces the burden on the motor radiator 10 and the motor cooling fan 6, thereby The efficiency of the system is improved, the energy consumption is reduced, and the continuous operation time of the tractor is increased.

Wherein the controller 1 is connected with the temperature sensor II13, the temperature sensor III4 and the temperature sensor I21 for receiving the real-time temperature of the main motor 9, the auxiliary motor 5 and the power battery 17. In addition, controller 1 and auxiliary motor electric control valve 2, main motor electric control valve 7, electronic water pump II11, motor cooling fan 6, motor radiator 10, electronic water pump I22, battery cooling fan 18, battery radiator 19, heat exchange 15 connected to send control commands to adjust the system temperature.

The thermal management system of the electric tractor provided by the present invention can complete the transformation of the required thermal management function through the switching of the heat exchanger 15 and the valve according to the thermal management requirements of each component. It can meet the thermal management requirements of dual-motor tractors, and has high energy utilization.

Fig. 2 is the chassis layout of the electric tractor complete machine thermal management system provided by the present invention, the on-board charger 24 is installed at the front end of the vehicle frame, followed by the power battery 17; the main motor 9 and the auxiliary motor 5 are respectively installed on The power input end of the power coupling device 28; with the vehicle steering wheel 25 as the front end and the vehicle driving wheel 26 as the rear end, the main motor controller 8 and the main motor electric regulating valve 7 are installed at the front end of the main motor 9, and the auxiliary motor controller 3 and the electric regulating valve 2 are installed at the front end of the auxiliary motor; the controller 1 is installed between the power battery and the main and auxiliary motor controllers; the heater 23, the electronic water pump I22, the battery radiator 19 and the expansion tank I20 are installed At the left front end of the frame, and arranged in sequence from front to back; the heat exchanger 15, expansion tank II14, DC/DC converter 12, electronic water pump II11 and motor radiator 10 are installed on the right front of the frame, and are arranged from front to back Arranged in sequence; the motor cooling fan 6 is installed outside the motor radiator 10 , and the battery cooling fan 18 is installed outside the battery radiator 19 .

Fig. 3 is the thermal management control method of the whole electric tractor provided by the present invention, including the following steps:

First, two temperature levels are preset for the real-time temperature T of the power battery 17 , t ₁ and t ₂ in sequence, and t ₁ < t ₂ , where t _{1 to} t ₂ are the optimum working temperatures of the power battery 17 . Secondly, a critical temperature t ₃ is set for the real-time temperatures _Tprincipal ' and _Tauxiliary ' of the main motor 9 and the auxiliary motor 5 .

The system starts to work, and the sensor judges the state of the tractor.

If the tractor starts, the temperature sensor I21, temperature sensor II13 and temperature sensor III4 collect the real-time temperature T of the power battery 17 and the real-time temperature T _main ' and T _auxiliary ' of the motor, respectively, and send them to the controller 1 to judge their temperature.

1) If T>t ₂ , the electronic water pump I22, the battery cooling fan 18, and the battery radiator 19 are all turned on, and the controller 1 controls the electronic water pump I22 according to the change of the real-time temperature T of the power battery 17 to adjust the flow rate. Then return to judge the state of the tractor again.

If t ₂ >T > t ₁ , it is the optimal working temperature of the power battery 17 at this time, the heat dissipation system of the power battery 17 is not activated, and the battery is cooled or heated only by natural air cooling and the heat absorption or release of the phase change material 16 . Then return to judge the state of the tractor again.

Otherwise, ie T<t ₁ , the heat exchanger 15 is turned on, the heater 23 is turned on, the electronic water pump I22 is turned on, and the controller 1 controls the electronic water pump I22 according to the change of the real-time temperature T of the power battery 17 . Then return to judge the state of the tractor again.

2) If T _main '>t ₃ and T _auxiliary '>t ₃ , then the auxiliary motor electric control valve 2, the main motor electric control valve 7, the electronic water pump II11, the motor radiator 10, and the motor cooling fan 6 are all turned on, and the control The device 1 controls the electronic water pump II 11, the electric regulating valve 2 of the auxiliary motor and the electric regulating valve 7 of the main motor according to the changes of the real-time temperature T _main ' and T _auxiliary ' of the dual motors to adjust the speed of flow. Go back and judge the tractor status again.

If T _main '>t ₃ and T _{auxiliary'≤t 3} , then the electric control valve 7 of the main motor, the electronic water pump II 11, the motor radiator 10, and the cooling fan 6 of the motor are turned on, the electric control valve 2 of the auxiliary motor is closed, and the controller 1 Control the electronic water pump II11 and the electric control valve 7 of the main motor according to the changes of the real-time temperature T _main ' and T _auxiliary ' of the dual motors. Then return to judge the state of the tractor again.

If T main'≤t ₃ and T _auxiliary '>t ₃ , then the _auxiliary motor electric control valve 2, electronic water pump II11, motor radiator 10, and motor cooling fan 6 are turned on, the main motor electric control valve 7 is closed, and the controller 1 Control the electronic water pump II11 and the electric control valve 2 of the auxiliary motor according to the change of the real-time temperature T _main ' and T _auxiliary ' of the dual motors. Then return to judge the state of the tractor again.

Otherwise, that is, the two motors have not exceeded the critical operating temperature, return directly, and judge the state of the tractor again.

If the tractor is not started, it is judged whether the tractor is in charging state. If yes, judge the real-time temperature T of the power battery 17 . That is, repeat the steps described in 1) above: if not, it is in an uncharged state and end.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. The present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. Electric tractor complete machine thermal management system, its characterized in that: the system comprises a battery thermal management system, a dual-motor thermal management system, a heat exchanger (15) and a controller (1), wherein the battery thermal management system and the dual-motor thermal management system are connected to the heat exchanger (15) with a heat exchange effect;

The battery thermal management system is connected with a power battery (17) of the electric tractor and a vehicle-mounted charger (24), the battery thermal management system comprises a battery radiator (19), an expansion water tank I (20), a heater (23), an electronic water pump I (22) and a temperature sensor I (21), the battery radiator (19) is connected with the power battery (17) through an input end, the output end of the battery radiator (19) is also communicated with the expansion water tank I (20), the expansion water tank I (20) is also connected with the heater (23) through the heat exchanger (15) and the vehicle-mounted charger (24), the heater (23) is connected with the input end of the electronic water pump I (22), the output end of the electronic water pump I (22) is also connected with the power battery (17), the power battery (17) is also connected with the temperature sensor I (21); the battery thermal management system is also connected to the dual-motor thermal management system through the heat exchanger (15);

The double-motor thermal management system is connected with a main motor (9), a main motor controller (8), an auxiliary motor (5), an auxiliary motor controller (3) and a DC/DC converter (12) of the electric tractor, the double-motor thermal management system comprises a motor radiator (10), an expansion water tank II (14), an electronic water pump II (11), a main motor electric regulating valve (7), an auxiliary motor electric regulating valve (2), a temperature sensor II (13) and a temperature sensor III (4), the main motor (9) and the auxiliary motor (5) are connected with the motor radiator (10), the motor radiator (10) is further connected with the expansion water tank II (14) through a heat exchanger (15), the expansion water tank II (14) is connected with the electronic water pump II (11) through the DC/DC converter (12), the electronic water pump is further connected with the main motor electric regulating valve (7) and the auxiliary motor electric regulating valve (2) ) And the main motor electric regulating valve (7) is connected with the main motor (9) through the main motor controller (8), the auxiliary motor electric regulating valve (2) is connected with the auxiliary motor (5) through the auxiliary motor controller (3), and the main motor (9) and the auxiliary motor (5) are also respectively connected with the temperature sensor II (13) and the temperature sensor III (4).

2. The thermal management system for the whole electric tractor according to claim 1, wherein: the battery thermal management system with two motor thermal management systems still include phase change material (16), battery radiator fan (18) and motor radiator fan (6) respectively, battery radiator fan (18) set up in the outside of battery radiator (19), motor radiator fan (6) set up in the outside of motor radiator (10), phase change material (16) with temperature sensor I (21) still set up inside power battery (17) package.

3. The thermal management system for the whole electric tractor according to claim 2, wherein: temperature sensor I (21), temperature sensor II (13) and temperature sensor III (4) still transmit the real-time temperature of power battery (17), main motor (9) and vice motor (5) to the input of controller (1), main motor electric control valve (7), vice motor electric control valve (2), electronic water pump II (11), motor radiator (6), motor radiator (10), electronic water pump I (22), battery radiator (18), battery radiator (19) and heat exchanger (15) are still connected to the output of controller (1).

4. the thermal management system for the whole electric tractor according to claim 1, wherein: the vehicle-mounted charger (24) and the power battery (17) are arranged at the front end of the vehicle frame, the heater (23), the electronic water pump I (22), the battery radiator (19) and the expansion water tank I (20) are arranged on one side of the power battery (17), and the heat price ventilation, the expansion water tank II (14), the DC/DC converter (12), the electronic water pump II (11) and the motor radiator (10) are further arranged on the other side of the power battery (17); the front end of the main motor (9) is sequentially connected with the main motor controller (8) and the main motor electric regulating valve (7), and the front end of the auxiliary motor (5) is sequentially connected with the auxiliary motor controller (3) and the auxiliary motor electric regulating valve (2).

5. the whole electric tractor heat dissipation management system of claim 1 or 4, characterized in that: the main motor (9), the main motor controller (8) and the main motor electric regulating valve (7) are further arranged in parallel with the auxiliary motor (5), the auxiliary motor controller (3) and the auxiliary motor electric regulating valve (2) respectively.

6. The whole electric tractor heat dissipation management system of claim 5, characterized in that: the controller (1) is arranged between the power battery (17) and the main motor controller (8) and the auxiliary motor controller (3).

7. The control method of the whole heat dissipation management system of the electric tractor according to claim 1, characterized in that: the method comprises the following specific steps:

Step one, presetting two temperatures T ₁ and T ₂ for the real-time temperature T of the power battery (17), defining that T ₁ is greater than T ₂, and defining a temperature range T ₁ ~ T ₂ as the optimal working temperature of the power battery (17);

Step two, carrying out real-time temperature T on the main motor (9) and the auxiliary motor (5)_{Master and slave}' and T_{Auxiliary device}' setting the critical temperature t₃；

Step three, when the tractor is started, the whole heat dissipation management system of the electric tractor is started, and the real-time temperature T of the power battery (17) and the real-time temperature T of the main motor (9) measured by the temperature sensor I (21), the temperature sensor II (13) and the temperature sensor III (4) are measured_{Master and slave}' and secondary motor (5) real-time temperature T_{Auxiliary device}' collect and send to controller (1), controller (1) pair T, T_{Master and slave}' and T_{auxiliary device}' making a judgment;

Step four, when the tractor is not started, judging whether the tractor is in a charging state, if so, judging the real-time temperature T of the power battery (17); if not, namely the electric tractor is in a non-charging state, the whole machine heat dissipation management system of the electric tractor is finished.

8. The control method of the whole heat dissipation management system of the electric tractor according to claim 7 is characterized in that in the third step and the fourth step, the controller (1) controls the battery heat management system after judging T, when the real-time T temperature of the power battery (17) exceeds the upper limit of the control domain temperature T ₂, the controller (1) controls the electronic water pump I (22), the battery heat dissipation fan (18) and the battery radiator (19) to be started, when the real-time T temperature of the power battery (17) is within the control domain range T ₁ ~ T ₂, the electronic water pump I (22), the battery heat dissipation fan (18) and the battery radiator (19) are not started, the phase change material (16) in the power battery (17) absorbs heat or releases heat to cool or heat the battery, when the real-time T temperature of the power battery (17) is lower than the lower limit of the control domain temperature T ₁, the heat exchanger (15) is started, the heater (23) is started, the electronic water pump I (22) is started, then the electronic water pump I (22) is returned, and the.

9. The control method of the whole heat dissipation management system of the electric tractor as claimed in claim 7, wherein: in step three, the controller (1) couples T_{Master and slave}' and T_{Auxiliary device}After judgment, the double-motor thermal management system is also controlled, and when the real-time temperature T of the main motor (5) and the auxiliary motor (5)_{Master and slave}’、T_{Auxiliary device}' both exceed the critical temperature t₃When the electric control device is used, the controller (1) controls the main motor electric control valve (7), the auxiliary motor electric control valve (2), the electronic water pump II (11), the motor radiator (10) and the motor radiating fan (6) to be opened; when the real-time temperature T of the main motor (9)_{Master and slave}' exceeding the critical temperature t₃Real-time temperature T of auxiliary motor (5)_{Auxiliary device}' not exceeding the critical temperature t₃When the motor is started, the main motor electric regulating valve (7), the electronic water pump II (11), the motor radiator (10) and the radiating fan are started, and the auxiliary motor electric regulating valve (2) is closed; when the real-time temperature T of the main motor (9)_{Master and slave}' not exceeding the critical temperature t₃Real-time temperature T of auxiliary motor (5)_{Auxiliary device}' exceeding the critical temperature t₃when the electric control valve (2) of the auxiliary motor, the electronic water pump II (11), the motor radiator (10) and the electrode radiating fan are started, and the electric control valve (7) of the main motor is closed; otherwise, when the real-time temperature T of the main motor (9) and the auxiliary motor (5)_{Master and slave}' and T_{Auxiliary device}' neither exceeds the critical temperature t₃Go back directly to, re-pair T_{Master and slave}' and T_{Auxiliary device}' make a judgment.