Battery thermal management system and vehicle

Abstract

A battery thermal management system (100), comprising: a motor (1), wherein the motor (1) is connected to a battery pack (2) by means of a battery thermal management circuit (200); and a controller (40), wherein the controller (40) is connected to the motor (1) and the battery thermal management circuit (200), respectively, and the controller (40) is used for controlling the motor (1) to operate at zero torque on the basis of the state of a vehicle (1000) when the battery pack (2) requires heating, and enabling heat generated by a stator (S) and / or a rotor (F) of the motor (1) to heat the battery pack (2) by means of the battery thermal management circuit (200). The battery thermal management system can improve the utilization rate of devices in the system. Also provided is a vehicle (1000).

Description

Battery thermal management system and vehicle

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202410719765.4, filed on June 5, 2024, entitled "Battery thermal management system and vehicle", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of vehicles, and in particular to a battery thermal management system and vehicle. BACKGROUND

[0004] With the development and rapid popularization of electric vehicles, electric vehicles also face many challenges. Lithium-ion-based power batteries are widely used. Due to the inherent characteristics of the battery, the battery can improve its charging and discharging efficiency and prolong the service life of the battery when charging and discharging at a suitable temperature. However, the charging and discharging capacity of the battery will be greatly reduced at low temperature, which will affect the use of electric vehicles in cold regions. In particular, electric vehicles will experience slow charging, shortened range, and reluctance to turn on the air conditioning heater in winter. "Low temperature anxiety" has become a user experience pain point in the marketization process of electric vehicles. Therefore, how to improve the performance of lithium-ion batteries at low temperature is one of the key problems that need to be solved. Lithium-ion batteries are sensitive to low temperature. The internal resistance of lithium-ion batteries increases sharply at low temperature, and the discharge capacity and charging and discharging performance are greatly limited, resulting in insufficient power performance of electric vehicles in low temperature environment and a significant reduction in driving range. Moreover, the battery cannot be charged below-20℃, and if forced to charge, it is easy to cause internal short circuit and safety hazards. There are many solutions to the low-temperature use of lithium-ion batteries. For example, one solution uses a PTC heater or an electric heating wire heater to heat the cooling liquid of the battery cooling circuit at low temperature, and then heats the battery cell to the predetermined temperature through the cooling liquid. Another solution uses motor zero torque or locked-rotor control strategy to heat the cooling water to achieve the purpose of heating the battery.

[0005] In the prior art, when the first solution is used to heat the battery, an external auxiliary heating device needs to be additionally provided, which increases the cost and the complexity of system design. When the second solution is used to heat the battery, although the external auxiliary heating device is removed, the cost and system complexity are reduced, but when the motor zero torque operation or locked-rotor operation is controlled to heat the cooling water, only the motor stator generates heat, which has a single function, a narrow range of adaptation to the environment, and a low utilization rate of system devices.

[0006] DISCLOSURE

[0007] The present disclosure aims to at least solve one of the technical problems existing in the prior art. To this end, a first object of the present disclosure is to provide a battery thermal management system, which controls the motor to operate at zero torque to heat the battery pack, and the rotor and stator of the motor can heat the battery pack by heating the coolant, thereby achieving more comprehensive functions, wider environmental adaptability, and improved utilization of devices in the system.

[0008] A second object of the present disclosure is to provide a vehicle.

[0009] To achieve the above object, the battery thermal management system according to the first aspect of the present disclosure comprises: a motor connected to a battery pack through a battery thermal management circuit; and a controller connected to the motor and the battery thermal management circuit, respectively, wherein the controller is configured to control the motor to operate at zero torque according to a vehicle state when the battery pack needs to be heated, and to cause the rotor and / or stator of the motor to generate heat to heat the battery pack through the battery thermal management circuit.

[0010] The battery thermal management system according to the present disclosure controls the motor to operate at zero torque according to the vehicle state when the battery pack needs to be heated, and the rotor and stator of the motor can heat the battery pack by heating the coolant, thereby achieving more comprehensive functions, wider environmental adaptability, and improved utilization of devices in the system. In addition, the battery thermal management system takes into account the state of the vehicle while heating the battery pack, so that the vehicle can achieve the function of heating the battery pack by the electric drive system in different states, thereby achieving coordinated control of battery pack heating and vehicle state.

[0011] In some embodiments of the present disclosure, the battery thermal management circuit comprises: a heat pump system connected to a liquid circuit of the battery pack; an electric drive system comprising an oil liquid cooling circuit for cooling the motor, the oil liquid cooling circuit being connected to an oil liquid pipeline of the motor; and a first plate exchanger, the oil liquid cooling circuit being connected to the heat pump system and the battery pack through the first plate exchanger.

[0012] In some embodiments of the present disclosure, the electric drive system further comprises: a stator drive circuit connected to the controller, the stator of the motor, and a charging bus of the battery pack, respectively, for driving the stator of the motor; and a rotor drive circuit connected to the controller, the rotor of the motor, and the charging bus of the battery pack, respectively, for driving the rotor of the motor.

[0013] In some embodiments of the present disclosure, when the vehicle is fault-free and the vehicle is in a parked state and the battery pack has a heating demand, the controller controls the motor to operate at zero torque, wherein the stator is heated by controlling the stator drive circuit and the rotor is heated by controlling the rotor drive circuit.

[0014] In some embodiments of the present disclosure, when the vehicle is fault-free and the vehicle is in a direct charging state and the battery pack has a heating demand, the controller controls the motor to operate at zero torque, wherein the stator is heated by controlling the stator drive circuit and the rotor is heated by controlling the rotor drive circuit.

[0015] In some embodiments of the present disclosure, when the controller controls the stator drive circuit, it is used to obtain a quadrature axis voltage and a direct axis voltage according to a target quadrature axis current, a target direct axis current, a feedback quadrature axis current and a feedback direct axis current, and to obtain a pulse width modulation duty cycle of the stator drive circuit according to the quadrature axis voltage and the direct axis voltage through inverse Park transformation and pulse width modulation algorithm, so as to drive the stator of the motor, wherein the target quadrature axis current is zero.

[0016] In some embodiments of the present disclosure, when the vehicle is fault-free and the vehicle is in a boost charging state, and the battery pack has a heating demand, the controller controls the motor to operate at zero torque, wherein the stator stores energy by controlling the stator drive circuit and the rotor is heated by controlling the rotor drive circuit.

[0017] In some embodiments of the present disclosure, when the controller controls the rotor drive circuit, it is used to obtain a current difference according to an excitation reference current and an excitation actual current, and to obtain a pulse width modulation duty cycle of the rotor drive circuit according to the current difference through PID (proportional-integral-derivative) current regulation operation, so as to drive the rotor of the motor.

[0018] In some embodiments of the present disclosure, the stator drive circuit includes a plurality of phase bridge arms, each phase bridge arm being connected across a positive DC bus and a negative DC bus, a midpoint of each phase bridge arm being connected to a first end of a winding of the corresponding stator, and second ends of all windings of the stator being connected to a neutral point adapted to be connected to a DC charging port of the vehicle; the rotor drive circuit includes an H half-bridge arm, two ends of the H half-bridge arm being connected to the positive DC bus and the negative DC bus respectively, and a midpoint of the H half-bridge arm being connected to the rotor through a slip ring structure.

[0019] In some embodiments of the present disclosure, the oil cooling circuit comprises: an oil pump, a first end of the oil pump being connected with a first port of an oil pipe of the motor; a second plate heat exchanger, a first port of the second plate heat exchanger being connected with a second end of the oil pump, a second port of the second plate heat exchanger being connected with a second port of the oil pipe of the motor, the first port of the second plate heat exchanger being in communication with the second port of the second plate heat exchanger, a third port of the second plate heat exchanger being connected with a first end of a drive circuit thermal management pipe of the electric drive system, a second end of the drive circuit thermal management pipe being connected with a first port of the first plate heat exchanger; a first three-way valve, a first port of the first three-way valve being connected with a second port of the first plate heat exchanger, the first port of the first plate heat exchanger being in communication with the second port of the first plate heat exchanger; a water pump, a water inlet of the water pump being connected with a second port of the first three-way valve, a water outlet of the water pump being connected with a fourth port of the second plate heat exchanger, the third port of the second plate heat exchanger being in communication with the fourth port of the second plate heat exchanger; when the battery pack has a heating requirement, the first port of the first three-way valve is connected with the second port.

[0020] In some embodiments of the present disclosure, the oil cooling circuit further comprises: a radiator, a first end of the radiator being connected with the first port of the first three-way valve and the controller, when the winding temperature of the motor exceeds the electric drive temperature retention temperature, the first port of the first three-way valve is in communication with the third port of the first three-way valve to radiate heat from the motor.

[0021] In some embodiments of the present disclosure, the heat pump system comprises: a compressor, a gas-liquid separator, a first electromagnetic valve, a first electronic expansion valve, a first check valve, a second electromagnetic valve and a third electromagnetic valve; wherein an exhaust port of the compressor is connected with a first port of the first electromagnetic valve, a second port of the first electromagnetic valve is connected with a first port of a liquid pipe of the battery pack, a second port of the liquid pipe of the battery pack is connected with a first port of the first electronic expansion valve, a second port of the first electronic expansion valve is connected with an input port of the first check valve, an output port of the first check valve is connected with a first port of the second electromagnetic valve, a second port of the second electromagnetic valve is connected with a third port of the first plate heat exchanger, a fourth port of the first plate heat exchanger is connected with a first port of the third electromagnetic valve, a second port of the third electromagnetic valve is connected with a first port of the gas-liquid separator, a second port of the gas-liquid separator is connected with a back gas port of the compressor; when the temperature of the battery pack is less than a target battery pack temperature corresponding to a current environment temperature, the battery pack has a heating requirement, the first electromagnetic valve, the first electronic expansion valve, the second electromagnetic valve and the third electromagnetic valve are all in an open state.

[0022] In some embodiments of the present disclosure, the heat pump system further comprises a fourth electromagnetic valve, an outside condenser, and a second one-way valve; a first port of the fourth electromagnetic valve is connected with an output port of the first one-way valve, a second port of the fourth electromagnetic valve is connected with a first port of the outside condenser, a second port of the outside condenser is connected with an input port of the second one-way valve, and a second port of the second one-way valve is connected with a first port of the third electromagnetic valve; when the temperature of the battery pack is less than the target battery pack temperature corresponding to the current ambient temperature and the temperature of the refrigerant in the heat pump system is less than the current ambient temperature, the battery pack has a heating demand, and the first electromagnetic valve, the first electronic expansion valve, the second electromagnetic valve, the third electromagnetic valve, and the fourth electromagnetic valve are all in an open state.

[0023] In some embodiments of the present disclosure, the heat pump system further comprises a third one-way valve, an input port of the third one-way valve is connected with an output port of the second one-way valve, and an output port of the third one-way valve is connected with a second port of the first electronic expansion valve.

[0024] In some embodiments of the present disclosure, the heat pump system further comprises an inside condenser, a second electronic expansion valve, and a fifth electromagnetic valve; wherein a first port of the inside condenser is connected with an exhaust port of the compressor, a second port of the inside condenser is connected with a first port of the second electronic expansion valve and a first port of the fifth electromagnetic valve respectively, a second port of the second electronic expansion valve is connected with a first port of the fourth electromagnetic valve, and a second port of the fifth electromagnetic valve is connected with a first port of the fourth electromagnetic valve.

[0025] In some embodiments of the present disclosure, the heat pump system further comprises a third electronic expansion valve, an evaporator, and a fourth one-way valve; wherein a first port of the third electronic expansion valve is connected with a fourth port of the first plate heat exchanger and a second port of the second one-way valve, a second port of the third electronic expansion valve is connected with a first port of the evaporator, a second port of the evaporator is connected with an input port of the fourth one-way valve, and an output port of the fourth one-way valve is connected with a first port of the gas-liquid separator; the controller is further configured to determine that the cabin has a heating demand, control the third electromagnetic valve to be closed, and control the third electronic expansion valve to be opened.

[0026] In some embodiments of the present disclosure, the heat pump system further comprises a sixth electromagnetic valve, a first port of the sixth electromagnetic valve being connected with the second port of the first electromagnetic valve and the first port of the liquid path of the battery pack; when the temperature of the battery pack is greater than the normal working temperature of the battery pack, the battery pack has a cooling demand, the third electromagnetic valve, the fourth electromagnetic valve, the fifth electromagnetic valve, the sixth electromagnetic valve, the first electronic expansion valve and the second electronic expansion valve are in an open state, and the first electromagnetic valve and the second electromagnetic valve are in a closed state.

[0027] In some embodiments of the present disclosure, the controller is further configured to determine that the cabin has a refrigeration demand, control the third electronic expansion valve to be opened, and control the third electromagnetic valve to be closed, and determine that the cabin has no heating demand, control the third electromagnetic valve to be opened, and control the third electronic expansion valve to be closed.

[0028] In some embodiments of the present disclosure, the fourth electromagnetic valve is closed when the temperature of the battery pack is less than the target battery pack temperature corresponding to the current environment temperature, and the refrigerant in the heat pump system is greater than or equal to the current environment temperature.

[0029] In some embodiments of the present disclosure, the controller is further configured to determine that the cabin has no heating demand, control the third electromagnetic valve to be opened, and control the third electronic expansion valve to be closed.

[0030] In some embodiments of the present disclosure, the controller is further configured to control the motor to exit the zero-torque running state when the vehicle fails or the vehicle charging changes.

[0031] To achieve the above object, the second aspect of the present disclosure further provides a vehicle, comprising: a battery pack; and the battery thermal management system according to any one of the preceding embodiments, the battery thermal management system being connected with the liquid path of the battery pack.

[0032] The vehicle provided by the embodiments of the present disclosure is connected with the battery thermal management system according to any one of the preceding embodiments, when the battery pack has a heating demand, the battery thermal management system can control the motor to run at zero torque according to the state of the vehicle, and the rotor and the stator of the motor can heat the battery pack through the cooling liquid, so that the function is more comprehensive, the adaptation range is wider, and the utilization rate of each device in the system can be improved. Moreover, the state of the vehicle is considered, so that the vehicle can realize the function of heating the battery pack by the electric drive system in different states, thereby realizing the cooperative control of the battery pack heating and the vehicle state.

[0033] In some embodiments of the present disclosure, the vehicle further comprises: a charging and discharging circuit adapted to be connected with the battery pack, a stator driving circuit and a rotor driving circuit of the motor in the electric drive system.

[0034] In some embodiments of the present disclosure, the charging and discharging circuit comprises: a positive direct current bus connected with a positive pole of the battery pack; a negative direct current bus connected with a negative pole of the battery pack; a positive main contactor on the positive direct current bus, between one end of the stator driving circuit and a positive terminal of the battery pack, and between one end of the rotor driving circuit and the positive terminal of the battery pack, closed during charging; and a negative main contactor on the negative direct current bus, between the other end of the stator driving circuit and a negative terminal of the battery pack, and between the other end of the rotor driving circuit and the negative terminal of the battery pack, closed during charging of the battery pack.

[0035] In some embodiments of the present disclosure, the charging and discharging circuit further comprises: a bus capacitor connected across the positive direct current bus and the negative direct current bus, and located between the battery pack and the stator driving circuit; a direct current charging and discharging port, a first end of which is connected with a neutral point of the stator winding, and a second end of which is connected with the negative direct current bus; and a charging and discharging port capacitor, a first end of which is connected with the first end of the direct current charging and discharging port, and a second end of which is connected with the second end of the direct current charging and discharging port.

[0036] In some embodiments of the present disclosure, the charging and discharging circuit further comprises: a first switch on the positive direct current bus, and located between the direct current charging and discharging port and the first end of the stator driving circuit; a second switch between the second end of the direct current charging and discharging port and the second end of the charging and discharging port capacitor; and a third switch between the first end of the direct current charging and discharging port and the neutral point of the stator winding of the motor; when the vehicle is fault-free and the vehicle is in a direct charging state and the battery pack has a heating requirement, the first switch and the second switch are closed, and the third switch is open; and when the vehicle is fault-free and the vehicle is in a step-up charging state, the second switch and the third switch are closed, and the first switch is open when the battery pack has a heating requirement.

[0037] Additional aspects and advantages of the present disclosure will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0038] The above and / or additional aspects and advantages of the present disclosure will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings in which:

[0039] FIG. 1 is a block diagram of a battery thermal management system according to one embodiment of the present disclosure;

[0040] FIG. 2 is a circuit schematic diagram of a battery thermal management system according to one embodiment of the present disclosure;

[0041] FIG. 3 is a schematic diagram of circuit connections according to one embodiment of the present disclosure;

[0042] FIG. 4 is a schematic diagram of a control principle of battery pack heating according to one embodiment of the present disclosure;

[0043] FIG. 5 is a schematic diagram of a principle of coordinate transformation according to one embodiment of the present disclosure;

[0044] FIG. 6 is a block diagram of a vehicle according to one embodiment of the present disclosure;

[0045] FIG. 7 is a schematic diagram of direct charging and motor heating current flow according to one embodiment of the present disclosure;

[0046] FIG. 8 is a schematic diagram of direct charging and motor heating current flow according to another embodiment of the present disclosure

[0047] FIG. 9 is a schematic diagram of step-up charging and motor heating current flow according to one embodiment of the present disclosure;

[0048] FIG. 10 is a schematic diagram of step-up charging and motor heating current flow according to another embodiment of the present disclosure;

[0049] FIG. 11 is a flowchart of a control method for heating a battery pack by operating a motor at zero torque according to one embodiment of the present disclosure.

[0050] Figures: vehicle 1000; battery thermal management system 100; battery thermal management circuit 200; charge-discharge circuit 300; heat pump system 10, electric drive system 20, first plate exchanger 30, controller 40, direct current charging port 50; multi-phase bridge arm 11; positive direct current bus 12; negative direct current bus 13; H half-bridge arm 14; motor 1, battery pack 2, oil pump 3, second plate exchanger 4, first three-way valve 5, water pump 6, radiator 7, compressor 8, gas-liquid separator 9; stator drive circuit 21, rotor drive circuit 22, stator S, rotor F, positive main contactor K+, negative main contactor K-, bus capacitor Cn, charge-discharge port capacitor Cm, first switch K1, second switch K2, third switch K3, neutral point n1 of stator winding, first power device VT1, second power device VT2, third power device VT3, fourth power device VT4, fifth power device VT5, sixth power device VT6, seventh power device VT7, tenth power device VT10, first freewheeling diode VD1, second freewheeling diode VD2, third freewheeling diode VD3, fourth freewheeling diode VD4, fifth freewheeling diode VD5, sixth freewheeling diode VD6, seventh freewheeling diode VD7, eighth freewheeling diode VD8, ninth freewheeling diode VD9, tenth freewheeling diode VD10, first electromagnetic valve N1, second electromagnetic valve N2, third electromagnetic valve N3, fourth electromagnetic valve N4, fifth electromagnetic valve N5, sixth electromagnetic valve N6, first electronic expansion valve M1, second electronic expansion valve M2, third electronic expansion valve M3, first check valve D1, second check valve D2, third check valve D3, fourth check valve D4, outdoor condenser Q1, indoor condenser Q2, evaporator Q3. DETAILED DESCRIPTION

[0051] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0052] In the prior art, patent application No. CN201810187389.3 provides a power battery heating system and method. The system comprises a first temperature sensor, a controller and a motor, and the first temperature sensor is installed to the power battery; the controller comprises a temperature sampling unit and a heating control unit, wherein: the temperature sampling unit is used to acquire the temperature of the power battery in real time through the first temperature sensor; the heating control unit is used to control the motor to operate with zero torque using the energy provided by the power battery when the temperature of the power battery meets the preset condition. The present disclosure heats the power battery by the power motor, so that the heating of the power battery can be realized without external auxiliary heating equipment, not only reducing the cost and the complexity of system design, but also making the power battery evenly heated.

[0053] In addition, the patent application with the application number CN202110322625.X relates to the technical field of electric vehicles and provides a charging control method, a charging control device, and an electric vehicle. The control method includes: after the insulation detection of the charging pile is completed, sending a first voltage value to the charging pile; receiving the capability parameter fed back by the charging pile and controlling the first switch to be closed and the second switch to be opened; setting the charging demand voltage of the power battery as the first voltage value and entering a charging stage; obtaining the actual output charging voltage of the charging pile through a voltage detection unit; according to the size relationship between the actual output charging voltage of the charging pile and a second voltage value and the size relationship between the charging power of the power battery and a preset power, adjusting the charging demand voltage of the power battery, and at the same time, controlling the states of the first switch and the second switch. The disclosure controls the states of the first switch and the second switch, effectively and seamlessly switches the charging mode of the electric vehicle, realizes the automatic switching of the two charging modes, and enables the electric vehicle to be charged in the optimal charging mode.

[0054] In the above two existing technologies that have been disclosed, in the first patent technical solution, only the heating of the motor stator end in the parking state is considered, the rotor is not heated at the same time, the heating efficiency is low, only the motor stator generates heat in this solution, and the rotor heating technology is not mentioned. In addition, due to the hardware topology limitation of this technology, direct charging of direct current, motor locked-rotor heating of direct current boost charging, and other functions cannot be realized, the adaptation range is narrow, and the utilization rate of system devices is low. In the second patent technical solution, when the ambient temperature is low, the battery is not allowed to charge and discharge or the allowed charging and discharging current is small, and no charging and battery heating cooperative control method is mentioned. Due to the limitation of the technical algorithm itself, the scheme of assisting the battery cell heating to a predetermined temperature by the electric drive system under the charging condition cannot be realized. In view of this, the embodiment of the disclosure provides a battery thermal management system. When the battery pack has a heating demand, the motor is controlled to operate at zero torque according to the state of the vehicle, and the heat generated by the stator and / or rotor of the motor is used to heat the battery pack through the battery thermal management loop. That is, when the motor is used to heat the battery pack in the embodiment of the disclosure, the state of the vehicle is considered, and the heat generated by the stator and / or rotor of the motor can be used to heat the battery pack through the battery thermal management loop in the parking state, the direct charging state, and the boost charging state. That is, the motor rotor and stator of the embodiment of the disclosure can heat the cooling liquid to heat the battery, so that the boost charging or direct charging and motor heating cooperative control can be realized.

[0055] The battery thermal management system 100 according to the embodiment of the disclosure is described below with reference to FIGS. 1-5.

[0056] In some embodiments of the present disclosure, as shown in FIG. 1, a block diagram of a battery thermal management system 100 according to an embodiment of the present disclosure is shown. The battery thermal management system 100 includes a motor 1 and a controller 40. Specifically, the motor 1 is connected to a battery pack 2 through a battery thermal management circuit 200, where the battery thermal management circuit 200 is a circulation loop shown in FIG. 1 for connecting the battery pack 2 and the motor 1.

[0057] The controller 40 is connected to the motor 1 and the battery thermal management circuit 200, respectively, for controlling the motor 1 to operate at zero torque and causing the heat generated by a stator S and / or a rotor F of the motor 1 to heat the battery pack 2 through the battery thermal management circuit 200 when the battery pack 2 has a heating requirement according to a vehicle state.

[0058] More specifically, the battery thermal management system 100 of the embodiments of the present disclosure can be understood in conjunction with FIG. 2. FIG. 2 is a circuit schematic diagram of the battery thermal management system 100 according to an embodiment of the present disclosure. In addition, it is explained here that the dashed box shown in the figure for indicating the heat pump system 10 does not include the battery pack 2, the electric drive system 20, and the first plate exchanger 30; and the dashed box for indicating the electric drive system 20 does not include the motor 1.

[0059] The battery thermal management circuit 200 includes a heat pump system 10, an electric drive system 20, and a first plate exchanger 30. The heat pump system 10 is connected to a liquid circuit of the battery pack 2. The electric drive system 20 includes an oil liquid cooling circuit for cooling oil liquid of the motor 1, the oil liquid cooling circuit is connected to an oil liquid pipeline of the motor 1, and the oil liquid cooling circuit is connected to the heat pump system 10 and the battery pack 2 through the first plate exchanger 30, respectively. The medium circulating in the heat pump system 10 is refrigerant, so the first plate exchanger 30 is a refrigerant plate exchanger.

[0060] The controller 40 is connected to the heat pump system 10 and the electric drive system 20, respectively. The controller 40 is a vehicle control unit, for example, a VCU (Vehicle control unit, vehicle controller), for controlling the motor 1 to operate at zero torque and causing the heat generated by the stator S and / or the rotor F of the motor 1 to heat the battery pack 2 through the battery thermal management circuit 200 when the battery pack 2 has a heating requirement according to a vehicle state. It can be understood that when the motor 1 operates at zero torque, the heat generated by the motor 1 is released into the oil liquid cooling circuit, the oil liquid cooling circuit exchanges heat with the heat pump system 10 at the first plate exchanger 30, and the heat is transferred to the heat pump system 10, and the heat pump system 10 further transfers the heat generated by the motor 1 to the battery pack 2. The motor 1 is an electrically excited motor, so as to achieve the purpose of heating the battery pack 2 by the stator S and / or the rotor F of the motor 1.

[0061] Specifically, in some embodiments, the oil cooling loop includes an oil pump 3, a second plate exchanger 4, a first three-way valve 5, and a water pump 6. The first end of the oil pump 3 is connected to the first port of the oil line of the motor 1. The first port of the second plate exchanger 4 is connected to the second end of the oil pump 3, the second port of the second plate exchanger 4 is connected to the second port of the oil line of the motor 1, the first port of the second plate exchanger 4 is in communication with the second port of the second plate exchanger 4, the third port of the second plate exchanger 4 is connected to the first end of the drive circuit thermal management line of the electric drive system 20, the second end of the drive circuit thermal management line is connected to the first port of the first plate exchanger 30. The first port of the first three-way valve 5 is connected to the second port of the first plate exchanger 30, the first port of the first plate exchanger 30 is in communication with the second port of the first plate exchanger 30. The water inlet of the water pump 6 is connected to the second port of the first three-way valve 5, the water outlet of the water pump 6 is connected to the fourth port of the second plate exchanger 4, and the third port of the second plate exchanger 4 is in communication with the fourth port of the second plate exchanger 4. Specifically, as shown in FIG. 2, in the dashed box marked with the electric drive system 20, the loop formed by the solid arrows represents the cooling loop of the cooling oil in the drive circuit thermal management line, and the loop formed by the dashed arrows represents the cooling loop of the cooling oil in the oil line where the motor 1 is located. The oil cooling loop belongs to the electric drive system 20, and the second plate exchanger 4 is an electric drive plate exchanger.

[0062] When the battery pack 2 has a heating requirement, the first port of the first three-way valve 5 is connected to the second port. That is, when the motor 1 operates at zero torque to heat the battery pack 2, the heat generated by the motor 1 is actually first released into the oil line where the motor 1 is located when the heat generated by the motor 1 is transferred in the oil cooling loop. The cooling oil in the oil line exchanges heat with the cooling liquid in the drive circuit thermal management line at the second plate exchanger 4, transfers the heat to the cooling liquid loop in the drive circuit thermal management line, and then exchanges heat with the heat pump system 10 at the first plate exchanger 30. The heat is transferred to the heat pump system 10, and then the heat pump system 10 transfers the heat generated by the motor 1 to the battery pack 2, finally achieving the purpose of heating the battery pack 2 by the motor 1.

[0063] Further, in other embodiments, the oil cooling loop further includes a radiator 7, the first end of the radiator 7 is connected to the third port of the first three-way valve 5 and the controller 40, and when the winding temperature of the motor 1 exceeds the electric drive temperature, the first port of the first three-way valve 5 is connected to the third port of the first three-way valve 5 to dissipate heat from the motor 1.

[0064] It can be understood that the controller 40 can determine whether the motor 1 needs to be controlled to run at zero torque for heating the battery pack 2 through temperature detection. Specifically, the controller 40 determines that the battery heating request needs to be started by obtaining temperature data in the temperature sensor for detecting the temperature of the battery pack 2, and then sends an instruction to the electric control in the electric drive system 20, and controls the motor 1 to run at zero torque for heating through the heating control unit (software) in the electric control. Since the heat generation of the electric drive system 20 is not large enough at the initial stage of heating, the cooling liquid can be controlled to not pass through the circuit of the radiator 7 at the initial stage of zero-torque heating of the motor 1, and the cooling liquid circuit in the drive circuit thermal management pipeline exchanges heat with the heat pump system 10 at the first plate heat exchanger 30, mainly exchanging the oil temperature of the motor 1 to the first plate heat exchanger 30 through the cooling liquid, which is the internal thermal management heat flow direction of the electric drive system 20.

[0065] According to the battery thermal management system 100 provided by the embodiments of the present disclosure, based on the architecture of the heat pump system 10 and the electric drive system 20, when the battery pack 2 needs to be heated, the controller 40 controls the motor 1 to run at zero torque according to the state of the vehicle, and the rotor F and the stator S of the motor 1 can be heated by the cooling liquid to heat the battery pack 2, which realizes more comprehensive functions and wider adaptation to the environment, and has high utilization rate of devices in the whole system. In addition, the battery thermal management system 100 considers the state of the vehicle when heating the battery pack 2, so that the vehicle can realize the function of heating the battery pack 2 by the electric drive system 20 in different states, thereby realizing the cooperative control of the battery pack 2 charging and the motor 1 state.

[0066] In some embodiments of the present disclosure, the electric drive system 20 and the motor 1 of the embodiments of the present disclosure can be understood according to FIG. 3. FIG. 3 is a schematic diagram of circuit connection according to an embodiment of the present disclosure, wherein the electric drive system 20 further comprises a stator drive circuit 21 and a rotor drive circuit 22, wherein the stator drive circuit 21 and the rotor drive circuit 22 together constitute the electric control in the above embodiments. The electric drive system 20 and the controller 40 are not shown in FIG. 3.

[0067] The stator drive circuit 21 is connected with the controller 40, the stator S of the motor 1 and the charging bus of the battery pack 2 respectively, and is used for driving the stator S of the motor 1; the rotor drive circuit 22 is connected with the controller 40, the rotor F of the motor 1 and the charging bus of the battery pack 2 respectively, and is used for driving the rotor F of the motor.

[0068] Specifically, as shown in FIG. 3, the stator drive circuit 21 includes a plurality of phase bridge arms 11, each phase bridge arm being connected across a positive DC bus 12 and a negative DC bus 13, a midpoint of each phase bridge arm being connected to a first end of a winding of a corresponding stator S, second ends of all windings of the stator S being connected to a neutral point, the neutral point being adapted to be connected to a DC charging port 50 of the vehicle; the rotor drive circuit 22 includes an H half-bridge arm 14, two ends of the H half-bridge arm 14 being connected to the positive DC bus 12 and the negative DC bus 13 respectively, and a midpoint of the H half-bridge arm 14 being connected to the rotor F through a slip ring structure.

[0069] The motor 1 of the embodiment of the present disclosure can be a three-phase, five-phase, six-phase, nine-phase, twelve-phase or the like electrically excited synchronous motor, and the motor 1 can include a plurality of sets of windings. The coils of the motor 1 include x sets of windings, where x≥1 and x is an integer. Specifically, the number of phases of the xth set of windings can be m x phases, each phase winding in the xth set of windings includes n x coil branches, the n x coil branches of each phase winding are connected together to form a phase terminal, one coil branch in each phase winding in the xth set of windings is also connected to one coil branch in another phase winding to form n x connection points, where n x ≥1, m x ≥2, and m x and n x are integers. Based on this, the plurality of phase bridge arms 11 includes K groups of bridge arms, a midpoint of at least one bridge arm in a group of bridge arms is connected to a phase terminal in a set of m x phase windings, and bridge arms connected by any two phase terminals are different, where M x ≥m x , K≥x, and K and M x are integers.

[0070] Further, the plurality of phase bridge arms 11 is a reversible PWM (Pulse Width Modulation) rectifier, and the working state of each power device in the plurality of phase bridge arms 11 can be controlled by controlling the duty cycle of each power device.

[0071] Hereinafter, the disclosure embodiments are exemplified by taking the three-phase three-pole electrically excited synchronous motor shown in FIG. 3 as an example. The stator S of the three-phase motor 1 includes four sets of windings, and the three phases are A, B and C respectively; the four sets of windings are A1, B1, C1; A2, B2, C2; A3, B3, C3; A4, B5, C5 respectively. Therefore, the corresponding stator drive circuit 21, that is, the motor controller, is three-phase, and each phase bridge arm includes an upper bridge arm and a lower bridge arm, wherein the three-phase bridge arms are connected to the three-phase stator S winding coils of the motor 1 respectively. Among them, the first phase bridge arm includes the circuit structure formed by the first power device VT1 and the first freewheeling diode VD1 connected in parallel, the circuit structure formed by the second power device VT2 and the second freewheeling diode VD2 connected in parallel, and the two circuit structures are connected in series; the second phase bridge arm includes the circuit structure formed by the third power device VT3 and the third freewheeling diode VD3 connected in parallel, the circuit structure formed by the fourth power device VT4 and the fourth freewheeling diode VD4 connected in parallel, and the two circuit structures are connected in series; the third phase bridge arm includes the circuit structure formed by the fifth power device VT5 and the fifth freewheeling diode VD5 connected in parallel, the circuit structure formed by the sixth power device VT6 and the sixth freewheeling diode VD6 connected in parallel, and the two circuit structures are connected in series. The midpoint of the first phase bridge arm is connected to the coil of the three-phase stator S winding A of the motor 1, the midpoint of the second phase bridge arm is connected to the coil of the three-phase stator S winding B of the motor 1, and the midpoint of the third phase bridge arm is connected to the coil of the three-phase stator S winding C of the motor 1.

[0072] In addition, the motor 1 of the disclosure embodiments adopts a three-pole rotor, and the rotor F is supplied with power through a slip ring structure from the bus voltage. The positive electrode is connected in series to the seventh power device VT7 and the seventh freewheeling diode VD7 and the ninth freewheeling diode VD9 connected in parallel; the negative electrode is connected in series to the eighth freewheeling diode VD8, the tenth power device VT10 and the tenth freewheeling diode VD10 connected in parallel, forming an H half-bridge structure. The positive electrode of the DC charging port 50 is connected in series to the third switch K3 and connected to the midpoint n1 of the stator winding of the motor 1 through the third switch K3, and the negative electrode of the DC charging port 50 is connected in series to the second switch K2 and connected to the negative DC bus 13 through the second switch K2. The positive electrode of the charge-discharge port capacitor Cm is connected to the positive electrode of the DC charging port 50, and the negative electrode of the charge-discharge port capacitor Cm is connected to the negative DC bus 13.

[0073] The control terminals of the first power device VT1, the second power device VT2, the third power device VT3, the fourth power device VT4, the fifth power device VT5, the sixth power device VT6, the seventh power device VT7 and the tenth power device VT10 are connected to the controller 40, and the conduction of these power devices is controlled by the controller 40.

[0074] In some embodiments of the present disclosure, further understanding the heat pump system 10 of the present disclosure according to FIG. 2, the heat pump system 10 comprises a compressor 8, a gas-liquid separator 9, a first electromagnetic valve N1, a first electronic expansion valve M1, a first check valve D1, a second electromagnetic valve N2 and a third electromagnetic valve N3.

[0075] Wherein, the exhaust port of the compressor 8 is connected with the first port of the first electromagnetic valve N1, the second port of the first electromagnetic valve N1 is connected with the first port of the liquid path of the battery pack 2, the second port of the liquid path of the battery pack 2 is connected with the first port of the first electronic expansion valve M1, the second port of the first electronic expansion valve M1 is connected with the input port of the first check valve D1, the output port of the first check valve D1 is connected with the first port of the second electromagnetic valve N2, the second port of the second electromagnetic valve N2 is connected with the third port of the first plate heat exchanger 30, the fourth port of the first plate heat exchanger 30 is connected with the first port of the third electromagnetic valve N3, the second port of the third electromagnetic valve N3 is connected with the first port of the gas-liquid separator 9, and the second port of the gas-liquid separator 9 is connected with the back gas port of the compressor 8.

[0076] When the temperature of the battery pack is less than the target battery pack temperature corresponding to the current environment temperature, at this time the battery pack 2 has heating demand, it can be understood that the state is actually that the vehicle is in a fault-free state and the vehicle is in a parking state and the battery pack 2 has heating demand, then the first electromagnetic valve N1, the first electronic expansion valve M1, the second electromagnetic valve N2 and the third electromagnetic valve N3 are all in an open state.

[0077] It can be understood that when the controller 40 detects that the temperature of the battery pack is less than the target battery pack temperature corresponding to the current environment temperature, the first electromagnetic valve N1, the second electromagnetic valve N2, the third electromagnetic valve N3 and the first electronic expansion valve M1 are opened; the refrigerant passes through the compressor 8, the first electromagnetic valve N1, the battery pack 2, the first electronic expansion valve M1, the first check valve D1, the second electromagnetic valve N2, absorbs the heat generated by the electric drive system 20 through the first plate heat exchanger 30, and then returns to the compressor 8 through the third electromagnetic valve N3 and the gas-liquid separator 9, thereby achieving heating of the battery pack 2.

[0078] Further, when the controller 40 judges whether the vehicle is in a fault-free state, the faults herein include but are not limited to: CAN communication interaction abnormity among the controller 40, the heat pump system 10 and the electric drive system 20; temperature over-temperature of power switching devices in the battery pack 2, the motor 1, the stator drive circuit 21 and the rotor drive circuit 22 or sampling abnormity of temperature sensors; the water pump 6 or the oil pump 3 in the electric drive system 20 cannot be started; control abnormity of each valve in the heat pump system 10; or hardware faults detected by the controller 40 or the heat pump system 10 or the electric drive system 20.

[0079] Further, in some embodiments of the present disclosure, when the vehicle is fault-free and the vehicle is in the parking state and the battery pack 2 has heating demand, the controller 40 controls the motor 1 to run at zero torque, wherein the stator driving circuit 21 is controlled to heat the stator S and the rotor driving circuit 22 is controlled to heat the rotor F.

[0080] In some embodiments, when the controller 40 controls the stator driving circuit 21, it is configured to obtain the quadrature axis voltage and the direct axis voltage according to the target quadrature axis current, the target direct axis current, the feedback quadrature axis current and the feedback direct axis current, and to obtain the pulse width modulation duty ratio of the stator driving circuit 21 according to the quadrature axis voltage and the direct axis voltage through inverse Park transformation and pulse width modulation algorithm, so as to drive the stator S of the motor 1, wherein the target quadrature axis current is zero. In other embodiments, when the controller 40 controls the rotor driving circuit 22, it is configured to obtain the current difference according to the excitation reference current and the excitation actual current, and to obtain the pulse width modulation duty ratio of the rotor driving circuit 22 according to the current difference through PID current regulation operation, so as to drive the rotor F of the motor 1.

[0081] The following can be understood according to FIG. 4 as the control principle of the motor 1 of the present disclosure to heat the battery pack 2 when running at zero torque, FIG. 4 is a schematic diagram of the control principle of the battery pack heating according to an embodiment of the present disclosure.

[0082] The embodiments of the present disclosure take a three-phase electrically excited synchronous motor as an example, S is the stator part of the electrically excited motor 1, and F is the rotor part of the electrically excited motor 1. The motor torque equation formula is

[0083] wherein, T e represents the motor shaft end output torque, P n represents the number of motor pole pairs, L md represents the mutual inductance of the stator and rotor in the direct axis direction, i f represents the excitation current, L d represents the direct axis inductance, L q represents the quadrature axis inductance, i d represents the direct axis current, i q represents the quadrature axis current.

[0084] The parking heating control principle is as follows: to make the motor shaft end output torque T e zero, the quadrature axis current i q is zero, the direct axis current i d , the excitation current i f can be given a value within any hardware design range. The control mode is as follows: the target quadrature axis current i q_ref is given as zero to ensure that the motor shaft end has no torque output, the target direct axis current i d_ref is given, and the excitation current if_ref Target quadrature axis current i q_ref Target direct axis current i d_ref After the given, respectively, with the feedback of the cross, the direct axis current i q_fdk , i d_fdk Difference through the PID current regulator, get the quadrature axis voltage U q And the direct axis voltage U d , the direct axis voltage U d And the quadrature axis voltage U q Through the inverse Park transformation and the SVPWM (Space Vector Pulse Width Modulation) algorithm, the pulse width modulation duty cycle of each phase bridge arm is obtained.

[0085] Through the modulation of the electric control middle bridge arm, the required motor 1 current value of each phase is ultimately obtained. Among them, when measuring the current i A , i B , i C of the stator S three-phase of the motor 1, the two-phase current is usually collected first, and then the third-phase current value is calculated through Kirchhoff's law, and then the Clark transformation and Park transformation are performed to obtain the feedback of the cross, the direct axis current i q_fdk , i d_fdk . Among them, the inverse Park transformation and the Park transformation need to obtain the real-time position of the motor 1 rotor F. After the excitation current is given, the excitation actual current i f_fdk fed back by the sensor for detecting the current of the motor 1 rotor F is subtracted to obtain the current difference, and the pulse width modulation duty cycle is obtained through the PID current regulator. Through the H half-bridge modulation, the required current value of the rotor F is obtained, and the heating of the motor 1 rotor F is controlled. The rotor F and the stator S of the motor 1 produce heat at the same time, and the heating efficiency is higher. The cooling oil heat is transmitted to the cooling water in the second plate exchanger 4 through the motor 1 oil pump 3, and the cooling water transmits the heat to the refrigerant in the first plate exchanger 30, realizing the parking heating control.

[0086] Among them, the Park transformation is a synchronous rotating coordinate transformation, the two-phase stationary coordinate system is transformed into a synchronous rotating coordinate system, and generally does not contain zero-axis vector; the extended Park transformation is a synchronous rotating coordinate transformation, the two-phase stationary coordinate system is transformed into a synchronous rotating coordinate system, and contains zero-axis vector; the inverse Park transformation is the inverse transformation of the Park transformation; the Clark transformation is a stationary coordinate transformation, which transforms the N-phase axis system into a two-phase stationary coordinate system, and generally does not contain zero-axis vector; the extended Clark transformation is a stationary coordinate transformation, which transforms the N-phase axis system into a two-phase stationary coordinate system, and contains zero-axis vector; the inverse Clark transformation is the inverse transformation of the Clark transformation; the SVPWM algorithm is a space vector pulse width modulation algorithm.

[0087] The principle of coordinate transformation of the embodiment of the present disclosure can be understood according to FIG. 5, which is a schematic diagram of the principle of coordinate transformation according to one embodiment of the present disclosure, where θ is the included angle between the direct axis of the rotor of the motor for vehicle and the A-phase winding of the motor for vehicle; the direct-axis voltage U d and the quadrature-axis voltage U q are respectively the voltage of the stator S in the d-q axis coordinate system; the direct-axis current i d and the quadrature-axis current i q are respectively the current of the stator S in the d-q axis coordinate system; the direct-axis inductance L d and the quadrature-axis inductance L q are respectively the winding inductance in the d-q axis coordinate system; Rs is the resistance of the stator winding, the phase resistance; ω e is the electrical angular velocity, P n is the number of pole pairs of the motor 1, and ω e =P n ω m .

[0088] Based on the above, the embodiment of the present disclosure adopts an electrically excited synchronous motor, in the parking state, on the basis that the battery pack 1 can be heated at the stator end of the motor 1, the rotor excitation current is given a certain value, the quadrature-axis current is zero, and the direct-axis current is given a certain direct-axis current, so that the rotor F can be heated at the same time, that is, the rotor F and the stator S of the motor 1 can both realize the heating of the battery pack 2 by heating the cooling liquid, thereby improving the power of the locked-rotor heating of the motor 1 and accelerating the heating rate of the battery pack 2.

[0089] In some embodiments of the present disclosure, as shown in FIG. 2, the heat pump system 10 further comprises a fourth electromagnetic valve N4, an outdoor condenser Q1 and a second check valve D2.

[0090] The first port of the fourth electromagnetic valve N4 is connected with the output port of the first check valve D1, the second port of the fourth electromagnetic valve N4 is connected with the first port of the outdoor condenser Q1, the second port of the outdoor condenser Q1 is connected with the input port of the second check valve D2, and the second port of the second check valve D2 is connected with the first port of the third electromagnetic valve N3.

[0091] When the temperature of the battery pack 2 is less than the target temperature of the battery pack corresponding to the current environmental temperature, and the temperature of the refrigerant is less than the current environmental temperature, at this time, the battery pack 2 has a heating requirement, the first electromagnetic valve N1, the first electronic expansion valve M1, the second electromagnetic valve N2, the third electromagnetic valve N3 and the fourth electromagnetic valve N4 are all in the open state.

[0092] When the controller 40 detects that the temperature of the environment outside the vehicle is greater than the temperature of the real-time battery pack circulating refrigerant, that is, the current environment temperature is greater than the refrigerant temperature, then the first electromagnetic valve N1, the second electromagnetic valve N2, the third electromagnetic valve N3 and the fourth electromagnetic valve N4 are opened; the refrigerant passes through the compressor 8, the first electromagnetic valve N1-the battery pack 2-the first electronic expansion valve M1-the first one-way valve D1 to divide into two channels, one part of the refrigerant passes through the second electromagnetic valve N2, absorbs the heat generated by the electric drive system 20 through the first plate heat exchanger 30, and the other part absorbs heat from the environment outside the vehicle through the fourth electromagnetic valve N4-vehicle outside condenser Q1 to realize heating of the battery pack 2.

[0093] And in some other embodiments, when the temperature of the battery pack 2 is less than the target battery pack temperature corresponding to the current environment temperature, and the temperature of the refrigerant in the heat pump system 10 is greater than or equal to the current environment temperature, the fourth electromagnetic valve N4 is closed, and the refrigerant is stopped from directly absorbing heat from the outside of the vehicle.

[0094] In some other embodiments of the present disclosure, the heat pump system 10 further comprises a third one-way valve D3, the input port of the third one-way valve D3 is connected with the output port of the second one-way valve D2, and the output port of the third one-way valve D3 is connected with the second port of the first electronic expansion valve M1, wherein when the electric drive system 20 heats the battery pack 2, the third one-way valve D3 is in an open state, and the third one-way valve D3 can be used to prevent the refrigerant in the pipeline from flowing back to the liquid path of the battery pack 2.

[0095] In some other embodiments of the present disclosure, the heat pump system 10 further comprises an indoor condenser Q2, a second electronic expansion valve M2 and a fifth electromagnetic valve N5, wherein the first port of the indoor condenser Q2 is connected with the exhaust port of the compressor 8, the second port of the indoor condenser Q2 is connected with the first port of the second electronic expansion valve M2 and the first port of the fifth electromagnetic valve N5 respectively, the second port of the second electronic expansion valve M2 is connected with the first port of the fourth electromagnetic valve N4, and the second port of the fifth electromagnetic valve N5 is connected with the first port of the fourth electromagnetic valve N4.

[0096] In some other embodiments of the present disclosure, the heat pump system 10 further comprises a third electronic expansion valve M3, an evaporator Q3 and a fourth one-way valve D4; wherein the first port of the third electronic expansion valve M3 is connected with the fourth port of the first plate heat exchanger 30 and the second port of the second one-way valve D2, the second port of the third electronic expansion valve M3 is connected with the first port of the evaporator Q3, the second port of the evaporator Q3 is connected with the input port of the fourth one-way valve D4, and the output port of the fourth one-way valve D4 is connected with the first port of the gas-liquid separator 9.

[0097] The controller 40 is further configured to: determine that the cabin has a heating demand, control the third electromagnetic valve N3 to be closed, and control the third electronic expansion valve M3 to be opened; and determine that the cabin has no heating demand, control the third electromagnetic valve N3 to be opened, and control the third electronic expansion valve M3 to be closed.

[0098] If there is a heating demand in the vehicle, the third electronic expansion valve M3 is opened, the third electromagnetic valve N3 is closed, and the refrigerant passes through the third electronic expansion valve M3, the in-vehicle evaporator Q3, the fourth one-way valve D4, the gas-liquid separator 9, and then returns to the compressor 8; if there is no heating request in the vehicle, the third electromagnetic valve N3 is controlled to be opened, and the refrigerant passes through the third electromagnetic valve N3, the gas-liquid separator 9, and then returns to the compressor 8.

[0099] In some embodiments of the present disclosure, the heat pump system 10 further comprises a sixth electromagnetic valve N6, a first port of the sixth electromagnetic valve N6 being connected with a second port of the first electromagnetic valve N1 and a first port of the liquid circuit of the battery pack 2.

[0100] When it is detected that the temperature of the battery pack is greater than the normal working temperature of the battery pack 2, it is determined that the battery pack 2 has a cooling demand. It can be understood that the controller 40 can obtain temperature data of the temperature sensor for detecting the temperature of the battery pack, and when it is detected that the temperature of the battery pack is greater than the normal working temperature of the battery pack 2, it is determined that the battery heating request does not need to be opened, and then a command is sent to the heating control unit (software) in the electronic control, and the electronic control controls the motor 1 to close the zero-torque heating. The first three-way valve 5 is controlled to make the cooling liquid pass through the radiator circuit, and the electronic control cooling liquid and the cooling oil of the motor 1 exchange heat at the second plate heat exchanger 4, and then pass through the first plate heat exchanger 30, to meet the heat dissipation demand of the electric drive system 20.

[0101] The controller 40 controls the third electromagnetic valve N3, the fourth electromagnetic valve N4, the fifth electromagnetic valve N5, the sixth electromagnetic valve N6, the first electronic expansion valve M1, and the second electronic expansion valve M2 to be in an opened state, and the first electromagnetic valve N1 and the second electromagnetic valve N2 to be in a closed state. It can be understood that when the battery pack 2 needs to be cooled, the third electromagnetic valve N3, the fourth electromagnetic valve N4, the fifth electromagnetic valve N5, the sixth electromagnetic valve N6, the first electronic expansion valve M1, and the second electronic expansion valve M2 are opened, and the first electromagnetic valve N1 and the second electromagnetic valve N2 are closed, and the refrigerant passes through the in-vehicle condenser Q2, the second electronic expansion valve M2, the fifth electromagnetic valve N5, the fourth electromagnetic valve N4, the outdoor condenser Q1, and the second one-way valve D2, and part of the refrigerant passes through the third one-way valve D3, the first electronic expansion valve M1, the battery pack 2, the sixth electromagnetic valve N6, the gas-liquid separator 9, and then returns to the compressor 8, to achieve the cooling and heat dissipation demand of the battery pack 2, and the cooling and heat dissipation circuit of the battery pack 2 is separated from the heat dissipation circuit of the electric drive system 20.

[0102] In some other embodiments, the controller 40 is further configured to: determine that the cabin has a cooling demand, control the third electronic expansion valve M3 to be open, and control the third electromagnetic valve N3 to be closed; and determine that the cabin has no heating demand, control the third electromagnetic valve N3 to be open, and control the third electronic expansion valve M3 to be closed. It can be understood that when the vehicle has a cooling demand, the third electronic expansion valve M3 is opened and the third electromagnetic valve N3 is closed, and a part of the refrigerant passes through the third electronic expansion valve M3, the in-cabin evaporator Q3, the fourth one-way valve D4, the gas-liquid separator 9, and returns to the compressor 8; when the vehicle has no cooling demand, the third electromagnetic valve N3 is opened, and the refrigerant passes through the third electromagnetic valve N3 and the gas-liquid separator 9, and returns to the compressor 8.

[0103] Based on the above, the battery thermal management system 100 of the embodiments of the present disclosure is based on the architecture of the heat pump system 10 and the electric drive system 20. When the battery pack 2 has a heating demand, the controller 40 controls the motor 1 to perform zero-torque operation according to the state of the vehicle, and the rotor S and the stator F of the motor 1 can heat the cooling liquid to heat the battery pack 2. At the same time, the state of the vehicle is considered, so that the vehicle can realize the function of heating the battery pack 2 by the electric drive system 20 in the charging or non-charging state, thereby realizing the cooperative control of the battery pack 2 charging and the motor 1 heating.

[0104] In some other embodiments of the present disclosure, the controller 40 is further configured to control the motor 1 to exit the zero-torque operation state when the vehicle has a fault or the vehicle charging changes. For example, when the motor 1 is in the zero-torque heating control strategy, the motor 1 exits the zero-torque heating control of the motor 1 by the electric control if the vehicle has a fault or is in a parking state or the charging changes (power off, driving, etc.). Alternatively, when the motor 1 is in the zero-torque heating control strategy, the controller 40 is further configured to exit the zero-torque heating control of the motor 1 by the electric control when it is determined that the temperature of the battery pack is greater than or equal to the target battery pack temperature corresponding to the current environment temperature, that is, the heating of the battery pack 2 is completed.

[0105] To achieve the above purpose, the second aspect of the present disclosure further provides a vehicle 1000. FIG. 6 is a block diagram of the vehicle 1000 according to an embodiment of the present disclosure, wherein the vehicle 1000 comprises the battery pack 2 and the battery thermal management system 100 of any one of the above embodiments, and the battery thermal management system 100 is connected with the liquid circuit of the battery pack 2.

[0106] In particular, the vehicle 1000 of the embodiments of the present disclosure can also be understood according to FIG. 3, wherein the vehicle 1000 further comprises a charging and discharging circuit 300 connected with the battery pack 2, the stator drive circuit 21 and the rotor drive circuit 22 of the motor 1 in the electric drive system 20. In particular, the charging and discharging circuit 300 comprises a positive DC bus 12 connected with the positive pole of the battery pack 2, a negative DC bus 13 connected with the negative pole of the battery pack 2, a positive main contactor K+ and a negative main contactor K-. The charging and discharging circuit 300, the positive DC bus 12 and the negative DC bus 13 are not shown in FIG. 3.

[0107] The positive main contactor K+ is located on the positive DC bus 12, between one end of the stator drive circuit 21 and the positive pole of the battery pack 2, and between one end of the rotor drive circuit 22 and the positive pole of the battery pack 2, and is closed during charging. The negative main contactor K- is located on the negative DC bus 13, between the other end of the stator drive circuit 21 and the negative pole of the battery pack 2, and between the other end of the rotor drive circuit 22 and the negative pole of the battery pack 2, and is closed during charging of the battery pack 2. That is, the battery pack 2 is connected to the DC bus of the motor controller, i.e., the stator drive circuit 21 and the rotor drive circuit 22, through the positive main contactor K+ and the negative main contactor K-.

[0108] In addition, the charging and discharging circuit 300 further comprises a bus capacitor Cn, a charging and discharging port capacitor Cm and a DC charging and discharging port 50. The bus capacitor Cn is connected across the positive DC bus 12 and the negative DC bus 13, and is located between the battery pack 2 and the stator drive circuit 21. The first end of the DC charging and discharging port 50 is connected with the neutral point n1 of the stator winding, and the second end of the DC charging and discharging port 50 is connected with the negative DC bus 13. The first end of the charging and discharging port capacitor Cm is connected with the first end of the DC charging and discharging port 50, and the second end of the charging and discharging port capacitor Cm is connected with the second end of the DC charging and discharging port 50. That is, the positive pole of the charging and discharging port capacitor Cm is connected to the positive pole of the DC charging and discharging port 50, and the negative pole of the charging and discharging port capacitor Cm is connected to the negative DC bus 13.

[0109] In some embodiments of the present disclosure, as shown in FIG. 3, the charge-discharge circuit 300 further comprises a first switch K1, a second switch K2 and a third switch K3. The first switch K1 is located on the positive DC bus 12, and the first switch K1 is located between the DC charge-discharge port 50 and the first end of the stator drive circuit 21, the second switch K2 is located between the second end of the DC charge-discharge port 50 and the second end of the charge-discharge port capacitor Cm, and the third switch K3 is located between the first end of the DC charge-discharge port 50 and the neutral point n1 of the stator winding of the motor 1. That is, the third switch K3 is connected to the outgoing neutral line of the motor, that is, the neutral point n1 of the stator winding, as a positive series switch of the DC charge-discharge port 50 circuit, and the second switch K2 is connected to the negative DC bus 13 as a negative series switch of the DC charge-discharge port 50 circuit.

[0110] In some embodiments of the present disclosure, when the vehicle 1000 is fault-free and the vehicle 1000 is in a direct charging state and the battery pack 2 has a heating requirement, the first switch K1 and the second switch K2 are closed, and the third switch K3 is open.

[0111] Specifically, the analysis of the present embodiment of the present disclosure when the vehicle 1000 is fault-free and the vehicle 1000 is in a direct charging state and the battery pack 2 has a heating requirement can be understood in combination with FIG. 7 and FIG. 8. FIG. 7 is a schematic diagram of the current flow direction of direct charging and motor heating according to an embodiment of the present disclosure; and FIG. 8 is a schematic diagram of the current flow direction of direct charging and motor heating according to another embodiment of the present disclosure.

[0112] In some embodiments of the present disclosure, when the vehicle 1000 is fault-free and the vehicle 1000 is in a direct charging state and the battery pack 2 has a heating requirement, the controller 40 controls the motor 1 to operate at zero torque, wherein the stator drive circuit 21 is controlled to heat the stator S and the rotor drive circuit 22 is controlled to heat the rotor F.

[0113] Specifically, as shown in FIG. 7 or FIG. 8, the solid arrow represents the current direction of the battery pack 2 supplying power to the motor 1, and the dashed arrow represents the current direction of the battery pack 2 being directly charged.

[0114] For the charging process, when the DC gun of the charging pile is inserted into the DC charge-discharge port 50, the controller 40 first determines whether boost charging is required, and if not, direct charging is performed, the first switch K1, the second switch K2, the positive main contactor K+ and the negative main contactor K- are controlled to be attracted, and the third switch K3 is controlled to be open. The external charging pile supplies power to the battery pack 2 through the DC charge-discharge port 50, the positive DC bus 12 and the negative DC bus 13.

[0115] For the process of heating the battery pack 2, it can be determined whether the battery pack 2 needs to be heated according to the method of the above embodiment. If it is determined that the motor 1 needs to be controlled to run at zero torque to heat the battery pack 2, the direct charging and heating function is executed. The controller 40 controls the first power device VT1, the fourth power device VT4, the sixth power device VT6, the seventh power device VT7 and the tenth power device VT10 to be turned on, and controls the second power device VT2, the third power device VT3 and the fifth power device VT5 to be turned off, so that the battery pack 2 provides current for the rotor F and the stator S of the motor 1, to realize that the rotor F and the stator S of the motor 1 generate heat at the same time, thereby realizing the cooperative control of the direct charging and the heating of the motor 1.

[0116] In addition, in some other embodiments, when the vehicle 1000 is fault-free and the vehicle 1000 is in the boost charging state, when the battery pack 2 has a heating demand, the second switch K2 and the third switch K3 are closed, and the first switch K1 is open.

[0117] Specifically, the analysis of the vehicle 1000 fault-free and the vehicle 1000 in the direct charging state and the battery pack 2 having a heating demand in the embodiments of the present disclosure can be understood in combination with FIG. 9 and FIG. 10. FIG. 9 is a schematic diagram of boost charging and motor heating current flow according to one embodiment of the present disclosure, and FIG. 10 is a schematic diagram of boost charging and motor heating current flow according to another embodiment of the present disclosure.

[0118] In some embodiments of the present disclosure, when the vehicle 1000 is fault-free and the vehicle 1000 is in the boost charging state, when the battery pack 2 has a heating demand, the controller 40 controls the motor 1 to run at zero torque, wherein the stator S is controlled to store energy by controlling the stator drive circuit 21, and the rotor F is controlled to generate heat by controlling the rotor drive circuit 22.

[0119] Specifically, as shown in FIG. 9 or FIG. 10, the solid arrow represents the current direction of the battery pack 2 supplying power to the motor 1, and the dashed arrow represents the current direction of the battery pack 2 being boost charged.

[0120] For the charging process, when the DC gun of the charging pile is inserted into the DC charging and discharging port 50, the controller 40 first determines whether boost charging is needed, and if so, performs boost charging, and then executes the boost charging and heating functions. The second switch K2, the third switch K3, the positive main contactor K+ and the negative main contactor K- are controlled to be attracted by the controller 40, and the first switch K1 is controlled to be turned off. The charging demand target voltage Chrg_Volt sent by the controller 40 is received, and the voltage Cm_Volt of the charging and discharging port capacitor Cm is collected in real time. The difference between Chrg_Volt and Cm_Volt is adjusted by a PID voltage regulator, and the PWM duty cycle of each phase bridge arm is obtained by a SPWM (Sinusoidal Pulse Width Modulation) algorithm, wherein the duty cycles of the three-phase bridge arms are the same. As shown in FIG. 9, during the energy storage process of the stator S, the controller 40 controls the second power device VT2, the fourth power device VT4 and the sixth power device VT6 to be turned on, and controls the first power device VT1, the third power device VT3 and the fifth power device VT5 to be turned off. As shown in FIG. 10, when it is determined that the energy storage of the stator S is completed according to the voltage Cm_Volt of the charging and discharging port capacitor Cm, the controller 40 controls the first power device VT1, the third power device VT3 and the fifth power device VT5 to be turned on, and controls the second power device VT2, the fourth power device VT4 and the sixth power device VT6 to be turned off, so as to release the energy stored in the stator S to the battery pack 2, thereby achieving the purpose of boost charging the battery pack 2. In FIGS. 9 and 10, the charging demand target voltage Chrg_Volt and the voltage Cm_Volt of the charging and discharging port capacitor Cm are not shown.

[0121] As shown in FIGS. 9 and 10, for the process of heating the battery pack 2, it can be determined whether the battery pack 2 needs to be heated according to the method of the above embodiment. If it is determined that the motor 1 needs to be controlled to heat the battery pack 2, the controller 40 controls the seventh power device VT7 and the tenth power device VT10 to be turned on, so as to provide current to the rotor F of the motor 1 by the battery pack 2. Specifically, the excitation current i f_ref The given value is subtracted from the actual excitation current i f_fdk The difference is adjusted by a PID current regulator, the PWM duty cycle is calculated, and the required current value of the rotor F is obtained by the action of the H half-bridge modulation, so as to control the rotor F of the motor 1 to generate heat, thereby realizing the cooperative control of boost charging and motor 1 heating.

[0122] Based on the above, the motor 1 adopted by the present disclosure can perform cooperative control of boosting or directly connecting charging of the battery pack 2 and heating of the motor 1. When boosting charging, the stator S part adopts boosting control, and the rotor F adopts a given H half-bridge PWM direct current control rotor winding heat production; and when directly connecting charging, heating control is performed on the stator S and rotor F windings under the condition of ensuring zero torque of the whole vehicle. Thus, cooperative control of motor 1 locked-rotor heating during direct current direct charging and direct current boosting charging can be realized, the function is comprehensive, the adaptive environment range is relatively wide, and the utilization rate of each device in the system can be improved. In addition, through the cooperative control of battery pack 2 charging and motor 1 heating, the heat pump system 10 relies on the direct heating of the refrigerant to absorb the heat of the electric drive system 20 to heat the battery pack 2, and at the same time, passenger compartment heating can be realized, and the charging efficiency is improved.

[0123] According to the vehicle 1000 of the embodiment of the present disclosure, by connecting the battery thermal management system 100 of any one of the above embodiments with the liquid circuit of the battery pack 2, when the battery pack 2 has a heating requirement, the battery thermal management system 100 can control the motor 2 to operate at zero torque according to the state of the vehicle 1000, and the rotor S and the stator F of the motor 2 can heat the battery pack 2. Moreover, since the state of the vehicle 1000 is considered, the vehicle 1000 can realize the function of heating the battery pack 2 by the electric drive system 20 in the charging or non-charging state, so that cooperative control of battery pack 2 charging and motor 1 heating can be performed.

[0124] Further, the process of controlling the motor to operate at zero torque to heat the battery pack when the battery pack needs to be heated can be understood according to FIG. 2 and FIG. 11. FIG. 11 is a flowchart of a control method for heating the battery pack by the motor operating at zero torque according to an embodiment of the present disclosure, which includes steps S101-S110, and the details are as follows.

[0125] S101, it is judged whether the whole vehicle is fault-free and in the parking or charging state, if the judgment result is yes, step S102 is executed, and if the judgment result is no, step S103 is executed.

[0126] S102, the controller receives a temperature sampling value T1. The temperature sampling value T1 is the temperature of the battery pack, which is detected by a temperature sensor for detecting the temperature of the battery pack and uploaded to the controller.

[0127] S103, it is judged whether the motor is in a zero-torque heating control strategy, if the judgment result is yes, step S109 is executed, and if the judgment result is no, it is returned to be judged again.

[0128] S104, it is judged whether T1 < T1ref is met, if the judgment result is yes, step S105 is executed, if the judgment result is no, step S103 is executed. Wherein, T1 is the temperature of the battery pack, T1ref is the target battery pack temperature corresponding to the current ambient temperature.

[0129] S105, the controller sends a heating instruction to the electric control.

[0130] It can be understood that when T1 < T1ref, it is determined that the current battery pack needs to be assisted by the electric drive system. If T1 is greater than or equal to T1ref, the battery currently does not need to be assisted by the motor. In particular, when the vehicle has a fault or is in a parking state or the charging changes (power withdrawal, driving, etc.), or T1 ≥ T1ref, if the motor is in a zero torque heating control strategy, step S109 is executed, and the electric control exits the zero torque heating control of the motor.

[0131] S106, the motor zero torque control strategy is started. This step is executed by the heating control unit (software) in the electric control.

[0132] S107, it is judged whether T2 < T2ref is met, if the judgment result is yes, step S108 is executed, if the judgment result is no, step S109 is executed. Wherein, T2 is the winding temperature of the motor, and T2ref is the electric drive temperature preservation temperature.

[0133] Further, if the motor is in a zero torque heating control strategy, it is necessary to judge whether the temperature T2 sampled by the motor winding sensor is greater than the electric drive temperature preservation temperature value T2ref, if T2 is less than T2ref, the judgment flow is exited, and the motor remains in the zero torque heating state.

[0134] S108, the water pump in the electric drive system and the first port and the third port circuit of the first three-way valve are started. This is because in a low temperature environment, the motor starts the zero torque heating early, and the electric drive winding temperature is also relatively low, if the electric drive system radiator is started to cool, heat loss will be caused.

[0135] S110, it is judged whether T3 > T1 is met, if the judgment result is yes, step S111 is executed, if the judgment result is no, step S109 is executed. Wherein, T3 is the temperature sampled by the circulating water temperature sensor of the electric drive system 20.

[0136] It can be understood that after the motor 1 remains in the zero-torque heating state and the water pump 6 and the oil pump 3 in the electric drive system 20 are turned on, the water temperature in the circulation of the electric drive system 20 is increased, and it is judged whether the temperature T3 sampled by the water temperature sensor in the circulation of the electric drive system 20 is greater than the temperature T1 sampled by the current battery system temperature sensor, that is, the temperature of the battery pack 2. If T3 is greater than T1, the first electromagnetic valve N1, the fourth electromagnetic valve N4, and the second electromagnetic valve N2 are opened, and the sixth electromagnetic valve N6 and the fifth electromagnetic valve N5 are closed. According to the temperature difference between the temperature T1 of the battery pack and the water temperature T3 in the circulation of the electric drive system, the duty cycle of the PWM of the first electronic expansion valve M1 is given. The circulating water in the electric drive system 20 is heated by the cold medium of the heat pump system 10 to heat the circulating water of the power battery system, so as to realize the heat transfer from the electric drive system 20 to the battery pack 2. At the same time, after the cold medium in the heat pump system 10 is heated, the excess heat can be used to heat and insulate the passenger compartment, so as to realize the efficient use of heat. If the electric drive circulation water temperature T3 is less than or equal to the temperature T1 of the battery pack, the judgment process is exited, the motor 1 remains in the zero-torque heating state, the fifth electromagnetic valve N5, the fourth electromagnetic valve N4, the second electromagnetic valve N2, and the third electromagnetic valve N3 are opened, and the first electronic expansion valve M1 is closed. This is because the battery has a resistance characteristic, and during the charging and discharging process, the temperature of the battery pack will also gradually rise. If the first electronic expansion valve M1 is opened and the duty cycle of the PWM of the first electronic expansion valve M1 is given, the power battery will take away the heat generated by the battery pack 2, causing the problem of low heating efficiency of the battery.

[0137] S111, the water pump in the electric drive system and the first port and the second port of the first three-way valve are turned on.

[0138] S109, the motor zero-torque heating control strategy is closed.

[0139] Based on the above, the vehicle 1000 of the embodiment of the present disclosure can perform cooperative control of voltage boosting or direct charging and motor 1 heating. In the voltage boosting charging, the stator S part adopts voltage boosting control, and the rotor F adopts given H half-bridge PWM direct current control to generate heat in the rotor winding; and in the direct charging, the stator S and the rotor F winding are both heated under the condition of ensuring zero torque of the whole vehicle. Thus, the cooperative control of motor 1 locked-rotor heating in direct current direct charging and direct current voltage boosting charging can be realized, the function is comprehensive, the adaptive environment range is relatively wide, and the utilization rate of each device in the system can be improved. In addition, through the cooperative control of battery pack 2 charging and motor 1 heating, the heat pump system 10 can absorb the heat of the electric drive system 20 to heat the battery pack 2, and at the same time, the heating of the passenger compartment can be realized, and the charging efficiency is improved.

[0140] The other configurations and operations of the vehicle 1000 and the battery thermal management system 100 according to the embodiment of the present disclosure are known to those skilled in the art, and will not be described in detail here.

[0141] In the description of the disclosure, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the disclosure. In the description of the disclosure, the exemplary description of the above terms does not necessarily mean the same embodiment or example.

[0142] Although the embodiments of the disclosure have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the disclosure, and the scope of the disclosure is defined by the claims and their equivalents.

Claims

1. A battery thermal management system (100), characterized by, Comprising: a motor (1) connected with a battery pack (2) through a battery thermal management circuit (200); and a controller (40) connected with the motor (1) and the battery thermal management circuit (200) respectively, the controller (40) is configured to control the motor (1) to run at zero torque and make the stator (S) and / or the rotor (F) of the motor (1) generate heat to heat the battery pack (2) through the battery thermal management circuit (200) when the battery pack (2) has heating demand according to the state of the vehicle (1000).

2. The battery thermal management system (100) of claim 1, wherein, The battery thermal management circuit (200) comprises: a heat pump system (10) connected with the liquid circuit of the battery pack (2); an electric drive system (20) comprising an oil liquid cooling circuit for cooling the motor (1), the oil liquid cooling circuit is connected with the oil liquid pipeline of the motor (1); and a first plate exchanger (30), the oil liquid cooling circuit is connected with the heat pump system (10) and the battery pack (2) through the first plate exchanger (30) respectively.

3. The battery thermal management system (100) of claim 2, wherein, The electric drive system (20) further comprises: a stator drive circuit (21) connected with the controller (40), the stator (S) of the motor (1) and the charging bus of the battery pack (2) respectively, for driving the stator (S) of the motor (1); a rotor drive circuit (22) connected with the controller (40), the rotor (F) of the motor (1) and the charging bus of the battery pack (2) respectively, for driving the rotor (F) of the motor (1).

4. The battery thermal management system (100) according to claim 3, wherein when the vehicle (1000) is fault-free, the vehicle (1000) is in a parking state and the battery pack (2) has heating demand, the controller (40) controls the motor (1) to run at zero torque, wherein the stator (S) is heated by controlling the stator drive circuit (21) and the rotor (F) is heated by controlling the rotor drive circuit (22).

5. The battery thermal management system (100) according to claim 3 or 4, wherein when the vehicle (1000) is fault-free, the vehicle (1000) is in a direct charging state and the battery pack (2) has heating demand, the controller (40) controls the motor (1) to run at zero torque, wherein the stator (S) is heated by controlling the stator drive circuit (21) and the rotor (F) is heated by controlling the rotor drive circuit (22).

6. The battery thermal management system (100) according to claim 4 or 5, wherein The controller (40) is configured to obtain a quadrature axis voltage and a direct axis voltage according to a target quadrature axis current, a target direct axis current, a feedback quadrature axis current and a feedback direct axis current when controlling the stator drive circuit (21), and obtain a pulse width modulation duty cycle of the stator drive circuit (21) according to the quadrature axis voltage and the direct axis voltage through inverse Park transformation and a pulse width modulation algorithm to drive the stator (S) of the motor (1), wherein the target quadrature axis current is zero.

7. The battery thermal management system (100) according to any one of claims 3-6, characterized by, When the vehicle (1000) is fault-free and in a boost charging state, the controller (40) controls the motor (1) to operate at zero torque when there is a heating demand for the battery pack (2), wherein the stator (S) is controlled by the stator drive circuit (21) to store energy and the rotor (F) is controlled by the rotor drive circuit (22) to generate heat.

8. The battery thermal management system (100) of claim 6 or 7, wherein, The controller (40) is configured to obtain a current difference according to an excitation reference current and an excitation actual current when controlling the rotor drive circuit (22), and obtain a pulse width modulation duty cycle of the rotor drive circuit according to the current difference through PID current regulation operation to drive the rotor (F) of the motor (1).

9. The battery thermal management system (100) of any one of claims 3-7, wherein, The stator drive circuit (21) comprises a multi-phase bridge arm (11), each phase bridge arm is connected across a positive DC bus (12) and a negative DC bus (13), and a midpoint of each phase bridge arm is connected to a first end of a winding of a corresponding stator (S), and second ends of all windings of the stator (S) are connected to a neutral point which is adapted to be connected to a DC charging port (50) of a vehicle (1000); The rotor drive circuit (22) comprises an H half-bridge arm (14), two ends of the H half-bridge arm (14) are connected to the positive DC bus (12) and the negative DC bus (13) respectively, and a midpoint of the H half-bridge arm (14) is connected to the rotor (F) through a slip ring structure.

10. The battery thermal management system (100) according to any one of claims 2-9, characterized by, The oil cooling circuit comprises: An oil pump (3), a first end of the oil pump (3) is connected to a first port of the oil pipeline of the motor (1); A second plate exchanger (4), a first end of the second plate exchanger (4) is connected to a second end of the oil pump (3), a second end of the second plate exchanger (4) is connected to a second port of the oil pipeline of the motor, a third end of the second plate exchanger (4) is connected to a first end of a drive circuit thermal management pipeline of the electric drive system, and a second end of the drive circuit thermal management pipeline is connected to a first port of the first plate exchanger (30). a first three-way valve (5) having a first port connected with a second port of the first plate heat exchanger (30), and a first port of the first plate heat exchanger (30) being communicated with the second port of the first plate heat exchanger (30); a water pump (6) having a water inlet connected with the second port of the first three-way valve (5), and a water outlet connected with a fourth port of the second plate heat exchanger (4), and a third port of the second plate heat exchanger (4) being communicated with the fourth port of the second plate heat exchanger (4); when the battery pack (2) has a heating demand, the first port of the first three-way valve (5) is communicated with the second port.

11. The battery thermal management system (100) of claim 10, wherein, The oil cooling circuit further comprises: a radiator (7) having a first end connected with the third port of the first three-way valve (5) and the controller (40), and when the winding temperature of the motor exceeds the electric drive temperature, the first port of the first three-way valve (5) is communicated with the third port of the first three-way valve (5) to cool the motor (1).

12. The battery thermal management system (1) according to any one of claims 2-11, characterized by, The heat pump system (10) comprises: a compressor (8), a gas-liquid separator (9), a first electromagnetic valve (N1), a first electronic expansion valve (M1), a first check valve (D1), a second electromagnetic valve (N2) and a third electromagnetic valve (N3); wherein the exhaust port of the compressor (8) is connected with the first port of the first electromagnetic valve (N1), the second port of the first electromagnetic valve (N1) is connected with the first port of the liquid path of the battery pack (2), the second port of the liquid path of the battery pack (2) is connected with the first port of the first electronic expansion valve (M1), the second port of the first electronic expansion valve (M1) is connected with the input port of the first check valve (D1), the output port of the first check valve (D1) is connected with the first port of the second electromagnetic valve (N2), the second port of the second electromagnetic valve (N2) is connected with the third port of the first plate heat exchanger, the fourth port of the first plate heat exchanger is connected with the first port of the third electromagnetic valve (N3), the second port of the third electromagnetic valve (N3) is connected with the first port of the gas-liquid separator (9), and the second port of the gas-liquid separator (9) is connected with the back gas port of the compressor (8); when the temperature of the battery pack (2) is less than the target battery pack temperature corresponding to the current environment temperature, the battery pack (2) has a heating demand, and the first electromagnetic valve (N1), the first electronic expansion valve (M1), the second electromagnetic valve (N2) and the third electromagnetic valve (N3) are all in an open state.

13. The battery thermal management system (100) of claim 12, wherein, The heat pump system (10) further comprises: a fourth electromagnetic valve (N4), an outdoor condenser (Q1) and a second check valve (D2); The first port of the fourth electromagnetic valve (N4) is connected with the output port of the first check valve (D1), the second port of the fourth electromagnetic valve (N4) is connected with the first port of the outside condenser (Q1), the second port of the outside condenser (Q1) is connected with the input port of the second check valve (D2), and the second port of the second check valve (D2) is connected with the first port of the third electromagnetic valve (N3); When the temperature of the battery pack (2) is less than the target battery pack (2) temperature corresponding to the current environment temperature, and the refrigerant temperature in the heat pump system (10) is less than the current environment temperature, the battery pack (2) has a heating demand, and the first electromagnetic valve (N1), the first electronic expansion valve (M1), the second electromagnetic valve (N2), the third electromagnetic valve (N3) and the fourth electromagnetic valve (N4) are all in an open state.

14. The battery thermal management system (100) of claim 13, wherein, The heat pump system (10) further comprises: The input port of the third check valve (D3) is connected with the output port of the second check valve (D2), and the output port of the third check valve (D3) is connected with the second port of the first electronic expansion valve (M1).

15. The battery thermal management system (100) according to claim 13 or 14, characterized by, The heat pump system (10) further comprises: An inside condenser (Q2), a second electronic expansion valve (M2) and a fifth electromagnetic valve (N5); The first port of the inside condenser (Q2) is connected with the exhaust port of the compressor (8), the second port of the inside condenser (Q2) is connected with the first port of the second electronic expansion valve (M2) and the first port of the fifth electromagnetic valve (N5) respectively, the second port of the second electronic expansion valve (M2) is connected with the first port of the fourth electromagnetic valve (N4), and the second port of the fifth electromagnetic valve (N5) is connected with the first port of the fourth electromagnetic valve (N4).

16. The battery thermal management system (100) of claim 15, wherein, The heat pump system (10) further comprises: A third electronic expansion valve (M3), an evaporator (Q3) and a fourth check valve (D4); The first port of the third electronic expansion valve (M3) is connected with the fourth port of the first plate exchanger (30) and the second port of the second check valve (D2), the second port of the third electronic expansion valve (M3) is connected with the first port of the evaporator (Q3), the second port of the evaporator (Q3) is connected with the input port of the fourth check valve (D4), and the output port of the fourth check valve (D4) is connected with the first port of the gas-liquid separator (9); The controller (40) is further configured to determine that the cabin has a heating demand, control the third electromagnetic valve (N3) to be closed, and control the third electronic expansion valve (M3) to be opened.

17. The battery thermal management system (100) of claim 16, wherein, The heat pump system (10) further comprises: A sixth electromagnetic valve (N6), the first port of the sixth electromagnetic valve (N6) is connected with the second port of the first electromagnetic valve (N1) and the first port of the liquid path of the battery pack (2); When the temperature of the battery pack (2) is greater than the normal working temperature of the battery pack (2), the battery pack (2) has a cooling demand, and the third electromagnetic valve (N3), the fourth electromagnetic valve (N4), the fifth electromagnetic valve (N5), the sixth electromagnetic valve (N6), the first electronic expansion valve (M1), and the second electronic expansion valve (M2) are all in an open state, and the first electromagnetic valve (N1) and the second electromagnetic valve (N2) are in a closed state.

18. The battery thermal management system (100) of claim 17, wherein, The controller (40) is further configured to: determine that the cabin has a refrigeration demand, control the third electronic expansion valve (M3) to be opened, and control the third electromagnetic valve (N3) to be closed, and determine that the cabin has no heating demand, control the third electromagnetic valve (N3) to be opened, and control the third electronic expansion valve (M3) to be closed.

19. The battery thermal management system (100) according to any one of claims 13-17, characterized by, When the temperature of the battery pack (2) is less than the target battery pack (2) temperature corresponding to the current environment temperature, and the refrigerant temperature in the heat pump system (10) is greater than or equal to the current environment temperature, the fourth electromagnetic valve (N4) is closed.

20. The battery thermal management system (100) according to any one of claims 16-18, characterized by, The controller (40) is further configured to: determine that the cabin has no heating demand, control the third electromagnetic valve (N3) to be opened, and control the third electronic expansion valve (M3) to be closed.

21. The battery thermal management system (100) according to any one of claims 1-20, characterized by, The controller is further configured to control the motor to exit the zero-torque operating state when the vehicle (1000) fails or the charging of the vehicle (1000) changes.

22. A vehicle (1000), characterized by Comprise: a battery pack (2); and The battery thermal management system (100) according to any one of claims 1-21, wherein the battery thermal management system (100) is connected with a liquid circuit of the battery pack (2).

23. The vehicle (1000) according to claim 22, characterized by The vehicle (1000) further comprises: a charging and discharging circuit (300) adapted to be connected with the battery pack (2), a stator drive circuit (21) and a rotor drive circuit (22) of the motor (1) in the electric drive system.

24. The vehicle (1000) according to claim 23, characterized by The charging and discharging circuit (300) comprises: a positive direct current bus (12) connected with a positive electrode of the battery pack (2); a negative direct current bus (13) connected with a negative electrode of the battery pack (2); a positive main contactor (K+) located on the positive direct current bus (12), between one end of the stator drive circuit (21) and a positive electrode terminal of the battery pack (2), and between one end of the rotor drive circuit (22) and the positive electrode terminal of the battery pack (2), and closed during charging; a negative main contactor (K-) located on the negative direct current bus (13), between the other end of the stator drive circuit (21) and a negative electrode terminal of the battery pack (2), and between the other end of the rotor drive circuit (22) and the negative electrode terminal of the battery pack (2), and closed during charging of the battery pack (2).

25. The vehicle (1000) according to claim 24, characterized by The charging and discharging circuit (300) further comprises: a bus capacitor (Cn) connected across the positive DC bus (12) and the negative DC bus (13), and located between the battery pack (2) and the stator drive circuit (21); a DC charging and discharging port (50), a first end of the DC charging and discharging port (50) being connected to a neutral point (n1) of the stator winding, and a second end of the DC charging and discharging port (50) being connected to the negative DC bus (13); a charging and discharging port capacitor (Cm), a first end of the charging and discharging port capacitor (Cm) being connected to the first end of the DC charging and discharging port (50), and a second end of the charging and discharging port capacitor (Cm) being connected to the second end of the DC charging and discharging port (50).

26. The vehicle (1000) according to claim 25, characterized by The charging and discharging circuit (300) further comprises: a first switch (K1), the first switch (K1) being located on the positive DC bus (12), and the first switch (K1) being located between the DC charging and discharging port (50) and a first end of the stator drive circuit (21); a second switch (K2), the second switch (K2) being located between a second end of the DC charging and discharging port (50) and a second end of the charging and discharging port capacitor (Cm); a third switch (K3), the third switch (K3) being located between the first end of the DC charging and discharging port (50) and the neutral point (n1) of the stator winding of the motor (1); when the vehicle (1000) is fault-free and the vehicle (1000) is in a direct connection charging state and the battery pack (2) has a heating requirement, the first switch (K1) and the second switch (K2) are closed, and the third switch (K3) is open; and when the vehicle (1000) is fault-free and the vehicle (1000) is in a step-up charging state, when the battery pack (2) has a heating requirement, the second switch (K2) and the third switch (K3) are closed, and the first switch (K1) is open.

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