Vehicle thermal management system, drive unit and electric vehicle

Abstract

The present application relates to the field of electric vehicles, in particular to a vehicle thermal management system, a drive, and an electric vehicle. The thermal management system includes: a motor configured to drive and operate an air conditioner compressor, N resistor branches, and a driver configured to drive and operate the motor and resistors on the N resistor branches. The driver includes a control circuit and an inverter circuit. The control circuit is configured to control the inverter circuit to output an alternating current to the motor to drive and rotate the motor. The control circuit is further configured to control the inverter circuit to output a current to the N resistor branches such that the resistors on the N resistor branches generate heat. Thus, the motor and the heating resistors are driven by using a single driver. This reduces the cost of the thermal management system and saves space in the thermal management system.

Description

[Technical field]

[0001] The present application relates to the field of electric vehicles, in particular to vehicle thermal management systems, drives, and electric vehicles. [Background technology]

[0002] A thermal management system (TMS) is required to control the temperature of components such as the vehicle passenger compartment and drive system (e.g., the engine in a conventional fuel vehicle and the battery in an electric vehicle) for vehicle comfort, vehicle safety, and related vehicle performance. Therefore, the thermal management system is a critical system in a vehicle.

[0003] Especially for electric vehicles, the thermal management system is more important and demanding. In general, the thermal management system of an electric vehicle needs to control the temperature of the battery (e.g., the power battery of the electric vehicle), the electric drive unit (e.g., the drive motor that utilizes the electric energy provided by the power battery to power the running of the electric vehicle), the on-board charger, the passenger compartment, etc. Specifically, at high temperatures, the heat of the battery, the electric drive unit, the on-board charging unit, the passenger compartment, etc. needs to be dissipated. At low temperatures, the thermal management system needs to heat the battery, the passenger compartment, etc.

[0004] Currently, thermal management systems for electric vehicles are expensive and bulky. Summary of the Invention

[0005] The embodiments of the present application provide a vehicle thermal management system, a drive unit, and an electric vehicle. The compressor and the heating resistor of the air conditioner can be driven by a single drive unit. This can reduce the cost of the thermal management system of the electric vehicle.

[0006] According to a first aspect, an embodiment of the present application provides a thermal management system for temperature control of an electric vehicle. The thermal management system includes: a motor, N resistor branches, and a driver configured to drive and operate resistors on the motor and the N resistor branches, where N is a positive integer greater than 1. The motor is configured to rotate under the action of an alternating current and drive and operate a compressor of an air conditioner. The driver includes a control circuit and an inverter circuit. Each of the N bridge arms of the inverter circuit is connected to one terminal of the motor, and different bridge arms are connected to different terminals. A midpoint of each of the N bridge arms is connected to one of the N resistor branches, and different bridge arms are connected to different resistor branches. A first switch is coupled between the midpoint of each bridge arm and the resistor branch connected to the bridge arm. The control circuit is configured to: control all the first switches corresponding to the N bridge arms to be in an open state, and control the inverter circuit to output an alternating current to the motor. The control circuit is configured to: control all first switches corresponding to the N bridge arms to a closed state, and control the inverter circuit to output currents to the N resistive branches.

[0007] In other words, the driver of the thermal management system provided in this embodiment can be configured to drive the compressor of the air conditioner and can be configured to drive the heating resistor. Therefore, it is not necessary to set one set of drivers separately for the compressor and the heating resistor. This reduces the cost of the thermal management system, saves the space of the thermal management system, and reduces the volume of the thermal management system.

[0008] In a possible implementation, the driver is configured to independently drive and operate the motor to drive the compressor if a difference obtained by subtracting the energy efficiency ratio of the resistor from the energy efficiency ratio of the compressor is greater than or equal to a first threshold.

[0009] That is, in this implementation, if the energy efficiency ratio of the compressor is greater than the energy efficiency ratio of the resistor, the driver may drive the compressor without operatively driving the resistor, reducing energy consumption.

[0010] In a possible implementation, the driver is configured to independently drive and operate the resistors on the resistor branch if a difference obtained by subtracting the energy efficiency ratio of the compressor from the energy efficiency ratio of the resistor is greater than or equal to a second threshold.

[0011] That is, if the energy efficiency ratio of the resistor is greater than the energy efficiency ratio of the compressor, the driver may drive the resistor for heating rather than driving the compressor for heating, reducing energy consumption.

[0012] In a possible implementation, the driver further includes a second switch disposed between the first resistive branch and the battery, the first resistive branch being one or more of the N resistive branches. The control circuit is configured to: control all the first switches corresponding to the N bridge arms to enter an open state, and control the second switches to enter a closed state, so that resistors on the first resistive branch can obtain current from the battery.

[0013] That is, in this implementation, by disposing the second switch, the battery can power one or more of the N resistor branches when all the first switches corresponding to the N bridge arms are in an open state, allowing the simultaneous operation of the compressor and resistors to be controlled by a single driver.

[0014] In a possible implementation, the second switch includes one or more switches, the one or more switches having a one-to-one correspondence with the one or more resistor branches.

[0015] That is, one second switch is arranged for each of one or more resistor branches, so that the amount of resistance operating simultaneously with the compressor can be adjusted.

[0016] In a possible implementation, the second switch is disposed between the first resistor and the negative terminal of the battery.

[0017] That is, the second switch can be used as a low-side driver of the first resistor, which can improve the security of the thermal management system and further reduce the cost of the thermal management system.

[0018] In a possible implementation, the driver is configured to drive the compressor and one or more resistors on one or more resistor branches to operate simultaneously if a difference between the energy efficiency ratio of the compressor and the energy efficiency ratio of the resistors is within a preset range.

[0019] That is, in this implementation, if the energy efficiency ratio of the compressor is approximately equal to the energy efficiency ratio of the resistor, then both the air conditioner and the resistor can be used for heating.

[0020] In a possible embodiment, the switch element on one side of the midpoint of the bridge arm is a third switch element coupled to a first electrode of the battery, and the switch element on the other side of the midpoint of the bridge arm is a fourth switch element coupled to a second electrode of the battery. The control circuit is configured to: control the third switch elements on the N bridge arms to be simultaneously opened and control the fourth switch elements on the N bridge arms to be simultaneously closed, such that the inverter circuit outputs current to the N resistive branches.

[0021] That is, in this implementation, in the inverter circuit, the switch elements on one side of each of the bridge arms are controlled to open simultaneously, and the switch elements on the other side of each of the bridge arms are controlled to close simultaneously, and the inverter circuit can be used as a power supply circuit for the resistor branch to output a current to the resistor branch.

[0022] In a possible implementation, the first electrode is a positive terminal of a battery and the second electrode is a negative terminal of the battery, or the first electrode is a negative terminal of the battery and the second electrode is a positive terminal of the battery.

[0023] That is, in this implementation, the lower bridge arm of the inverter circuit can be used as a low-side driver of the N resistor branches, and the upper bridge arm of the inverter circuit can be used as a high-side driver of the N resistor branches, thereby allowing for flexible control of the N resistor branches.

[0024] In a possible implementation, the control circuit is configured to control the time period during which the fourth switch elements on the N bridge arms are closed during a single pulse period to control the magnitude of the current output by the inverter circuit to the N resistors.

[0025] That is, in this implementation, the duty cycle of the fourth switch element is controlled to control the magnitude of the current output to the N resistor branches, so as to flexibly control the power of the N resistor branches.

[0026] In possible embodiments, the driver includes a relay, and the relay is used as the first switch corresponding to each of the N bridge arms; or the first switch corresponding to one or more of the N bridge arms is a circuit breaker; or the first switch corresponding to one or more of the N bridge arms is an insulated gate bipolar transistor IGBT or a metal oxide semiconductor field effect transistor MOSFET.

[0027] That is, in this implementation, the switch element between the inverter circuit and the heating resistor may include multiple options to allow flexibility in driver design.

[0028] In a possible implementation, the resistors of the N resistance branches are positive temperature coefficient PTC resistors.

[0029] The resistance value of PTC increases with increasing temperature, which has high security. In this implementation, PTC is used as a heating resistor, which can improve the security of the thermal management system.

[0030] According to a second aspect, an embodiment of the present application provides a drive device. The drive device includes a control circuit and an inverter circuit having N bridge arms, where N is a positive integer greater than 1. A midpoint of each of the N bridge arms is configured to be connected to one terminal of a motor, and different bridge arms of the N bridge arms are connected to different terminals. The motor is configured to drive and operate a compressor of an air conditioner when rotating, allowing the air conditioner to perform heating or cooling. A midpoint of each of the N bridge arms is configured to be connected to one of the N resistance branches, and different bridge arms in the N bridge arms are connected to different resistance branches. A first switch is coupled between the midpoint of each of the N bridge arms and the resistance branch connected to each bridge arm. One or more resistors are disposed in each of the N resistance branches, and the resistors are configured to convert electrical energy into thermal energy. The control circuit is configured to: control all first switches corresponding to the N bridge arms to be in an open state, and control the inverter circuit to output an alternating current to the motor. The control circuit is configured to: control all first switches corresponding to the N bridge arms to a closed state, and control the inverter circuit to output currents to the N resistive branches.

[0031] In a possible implementation, if a difference obtained by subtracting the energy efficiency ratio of the resistor from the energy efficiency ratio of the compressor is greater than or equal to a first threshold value, the control circuit is configured to: control all first switches corresponding to the N bridge arms to be in an open state, and control the inverter circuit to output an alternating current to the motor.

[0032] In a possible implementation, if a difference obtained by subtracting the energy efficiency ratio of the compressor from the energy efficiency ratio of the resistor is greater than or equal to a second threshold value, the control circuit is configured to: control all first switches corresponding to the N bridge arms to be in a closed state, and control the inverter circuit to output current to the N resistor branches.

[0033] In a possible implementation, the driving device further includes a second switch disposed between the first resistive branch and the battery, the first resistive branch being one or more of the N resistive branches. The control circuit is configured to: control all the first switches corresponding to the N bridge arms to enter an open state, and control the second switches to enter a closed state, so that resistors on the first resistive branch obtain current from the battery.

[0034] In a possible implementation, the second switch includes one or more switches, the one or more switches having a one-to-one correspondence with the one or more resistor branches.

[0035] In a possible implementation, the second switch is arranged between the first resistive branch and the negative terminal of the battery.

[0036] In a possible implementation, if a difference between the energy efficiency ratio of the compressor and the energy efficiency ratio of the resistor is within a preset range, the control circuit is configured to: control all first switches corresponding to the N bridge arms to enter an open state, and control the second switches to enter a closed state, so that the resistors on the first resistance branch draw current from the battery.

[0037] In a possible implementation, the switch element on one side of the midpoint of the bridge arm is a third switch element coupled to a first electrode of the battery, and the switch element on the other side of the midpoint of the bridge arm is a fourth switch element coupled to a second electrode of the battery. The control circuit is configured to: control the third switch elements on the N bridge arms to be simultaneously opened and control the fourth switch elements on the N bridge arms to be simultaneously closed, such that the inverter circuit outputs current to the N resistive branches.

[0038] In a possible implementation, the first electrode is a positive electrode of a battery and the second electrode is a negative electrode of the battery, or the first electrode is a negative electrode of the battery and the second electrode is a positive electrode of the battery.

[0039] In a possible implementation, the control circuit is configured to control the time period during which the fourth switch elements on the N bridge arms are closed during a single pulse period to control the magnitude of the current output by the inverter circuit to the N resistive branches.

[0040] In a possible implementation, the driving device includes a relay, and the relay is used as the first switch corresponding to each of the N bridge arms; or the first switch corresponding to one or more of the N bridge arms is a circuit breaker; or the first switch corresponding to one or more of the N bridge arms is an insulated gate bipolar transistor IGBT or a metal oxide semiconductor field effect transistor MOSFET.

[0041] It can be understood that the drive device provided in the second aspect can be configured to drive the compressor and the motor of the thermal management system provided in the first aspect. For beneficial effects of the drive device, please refer to the description of the beneficial effects of the thermal management system provided in the first aspect.

[0042] According to a third aspect, an embodiment of the present application provides an electric vehicle including the thermal management system provided in the first aspect or the drive unit provided in the second aspect.

[0043] According to the thermal management system and the drive provided in the embodiment of the present application, a single drive or driver can be used to drive the compressor and the heating resistor, which can reduce the use of electronic components and lines, reduce the cost of the thermal management system, and save the space of the thermal management system, allowing the thermal management system to be designed to have a small volume. Also, since no additional high-voltage and low-voltage separation is required, the cost of the thermal management system can be further reduced. [Brief description of the drawings]

[0044] [Figure 1] FIG. 2 is a schematic diagram showing the structure of a drive device for driving and operating a compressor.

[0045] [Diagram 2] 1 is a schematic diagram showing the structure of a drive device for driving and operating a PTC.

[0046] [Figure 3A] FIG. 1 is a schematic diagram illustrating a structure of a thermal management system according to an embodiment of the present application.

[0047] [Figure 3B] FIG. 1 is a schematic diagram illustrating a structure of a thermal management system according to an embodiment of the present application.

[0048] [Figure 3C] 3C is a schematic diagram of the structure of the resistive branch shown in FIG. 3A or FIG. 3B.

[0049] [Figure 3D] FIG. 3C is a schematic diagram of the structure of the resistive branch shown in FIG. 3A or FIG. 3B.

[0050] [Figure 4] FIG. 2 is a schematic diagram of the operating principle of the thermal management system in an independent operating mode of the compressor according to an embodiment of the present application.

[0051] [Figure 5A] FIG. 13 is a simulation diagram of the compressor motor input current in the compressor independent operating mode.

[0052] [Figure 5B] FIG. 13 is a simulation diagram of the input current of the heating resistor in the compressor independent operation mode.

[0053] [Figure 6] 2 is a schematic diagram of the working principle of the thermal management system in a mode in which the heating resistors operate independently according to an embodiment of the present application; FIG.

[0054] [Figure 7A] FIG. 13 is a simulation diagram of the input current of the compressor motor in the heating resistor independent operating mode.

[0055] [Figure 7B] FIG. 13 is a simulation diagram of the input current of each resistor of the heating resistor in a mode in which the heating resistors operate independently.

[0056] [Figure 8] FIG. 2 is a schematic diagram of the working principle of the thermal management system in a mode in which the compressor and the heating resistor work simultaneously according to an embodiment of the present application;

[0057] [Figure 9A] FIG. 13 is a simulation diagram of the input current of the compressor motor in a mode in which the compressor and the heating resistor operate simultaneously.

[0058] [Figure 9B] FIG. 11 is a simulation diagram of the input current of each resistor of the heating resistor in a mode in which the compressor and the heating resistor operate simultaneously.

[0059] [Figure 10] 1 is a schematic diagram of a structure of a thermal management system according to an embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060] Hereinafter, the technical solutions of the embodiments in this application will be described with reference to the accompanying drawings.

[0061] In general, the battery (e.g., power battery) of an electric vehicle needs to operate within an appropriate temperature range. If the battery temperature is too high, it may affect the battery's lifespan and may pose a security risk. If the battery temperature is too low, the available capacity of the battery may be significantly reduced, which limits the performance of the battery. Therefore, when the battery operates, the temperature of the battery needs to be maintained within a certain range. Also, unlike conventional fuel vehicles that may use engine coolant to heat the passenger compartment, electric vehicles need to use the electric energy of the battery to heat the passenger compartment and other components.

[0062] For these reasons, the thermal management systems of electric vehicles are more important and demanding than those of traditional fuel vehicles.

[0063] In general, the thermal management system of an electric vehicle includes water loops, cooling circuits, temperature and pressure sensors, water valves, solenoid valves, water pumps, air conditioner compressors, air conditioner boxes, positive temperature coefficient (PTC) resistors, etc. to heat or cool the battery and passenger compartment of the electric vehicle, and to cool the electric drive unit, on-board charger, etc.

[0064] In this embodiment of the application, the electric vehicle may be a pure electric vehicle (pure electric vehicle / battery electric vehicle, pure EV / battery EV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle (NEV), etc.

[0065] The compressor of an air conditioner is sometimes called a compressor for short. In general, it can be understood that the energy efficiency ratio of a compressor is high and can reach about 3:1. In other words, a compressor can transfer about 3kW of heat while consuming 1kW of power. However, at lower ambient temperatures, the energy efficiency ratio of a compressor decreases. For example, the energy efficiency ratio of a compressor using R134A refrigerant as a refrigerant is about 1:1 at an ambient temperature of about minus 7°C. As the ambient temperature decreases, the energy efficiency ratio of the compressor decreases further. At extremely low ambient temperatures, the refrigerant in the compressor may not be able to build up pressure. Specifically, the temperature of the compressor's condenser and reservoir is so low that there is not enough pressure to pump liquid refrigerant to the evaporator when the compressor is started.

[0066] The PTC is configured to heat water in a water loop, which can be used to heat other components. The resistance of the PTC increases with increasing temperature. This has high security. At extremely low ambient temperatures, the thermal management system may use the PTC to heat batteries, etc. At lower ambient temperatures, the compressor and PTC can be used simultaneously to heat batteries, etc. At high ambient temperatures, the compressor can be used independently to heat or cool batteries, etc.

[0067] It can be understood that extremely low, low, and high ambient temperatures each correspond to a different temperature range. For compressors using different refrigerants, the temperature range corresponding to extremely low ambient temperature may be different, the temperature range corresponding to low ambient temperature may also be different, and the temperature range corresponding to high ambient temperature may also be different. For example, for a compressor using R134A refrigerant as the refrigerant, an extremely low ambient temperature may be less than minus 15°C, a low ambient temperature may be between minus 15°C and minus 7°C, and a high ambient temperature may be above minus 7°C.

[0068] In the solution, the thermal management system uses two independent drives to control the compressor and the PTC. The drive to control the compressor is shown in Figure 1, and the drive to control the PTC is shown in Figure 2. In this solution, the compressor requires one drive and the PTC requires another drive. The thermal management system of the electric vehicle needs to provide space to accommodate the two drives. This motors a large volume of the thermal management system. Also, the power of the compressor and the power of the PTC are about 8 kilowatts, and they require high voltage power supplies. That is, each of the power circuits of the compressor drive and the power circuits of the PTC drive needs to use high voltage power harnesses and matching connectors, fuses, etc., which increases the circuit cost. Also, each of the compressor drive and the PTC drive needs high voltage and low voltage insulation between the power circuits and the control circuits. This also increases the cost of the thermal management system.

[0069] The embodiments of the present application provide a thermal management system, in which one driver can be used to operate a compressor and a heating resistor, so that the cost of the thermal management system can be reduced and the volume of the thermal management system can be reduced.

[0070] FIG. 3A shows an example of a thermal management system. In this example, the thermal management system may include a motor 300. The motor 300 may rotate under the driving of an alternating current to drive and operate a compressor of an air conditioner so that the air conditioner can perform cooling or heating. The motor 300 may have N terminals, where N is a positive integer greater than 1. The N terminals may receive an alternating current to drive and rotate the motor 300. For example, N may be 3, and the three terminals of the motor 300 are a U-phase terminal, a V-phase terminal, and a W-phase terminal, respectively.

[0071] The thermal management system may include a heating resistor 400. The heating resistor 400 may include N resistive branches, and the N resistive branches may be arranged in parallel. That is, different resistive branches of the N resistive branches are connected in parallel. When a power source is connected, the resistors of the N resistive branches may convert electrical energy into thermal energy and dissipate heat. For example, as shown in FIG. 3A, the N resistive branches may include resistive branch 410, resistive branch 420, and resistive branch 430. For example, as shown in FIG. 3B, the N resistive branches may include resistive branch 410, resistive branch 420, resistive branch 430, and resistive branch 440. Note that the heating resistor 400 shown in FIG. 3A and FIG. 3B is an example for describing the amount of resistive branches included in the thermal management system, and is not intended to impose limitations. The thermal management system may include further amounts of resistive branches, for example, five resistive branches or six resistive branches, which are not listed one by one in this specification.

[0072] In some embodiments, the resistors on the resistive branches of the N resistive branches may be PTCs.

[0073] In some embodiments, one resistor may be placed in one of the N resistor branches.

[0074] In some embodiments, multiple resistors may be arranged in one of the N resistor branches. For example, multiple resistors on the same resistor branch may be arranged in series. For example, as shown in FIG. 3C, resistor branch 410 may be composed of resistor 411 and resistor 412 connected in series. That is, circuit branch 410 includes resistor 411 and resistor 412 arranged in series. For example, multiple resistors may be arranged in parallel on the same resistor branch. For example, as shown in FIG. 3D, resistor branch 410 may be composed of resistor 411 and resistor 412 connected in parallel.

[0075] The thermal management system may include a driver 500 configured to control the rotation of the motor 300 and control the heating resistor 400 to release heat. The driver 500 may include an inverter circuit 510. The inverter circuit 510 may include 2N switch elements, and every two switches may be arranged in series to form a bridge arm or arms. The 2N switch elements may form N bridge arms. Different bridge arms in the inverter circuit 510 are arranged in parallel. One switch element on each bridge arm is coupled to the positive pole of the battery 600, and the other switch element on the bridge arm is coupled to the negative pole of the battery. In other words, in an electric circuit, one switch element on each bridge arm is closer to the positive pole of the battery 600, and the other switch element on the bridge arm is closer to the negative pole of the battery 600. The switch element coupled to the positive pole of the battery is the switch element on the positive pole side of the battery, or the switch element close to the positive pole of the battery in the electric circuit. The switch element coupled to the negative terminal of the battery is the switch element on the negative side of the battery or the switch element close to the negative terminal of the battery in the electric circuit. For a bridge arm, the switch element coupled to the positive terminal of the battery may be referred to as the upper bridge arm or the upper transistor of the bridge arm, and the switch element coupled to the negative terminal of the battery may be referred to as the lower bridge arm or the lower transistor of the bridge arm. The point between the two switch elements on each bridge arm may be referred to as the midpoint. That is, for a bridge arm, the midpoint is between the lower bridge arm and the upper bridge arm of the bridge arm.

[0076] In some embodiments, the switch elements included in the inverter circuit 510 may be elements made of semiconductor silicon, such as insulated gate bipolar transistors (IGBTs), metal-oxide-semiconductor field effect transistors (MOSFETs), etc. Other examples will not be listed one by one here.

[0077] In some embodiments, as shown in FIG. 3A, the inverter circuit 510 may include three bridge arms, that is, the inverter circuit 510 may be a three-phase bridge circuit. Specifically, the inverter circuit 510 may include a bridge arm 511, a bridge arm 512, and a bridge arm 513. The bridge arms are arranged in parallel. The bridge arm 511 includes a switch element 5111 and a switch element 5112. The switch element 5111 and the switch element 5112 are arranged in series, with the switch element 5111 being coupled to the positive pole of the battery 600 and the switch element 5112 being coupled to the negative pole of the battery 600. There is a midpoint 5113 between the switch element 5111 and the switch element 5112. The bridge arm 512 includes a switch element 5121 and a switch element 5122. The switch element 5121 and the switch element 5122 are arranged in series, with the switch element 5121 coupled to the positive terminal of the battery 600 and the switch element 5122 coupled to the negative terminal of the battery 600. There is a midpoint 5123 between the switch element 5121 and the switch element 5122. The bridge arm 513 includes a switch element 5131 and a switch element 5132. The switch element 5131 and the switch element 5132 are arranged in series, with the switch element 5131 coupled to the positive terminal of the battery 600 and the switch element 5132 coupled to the negative terminal of the battery 600. There is a midpoint 5133 between the switch element 5131 and the switch element 5132.

[0078] Next, a method of connection between the inverter circuit 510 and the motor 300 will be described.

[0079] See FIG. 3A. The midpoint of each bridge arm is connected to one of the N terminals of the motor 300. The midpoints of different bridge arms are connected to different terminals. That is, the bridge arms in the N bridge arms have a one-to-one correspondence with the terminals in the N terminals, and the midpoint of each bridge arm can be connected to the terminal corresponding to the bridge arm. For example, N is 3. As shown in FIG. 3A, the midpoint 5113 is connected to one terminal of the motor 300, the midpoint 5123 is connected to the other terminal of the motor 300, and the midpoint 5133 is connected to the remaining terminal of the motor 300.

[0080] Next, a method of connection between the inverter circuit 510 and the heating resistor 400 will be described.

[0081] See FIG. 3A. The midpoint of each bridge arm may be connected to one of the N resistor branches of the heating resistor 400. The midpoint of different bridge arms may be connected to different resistor branches. That is, the bridge arms in the N bridge arms correspond one-to-one with the resistor branches in the N resistor branches, and the midpoint of each bridge arm may be connected to the resistor branch corresponding to the bridge arm. For example, N is 3. As shown in FIG. 3A, the resistor branch 430 corresponds to the bridge arm 511, and the midpoint 5113 may be connected to the resistor branch 430. The resistor branch 420 corresponds to the bridge arm 512, and the midpoint 5123 may be connected to the resistor branch 420. The resistor branch 410 corresponds to the bridge arm 513, and the midpoint 5133 may be connected to the resistor branch 410. It can be understood that the midpoint of each bridge arm is connected to one end of the corresponding resistor branch, and the other end of the resistor branch is directly connected to the battery 600. One end of the resistor branch connected to the midpoint of the bridge arm may be called the D1 end, and the one end directly connected to the battery may be called the D2 end. For example, the D2 terminal may be the positive terminal of the resistive branch, i.e., the resistive branch is directly connected to the positive pole of the battery 600. The D1 terminal may be the negative terminal of the resistive branch, i.e., the resistive branch is indirectly connected to the negative pole of the battery 600 through the midpoint of the bridge arm. Thus, the associated switch element in the inverter circuit 510 may be used as a low-side driver to control the current output from the battery 600 to the resistive branch. For example, the D1 terminal of the resistor may be the negative terminal of the resistive branch, and the D2 terminal of the resistor may be the positive terminal of the resistive branch. Thus, the associated switch element in the inverter circuit 510 may be used as a high-side driver to control the current output from the battery 600 to the resistive branch.

[0082] Each bridge arm of the inverter circuit 510 may further correspond to one switch element S (not shown). Each switch element S may be disposed on a connection line between a midpoint of the corresponding bridge arm and a resistor branch corresponding to the bridge arm. When the switch element S is closed, the midpoint of the bridge arm corresponding to the switch element S is connected to the resistor branch corresponding to the bridge arm. When the switch element S is opened, the midpoint of the bridge arm corresponding to the switch element S is disconnected from the resistor branch corresponding to the bridge arm. For example, the switch element S corresponding to each bridge arm of the inverter circuit 510 is relay 520. In other words, the relay 520 may be disposed between the inverter circuit 510 and the heating resistor 400, and may be configured to control the connection or disconnection between the midpoint of each bridge arm of the inverter circuit 510 and the corresponding resistive branch of the heating resistor 400. In other words, the relay 520 may be used as a switch element S corresponding to each of the N bridge arms of the inverter circuit 510, or in other words, the switch elements S corresponding to the N bridge arms may be integrated into the relay 520.

[0083] In some embodiments, as shown in FIG. 3A, one or more D1 terminals of one or more resistor branches (e.g., resistor branch 430) of the heating resistor 400 may further be directly connected to the battery 600, and a switch element 540 is disposed on the connection line between the D1 terminal and the battery 600. The electrodes of the battery 600 connected to one or more D1 terminals of the one or more resistor branches are different from the electrodes of the battery 600 connected to one or more D2 terminals of the one or more resistor branches. When one or more D2 terminals of the one or more resistor branches are connected to the positive pole of the battery 600, one or more D1 terminals of the one or more resistor branches are connected to the negative pole of the battery 600. When one or more D2 terminals of the one or more resistor branches are connected to the negative pole of the battery 600, one or more D1 terminals of the one or more resistor branches are connected to the positive pole of the current 600.

[0084] Continuing to refer to FIG. 3A . The driver 500 may further include a control circuit 530. The control circuit 530 may control the open or closed state of each switch element in the driver 500. The switch elements in the driver 500 may include a switch element in the inverter circuit 510, a switch element S between the inverter circuit 510 and the heating resistor 400, and a switch element 540. Thus, the control circuit 530 may control the current output from the battery 600 to the motor 300 and control the current output from the battery 600 to the heating resistor 400. Controlling the open or closed state of the switch element means, in particular, controlling the switch element to be opened or closed to disconnect or connect an electric circuit in which the switch element is arranged.

[0085] 3A, the control circuit 530 may include a drive circuit 531 and a decision circuit 532. The decision circuit 532 may generate a control command and send the control command to the drive circuit 531. The drive circuit 531 may control the open or closed state of each switch element in the driver 500 based on the control command. For example, the control command may be a low-voltage (e.g., 5V) logic signal. The drive circuit 531 may amplify the low-voltage logic signal to a high-voltage (e.g., 15V) signal that can drive the switch elements to open or close.

[0086] The above describes an example of the structure of the thermal management system in this embodiment. The thermal management system can be in a mode where the compressor operates independently, i.e., the motor 300 is independently controlled by the driver 500. Alternatively, the thermal management system can be in a mode where the thermal resistor operates independently, i.e., the heating resistor 400 is independently controlled by the driver 500.

[0087] Examples of the various control modes mentioned above will now be described with reference to the accompanying drawings.

[0088] See FIG. 4. The thermal management system may be in a mode in which the compressor operates independently. As mentioned above, the energy efficiency ratio of the compressor is affected by the ambient temperature of the compressor. When the ambient temperature of the compressor is high, the energy efficiency ratio of the compressor may be greater than 1 (i.e., 1:1), for example, reaching about 3 (i.e., 3:1). The heating principle of the resistor can be understood to be converting electrical energy into thermal energy. Under ideal conditions, the energy efficiency ratio of the resistor may be 1. However, in practical applications, limited by line losses, etc., the energy efficiency ratio of the resistor is usually about 0.9. The energy efficiency ratio of the resistor may be set to a fixed value, for example 0.9. In this embodiment of the present application, when the energy efficiency ratio of the compressor is greater than the energy efficiency ratio of the resistor, the thermal management system may use the mode in which the compressor operates independently to reduce energy consumption.

[0089] In some embodiments, the control circuit 530 may determine whether a difference obtained by subtracting the energy efficiency ratio of the resistor from the energy efficiency ratio of the compressor is equal to or greater than a threshold Y1. If the difference is equal to or greater than the threshold Y1, the thermal management system may be controlled to enter a mode in which the compressor operates independently. The threshold Y1 may be, for example, 0.1 or 0.2. Other examples are not listed one by one here. For example, the energy efficiency ratio of the compressor may be determined by the ambient temperature of the compressor. For example, a one-to-one correspondence between the temperature at a plurality of temperatures and the energy efficiency ratio at a plurality of energy efficiency ratios may be set. The control circuit 530 may obtain a current ambient temperature of the compressor, and then determine a current energy efficiency ratio of the compressor based on the ambient temperature and the correspondence, and may further determine whether a difference obtained by subtracting the energy efficiency ratio of the resistor from the current energy efficiency ratio of the compressor is equal to or greater than a threshold Y1. If the difference is equal to or greater than the threshold Y1, the thermal management system may be controlled to enter a mode in which the compressor operates independently. For example, it can be understood that a compressor may have different energy efficiency ratios at the same ambient temperature for different refrigerants. The energy efficiency ratio of the compressor may be determined based on the refrigerant of the compressor and the ambient temperature of the compressor. For example, energy efficiency ratios corresponding to each of a plurality of refrigerants at a plurality of different temperatures may be set or recorded. When the refrigerant currently used by the compressor and the current ambient temperature are obtained, the current energy efficiency ratio of the compressor may be determined. Also, it may be determined whether the difference between the current energy efficiency ratio of the compressor minus the energy efficiency ratio of the resistor is equal to or greater than a threshold Y1. If the difference is equal to or greater than the threshold Y1, the thermal management system may be controlled to enter a mode in which the compressor operates independently.

[0090] The above-mentioned ambient temperature of the compressor refers to the temperature of the environment in which the compressor is located. For example, a temperature sensor may be installed near the compressor. The temperature sensor may transmit the collected temperature to the control circuit 530 in real time, or may transmit the recently collected temperature to the control circuit 530 at time intervals T. For example, the ambient temperature of the compressor may be the outside ambient temperature of the vehicle in which the compressor is located. In this example, the outside ambient temperature sensor of the vehicle may transmit the collected temperature to the control circuit 530 in real time, or may transmit the recently collected temperature to the control circuit 530 at time intervals T.

[0091] In a mode in which the compressor operates independently, the control circuit 530 may control the switch element S between the inverter circuit 510 and the heating resistor 400 to open and the switch element 540 to open. For example, as shown in FIG. 4, controlling the switch element S between the inverter circuit 510 and the heating resistor 400 to open may specifically mean controlling the relay 520 to open. Then, the control circuit 530 may control the opening and closing of each switch element of the inverter circuit 510 to convert the direct current output by the battery 600 into an alternating current and drive the motor 300 to rotate. The structure of the inverter circuit 510 shown in FIG. 4 is used as an example. When the switch element 5111 and the switch element 5112 are closed and another switch element of the inverter circuit 510 is open, the direction of the current output by the inverter circuit 510 to the motor 300 is the direction F1. When the switch elements 5121 and 5112 are closed and another switch element of the inverter circuit 510 is open, the direction of the current output by the inverter circuit 510 to the motor 300 is direction F2. Based on the structure of the inverter circuit 510 shown in FIG. 4 and the way in which the inverter circuit 510 is connected to the motor 300, the direction F2 is opposite to the direction F1. This can generate an AC current. Note that the above description is merely an example of the process in which the inverter circuit 510 converts a DC current to an AC current, and is not intended to be limiting. Different switch elements in the inverter circuit 510 can be opened and closed under the control of the control circuit 530 to generate other forms of AC current or more complex AC current. For more details, please refer to the description of the inverter circuit in the prior art. Here, the details of each one will not be described in detail.

[0092] In some embodiments, the control circuit 530 may control the magnitude of the current that the inverter circuit 510 outputs to the motor 300 in order to control the power of the motor 300 by controlling the duty cycle of the inverter circuit 510. The duty cycle refers to the ratio of the power-on period in the pulse period to the total period of the pulse period. The pulse period refers to the period from the start of one power-on to the start of the next power-on in the case of intermittent or periodic power-on. The current magnitude of the alternating current may be the average current value in the pulse period. Thus, the magnitude of the alternating current may be controlled by controlling the value of the duty cycle. For example, when the circuit is powered on, the current magnitude of the current that the circuit outputs may be set to 100A. The duty cycle of the circuit may also be set to 25%, i.e., in the pulse period, the circuit is powered on for 25% of the period and not powered on for the remaining 75% of the period. In this case, the current magnitude that the circuit outputs in the pulse period is 25A. In this manner, by controlling the duty cycle of the inverter circuit 510, an AC current of any magnitude can be output to the motor 300.

[0093] In a specific example, the control circuit 530 can control the inverter circuit 510 to output the AC current shown in FIG. 5A to the motor 300, where the current amplitude is 19A. The AC current shown in FIG. 5A is only an example for illustration. In this embodiment of the present application, the control circuit 530 can control the inverter circuit 510 to input any expected current to the motor 300. For the method of controlling the magnitude of the current, please refer to the above description. The details will not be described again here.

[0094] Also, as described above, in the compressor independent operating mode, relay 520 and switch element 540 are open. Therefore, each resistor of heating resistor 400 is not powered on, that is, battery 600 does not input current to each resistor of heating resistor 400. As specifically shown in FIG. 5B, the current of each resistor of heating resistor 400 is zero.

[0095] See FIG. 6. The thermal management system may be in the mode in which the heating resistor operates independently. When the compressor's ambient temperature is low, the compressor's energy efficiency ratio may be less than 1:1 or lower than the resistor's energy efficiency ratio. Please refer to the above description for how to obtain the compressor's energy efficiency ratio and the resistor's energy efficiency ratio. Details will not be described again here. In this embodiment of the present application, when the compressor's energy efficiency ratio is lower than the resistor's energy efficiency ratio, the thermal management system may use the mode in which the heating resistor operates independently to reduce energy consumption.

[0096] In some embodiments, the control circuit 530 may determine whether the difference obtained by subtracting the energy efficiency ratio of the compressor from the energy efficiency ratio of the resistor is equal to or greater than a threshold Y2. If the difference is equal to or greater than the threshold Y2, the thermal management system may be controlled to enter a mode in which the heating resistor operates independently. The threshold Y2 may be preset, for example, 0.1 or 0.2. Other examples are not listed here one by one.

[0097] In a mode in which the heating resistor operates independently, the control circuit 530 controls the switch element S between the inverter circuit 510 and the heating resistor 400 to be closed, controls all upper bridge arms (or lower bridge arms) in the inverter circuit 510 to be simultaneously opened, and controls all lower bridge arms (or upper bridge arms) in the inverter circuit 510 to be simultaneously closed to allow the battery 600 to be connected to the heating resistor 400, thereby outputting a current to the heating resistor 400, so that the heating resistor heats up.

[0098] The method of operation of the driver 500 in the independently operating heater resistor mode will now be specifically described.

[0099] In some embodiments, the inverter circuit 510 may be used as a low-side driver of the heating resistor 400 to allow the heating resistor 400 to be connected to the battery 600. Specifically, when the thermal management system is in a mode in which the heating resistor operates independently, all upper bridge arms of the inverter circuit 510 are open, and the switch element S between the inverter circuit 510 and the heating resistor 400 is closed. Since all lower bridge arms of the inverter circuit 510 are closed simultaneously, the voltage difference between different terminals of the motor 300 is zero, and no current input is generated. The simultaneous closure of all lower bridge arms of the inverter circuit 510 allows the resistor of the heating resistor 400 to be connected to the battery 600, obtaining electrical energy from the battery 600 and generating heat.

[0100] In an illustrative example of these embodiments, the control circuit 530 may control the duty cycle of the lower bridge arms of the inverter circuit 510 to control the magnitude of the current input to the heating resistor 400. For details of the duty cycle, please refer to the above description. Details will not be described again here. Note that when controlling the duty cycle of the lower bridge arms of the inverter circuit 510, the control circuit 530 needs to control all the lower bridge arms of the inverter circuit 510 to be simultaneously closed, then control all the lower bridge arms of the inverter circuit 510 to be simultaneously opened, then control all the lower bridge arms of the inverter circuit 510 to be simultaneously closed, and so on. In this way, the voltage difference between different terminals of the motor 300 is always 0 while the current input to the heating resistor 400 is controlled.

[0101] In an illustrative example of this embodiment, an example of a case where the inverter circuit 510 can be used as a low-side driver of the heat resistor 400 will be described with reference to Fig. 6. During a period in which the thermal management system is in a mode in which the heat resistor operates independently, the switch elements 5111, 5121, and 5131 are all open, and the relay 520 is closed. The switch elements 5112, 5122, and 5132 are closed simultaneously, or alternately closed and opened simultaneously, so that the heat resistor 400 can obtain electric energy from the battery 600 and further generate heat.

[0102] In some embodiments, the inverter circuit 510 can be used as a high-side driver of the heating resistor 400 to connect the heating resistor 400 to the battery 600. Specifically, when the thermal management system is in a mode in which the heating resistors operate independently, all the lower bridge arms in the inverter circuit 510 are in an open state, and the switch element S between the inverter circuit 510 and the heating resistor 400 is in a closed state. Since all the upper bridge arms in the inverter circuit 510 are closed simultaneously, the voltage difference between different terminals of the motor 300 is zero, and no current input occurs. Closing all the upper bridge arms in the inverter circuit 510 simultaneously allows the resistors of the heating resistor 400 to be connected to the battery 600, obtaining electrical energy from the battery 600 and further generating heat.

[0103] In an illustrative example of these embodiments, the control circuit 530 can control the duty cycle of the upper bridge arms of the inverter circuit 510 to control the magnitude of the current input to the heating resistor 400. For details on the duty cycle, please refer to the above description. Details will not be described again here. Note that when controlling the duty cycle of the upper bridge arms of the inverter circuit 510, the control circuit 530 needs to control all the upper bridge arms of the inverter circuit 510 to be simultaneously closed, then control all the upper bridge arms of the inverter circuit 510 to be simultaneously opened, then control all the upper bridge arms of the inverter circuit 510 to be simultaneously closed, and so on. In this way, the voltage difference between the different terminals of the motor 300 is always zero while controlling the current input to the heating resistor 400.

[0104] In a specific example, as shown in Figure 7A, the input current of the motor 300 can be 0. Specifically, as shown in Figure 7B, the input current of each resistor of the heating resistor 400 is not 0.

[0105] According to the above-mentioned solution, the thermal management system can use a single driver to drive and operate the compressor and the heating resistor, thereby saving space in the thermal management system and reducing the cost of the thermal management system.

[0106] In some embodiments, when one or more D1 terminals of one or more resistive branches (e.g., resistive branch 430) in heating resistor 400 are directly connected to battery 600 and switch element 540 is disposed on the connection line between the D1 terminal and battery 600 (see the above description of the embodiment shown in FIG. 3A for details), the thermal management system may alternatively be in a mode in which the compressor and heating resistor operate simultaneously, i.e., driver 500 controls motor 300 and heating resistor 400 to operate simultaneously.

[0107] When the difference between the energy efficiency ratio of the compressor and the energy efficiency ratio of the resistor is small, the thermal management system may use the mode in which the compressor and the heating resistor work simultaneously. Specifically, the range or interval may be preset, such as the interval (-0.1, 0.1) or the interval (-0.2, 0.2). Other examples are not listed here one by one. When the difference between the energy efficiency ratio of the compressor and the energy efficiency ratio of the resistor falls within the above preset interval, the thermal management system may enter the mode in which the compressor and the heating resistor work simultaneously.

[0108] See Figure 8. When the thermal management system is in a mode in which the compressor and the heating resistor are operating simultaneously, the switch element S or relay 520 between the inverter circuit 510 and the heating resistor 400 is in a closed state.

[0109] Therefore, the control circuit 530 can control the opening and closing of each switch element of the inverter circuit 510 to convert the DC current output of the battery 600 into AC current in order to drive and rotate the motor 300. For details, please refer to the description of the embodiment shown in FIG. 4 above. Details will not be described again here. In a specific example, in a mode in which the compressor and the heating resistor operate simultaneously, the input current of the motor 300 can be shown in FIG. 9A.

[0110] The control circuit 530 may also control the switch element 540 to close so that one or more resistive branches are connected to the battery 600 to obtain electrical energy and generate heat. For example, the control circuit 530 may further adjust the duty cycle of the switch element 540 to adjust the magnitude of the input current of one or more resistive branches.

[0111] It may be understood that when the compressor and the heating resistor operate simultaneously, the air conditioner can perform heating so that the compressor operates. Therefore, it is not necessary for the heating resistor 400 to operate at full load, in other words, it is not necessary for all of the N resistance branches of the heating resistor 400 to operate. Therefore, the one or more resistance branches can be some of the N resistance branches. For example, the one or more resistance branches can be specifically one resistance branch. Therefore, only one switch element 540 may be arranged to realize the driving of the resistance branch. In this way, the electronic components of the thermal management system are further saved, and the cost of the thermal management system is further reduced. As a specific example, as shown in FIG. 8, the one or more resistance branches can be the resistance branch 430, and the switch element 540 is a switch element corresponding to the resistance branch 430.

[0112] Note that the above description of the specific number of the one or more resistor branches and the specific number of the switch elements 540 is merely an example and is not intended to be limiting. In some other embodiments, the one or more resistor branches may be specifically two or more resistor branches. Correspondingly, the switch element 540 may be disposed between the D1 terminal of each of the two or more resistor branches and the battery 600, and each of the two or more resistor branches may be driven separately. In some other embodiments, the one or more resistor branches may be specifically two or more resistor branches. One switch element 540 may be disposed between the D1 terminal of each of the two or more resistor branches and the battery 600. That is, two or more resistor branches may be driven simultaneously using one switch element 540.

[0113] As a specific example, one or more resistor branches may be set as resistor branch 430. The input currents of resistor branch 430 and other resistor branches may be shown in Fig. 9B. Specifically, when switch element 540 is closed, resistor branch 430 may obtain an input current as shown in Fig. 9B, and the input currents of other resistor branches are zero.

[0114] Also, when a relay is used as the switch element S corresponding to the N bridge arms, when the relay needs to be closed in order to extend the life of the relay, the thermal management system may first enter a shutdown state and maintain the shutdown state for a certain period T1. In one example, the period T1 may be specifically about 500 ms, for example, 500 ms, 550 ms, or 450 ms. Other examples are not listed one by one in this specification. That is, before the relay is closed, the thermal management system is shut down for about 500 ms, and then the relay is closed. Next, a specific discussion will be made based on a scenario.

[0115] When the ambient temperature gradually decreases, the thermal management system may switch from a mode in which the compressor and the heating resistor operate simultaneously to a mode in which the heating resistor operates independently. From the above description, it can be seen that in the mode in which the heating resistor operates independently, the relay needs to be closed, so the inverter circuit 510 is used as the driving circuit for the heating resistor 400. Thus, the thermal management system may first enter a shutdown state, so that the compressor and the heating resistor 400 completely stop operating for a period T1. After that, the relay is closed and the thermal management system enters the mode in which the heating resistor operates independently.

[0116] If the ambient temperature drops suddenly, the thermal management system may switch from a mode in which the compressor operates independently to a mode in which the heating resistor operates independently. Thus, the thermal management system may first enter a shutdown state, so that the compressor stops operating completely for a period T1. Then, the relay is closed, so that the thermal management system enters a mode in which the heating resistor operates independently.

[0117] Through the above method, the operating load of the relay can be reduced, the life of the relay can be greatly improved, and the requirements of vehicle regulations can be met. In addition, the thermal management system is a large time inertia system, and the shutdown state occupies about 500ms, which does not have a significant impact on the heating of the vehicle.

[0118] In conclusion, the thermal management system provided in the embodiment of the present application can use a single driver to control the compressor and the heating resistor to operate. This reduces the use of electronic components and lines, reduces the cost of the thermal management system, and saves space in the thermal management system, so the thermal management system can be designed to have a smaller volume. Also, no additional high-voltage and low-voltage separation is required, which further reduces the cost of the thermal management system. Specifically, as shown in FIG. 10, a single electronic control unit (ECU) can be used to control the independent and coordinated operations of the compressor and the PTC. The ECU can be used as the driver 500.

[0119] It should be noted that the above embodiments are merely intended to illustrate the technical solutions of the present application, but are not intended to limit the present application. Although the present application has been described in detail with reference to the above embodiments, it should be understood that those skilled in the art may make modifications to the technical solutions described in the above embodiments or make equivalent substitutions to some technical features thereof without departing from the scope of the technical solutions of the embodiments of the present application.

Claims

1. 1. A thermal management system for controlling temperature in an electric vehicle, comprising: a motor configured to drive and operate a compressor of the air conditioner when rotating to enable the air conditioner to perform heating or cooling; N resistive branches arranged in parallel, with one or more resistors arranged in each resistive branch, the resistors configured to convert electrical energy into thermal energy, where N is a positive integer greater than 1; and A driver including a control circuit and an inverter circuit having N bridge arms; A midpoint of each of the N bridge arms is connected to one terminal of the motor, and different bridge arms of the N bridge arms are connected to different terminals; the midpoint of each of the N bridge arms is connected to one of the N resistive branches, different bridge arms within the N bridge arms are connected to different resistive branches, and a first switch is coupled between the midpoint of each of the N bridge arms and the resistive branch connected to each bridge arm; The control circuit is configured to: control all first switches corresponding to the N bridge arms to be in an open state, and control the inverter circuit to output an AC current to the motor; The control circuit is further configured to: control all the first switches corresponding to the N bridge arms to a closed state, and control the inverter circuit to output current to the N resistive branches; When a difference obtained by subtracting the energy efficiency ratio of the resistor from the energy efficiency ratio of the compressor is equal to or greater than a first threshold value, the control circuit is configured to: control all the first switches corresponding to the N bridge arms to be in the open state, and control the inverter circuit to output an AC current to the motor. Thermal management system.

2. When a difference between the energy efficiency ratio of the resistor minus the energy efficiency ratio of the compressor is greater than or equal to a second threshold, the control circuit is configured to: control all the first switches corresponding to the N bridge arms to the closed state and control the inverter circuit to output the current to the N resistor branches. The thermal management system of claim 1 .

3. The driver further includes a second switch disposed between a first resistor branch and a battery, the first resistor branch being one or more of the N resistor branches; The control circuit is configured to: control all the first switches corresponding to the N bridge arms to be in the open state and control the second switches to be in the closed state, so that resistors on the first resistance branch draw current from the battery; The thermal management system according to claim 1 or 2.

4. the second switch includes one or more switches, the one or more switches corresponding one-to-one to the one or more resistor branches; The thermal management system of claim 3.

5. the second switch is disposed between the first resistor branch and the negative terminal of the battery; 5. The thermal management system of claim 3 or 4.

6. When a difference between the energy efficiency ratio of the compressor and the energy efficiency ratio of the resistor falls within a preset range, the control circuit is configured to: control all the first switches corresponding to the N bridge arms to the open state and control the second switches to the closed state, such that the resistors on the first resistance branch draw the current from the battery. A thermal management system according to claim 3 which recites claim 2, or claim 4 which recites claim 3 which recites claim 2, or claim 5 which recites claim 3 or 4 which recites claim 2.

7. a switch element on one side of the midpoint of the bridge arm is a third switch element coupled to a first electrode of the battery, and a switch element on the other side of the midpoint of the bridge arm is a fourth switch element coupled to a second electrode of the battery; The control circuit is configured to: control third switch elements on the N bridge arms to be simultaneously opened and control fourth switch elements on the N bridge arms to be simultaneously closed, such that the inverter circuit outputs the current to the N resistor branches. A thermal management system according to any one of claims 3 to 6.

8. the first electrode is the positive electrode of the battery and the second electrode is the negative electrode of the battery; or the first electrode is the negative electrode of the battery and the second electrode is the positive electrode of the battery. The thermal management system of claim 7.

9. The control circuit is configured to control a period during which the fourth switch elements on the N bridge arms are in the closed state during a single pulse period to control a magnitude of the current output by the inverter circuit to the N resistor branches.

9. A thermal management system according to claim 7 or 8.

10. The driver includes a relay, and the relay is used as the first switch corresponding to each of the N bridge arms; or The first switch corresponding to one or more of the N bridge arms is a circuit breaker; or The first switches corresponding to one or more of the N bridge arms are insulated gate bipolar transistors IGBT or metal oxide semiconductor field effect transistors MOSFET. A thermal management system according to any preceding claim.

11. The resistor is a positive temperature coefficient PTC resistor. A thermal management system according to any preceding claim.

12. A driving device, the driving device comprising: a control circuit; and an inverter circuit having N bridge arms, where N is a positive integer greater than 1; A midpoint of each of the N bridge arms is configured to be connected to one terminal of a motor, and different bridge arms of the N bridge arms are connected to different terminals, and the motor is configured to drive and operate a compressor of the air conditioner when rotating, so as to enable the air conditioner to perform heating or cooling; the midpoint of each of the N bridge arms is connected to one of N resistive branches, different bridge arms of the N bridge arms are connected to different resistive branches, a first switch is coupled between the midpoint of each of the N bridge arms and the resistive branch connected to each bridge arm, one or more resistors are disposed in each of the N resistive branches, the resistors are configured to convert electrical energy into thermal energy; The control circuit is configured to: control all first switches corresponding to the N bridge arms to be in an open state, and control the inverter circuit to output an AC current to the motor; The control circuit is configured to: control all the first switches corresponding to the N bridge arms to a closed state, and control the inverter circuit to output a current to the N resistor branches; When a difference obtained by subtracting the energy efficiency ratio of the resistor from the energy efficiency ratio of the compressor is equal to or greater than a first threshold value, the control circuit is configured to: control all the first switches corresponding to the N bridge arms to be in the open state, and control the inverter circuit to output the AC current to the motor. Drive unit.

13. When a difference obtained by subtracting the energy efficiency ratio of the compressor from the energy efficiency ratio of the resistor is equal to or greater than a second threshold value, the control circuit is configured to: control all the first switches corresponding to the N bridge arms to be in the closed state and control the inverter circuit to output the current to the N resistor branches.

13. The drive arrangement according to claim 12.

14. The driving device further includes a second switch disposed between a first resistive branch and a battery, the first resistive branch being one or more of the N or more resistive branches; The control circuit is configured to: control all the first switches corresponding to the N bridge arms to be in the open state and control the second switches to be in the closed state, so that resistors on the first resistance branch draw current from the battery; 14. A drive arrangement according to claim 12 or 13.

15. the second switch includes one or more switches, the one or more switches corresponding one-to-one to the one or more resistor branches; 15. The drive arrangement according to claim 14.

16. the second switch is disposed between the first resistor branch and the negative terminal of the battery; 16. A drive arrangement according to claim 14 or 15.

17. When a difference between the energy efficiency ratio of the compressor and the energy efficiency ratio of the resistor falls within a preset range, the control circuit is configured to: control all the first switches corresponding to the N bridge arms to the open state and control the second switches to the closed state, such that the resistors on the first resistance branch draw the current from the battery. The drive device according to any one of claims 14 relying on claim 12, claim 15 relying on claim 14 relying on claim 12, or claim 16 relying on claim 14 or claim 15 relying on claim 12.

18. a switch element on one side of the midpoint of the bridge arm is a third switch element coupled to a first electrode of the battery, and a switch element on the other side of the midpoint of the bridge arm is a fourth switch element coupled to a second electrode of the battery; The control circuit is configured to: control third switch elements on the N bridge arms to be simultaneously opened and control fourth switch elements on the N bridge arms to be simultaneously closed, such that the inverter circuit outputs the current to the N resistor branches.

18. A drive arrangement according to any one of claims 14 to 17.

19. the first electrode is the positive electrode of the battery and the second electrode is the negative electrode of the battery; or the first electrode is the negative electrode of the battery and the second electrode is the positive electrode of the battery.

20. The drive arrangement of claim 18.

20. The control circuit is configured to control a period during which the fourth switch elements on the N bridge arms are in the closed state during a single pulse period to control a magnitude of the current output by the inverter circuit to the N resistor branches.

20. A drive arrangement according to claim 18 or 19.

21. The driving device includes a relay, and the relay is used as the first switch corresponding to each of the N bridge arms; or The first switch corresponding to one or more of the N bridge arms is a circuit breaker; or The first switches corresponding to one or more of the N bridge arms are insulated gate bipolar transistors IGBT or metal oxide semiconductor field effect transistors MOSFET.

21. A drive arrangement according to any one of claims 12 to 20.

22. 22. An electric vehicle comprising a thermal management system according to any one of claims 1 to 11 or a drive arrangement according to any one of claims 12 to 21.

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