Driving system having dual-motor architecture, and thermal management control method and vehicle

Abstract

A driving system having a dual-motor architecture, and a thermal management control method and a vehicle. In the system, a first end of a first inverter circuit (111) is electrically connected to a positive electrode output end of a power battery (100) by means of a second switch (160), a third end of the first inverter circuit (111) is electrically connected to the positive electrode output end of the power battery (100) by means of a first switch (150), and a first end of a second inverter circuit (131) is configured to be electrically connected to the positive electrode output end of the power battery (100) by means of the second switch (160). On the basis of the actual operating conditions of a whole vehicle, the first switch (150) and the second switch (160) are controlled to turn on or off, so as to execute a single-motor drive operating mode or a dual-motor drive operating mode.

Description

Drive system of dual-motor architecture, thermal management control method and vehicle

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410459043.X, filed on April 16, 2024, entitled “Drive system of dual-motor architecture, thermal management control method and vehicle”, Chinese Patent Application No. 202420791968.X, filed on April 16, 2024, entitled “Drive system of dual-motor architecture and vehicle”, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0003] The present application relates to the field of automobile driving technology, in particular to a drive system of dual-motor architecture, a thermal management control method and a vehicle. BACKGROUND

[0004] With the requirements of energy saving and emission reduction and the rise of fuel prices, major manufacturers are currently focusing on the layout of pure electric vehicles. As the core component of pure electric vehicles, the electric drive assembly is developing towards integration, lightweight, high power density and large torsional ratio. In addition to passenger cars, commercial vehicle electric drive axle technology has also developed rapidly. Currently, the electric drive assembly of commercial heavy trucks mainly adopts a single motor matched with a four-speed or six-speed AMT (Automated Mechanical Transmission). The system has low integration level, large volume and weight. At the same time, there is power interruption during AMT shifting, which results in poor driving experience. In some special vehicles (such as mine trucks), the application has the shortcomings of insufficient safety, etc. Due to the complexity of the actual use conditions of the whole vehicle, the single motor may work in the low efficiency area for a long time, resulting in high energy consumption of the whole vehicle. In addition, some manufacturers are currently exploring integrated dual-motor electric drive axles, but the reduction ratio is small or a planetary reduction mechanism is added to the wheel rim. This structure has poor heat dissipation, especially in the escape condition, which is easy to cause damage to the wheel rim planetary mechanism. SUMMARY

[0005] The main purpose of the embodiments of the present application is to provide a drive system of dual-motor architecture, a thermal management control method and a vehicle. By setting a first switch and a second switch, the single-motor driving mode or the dual-motor driving mode can be executed by controlling the switching of the first switch and the second switch according to the actual working conditions of the whole vehicle, so that the high efficiency area of the motor can be more fully utilized by the whole vehicle power system, the energy consumption of the whole vehicle is further reduced, the cost is reduced, the power performance and economy of the system are optimized, and the system has high integration level, compact volume and low cost.

[0006] To achieve the above object, a first aspect of the embodiment of the application provides a driving system of a dual-motor architecture, the system comprising: a power battery, a first motor controller, a first motor, a second motor controller, a second motor, a first switch, a second switch, a control module, a clutch and a reducer;

[0007] The first motor controller comprises a first inverter circuit, a first end of the first inverter circuit being electrically connected to a positive output end of the power battery through the second switch, a second end of the first inverter circuit being electrically connected to a negative output end of the power battery, a third end of the first inverter circuit being electrically connected to the positive output end of the power battery through the first switch, and each phase output end of the first inverter circuit being electrically connected to a winding of the first motor;

[0008] The second motor controller comprises a second inverter circuit, a first end of the second inverter circuit being electrically connected to the positive output end of the power battery through the second switch, a second end of the second inverter circuit being electrically connected to the negative output end of the power battery, the second end of the second inverter circuit also being electrically connected to the second end of the first inverter circuit, and each phase output end of the second inverter circuit being electrically connected to a winding of the second motor;

[0009] The first motor is connected to the clutch, the clutch is connected to the reducer, the second motor is connected to the reducer, and the reducer is used to be connected to a wheel end of a vehicle;

[0010] The control module is electrically connected to the first switch and the second switch, and is used to input control signals to the first switch and the second switch to control switching of the first switch and the second switch.

[0011] In the embodiment of the application, the first switch and the second switch are provided, so that the switching of the first switch and the second switch can be controlled to execute a single-motor driving working mode or a dual-motor driving working mode according to an actual working condition of the vehicle, the high efficiency area of the motor is more fully utilized by the vehicle power system, the energy consumption of the vehicle is further reduced, the cost is reduced, the power performance and the economy of the system are optimized, the system has high integration, the volume is more compact, and the cost is more optimal.

[0012] In an embodiment of the application, the control module is configured to:

[0013] input a first control signal to the first switch and input a second control signal to the second switch to control the first switch to be closed and the second switch to be opened to execute the single-motor driving working mode;

[0014] input the second control signal to the first switch and input the first control signal to the second switch to control the first switch to be opened and the second switch to be closed to execute the dual-motor parallel driving working mode.

[0015] In the embodiment of the present application, the first switch is controlled to be closed by inputting the first control signal to the first switch, and the second switch is controlled to be opened by inputting the second control signal to the second switch, so that the first motor is not operated and the second motor is operated by controlling the first switch to be closed and the second switch to be opened, that is, the driving system is controlled to operate in the single-motor driving mode.

[0016] In an embodiment of the present application, the control module is connected between the negative output end of the power battery and the second end of the second inverter circuit, and the control module is also electrically connected with the first motor controller to input the duty cycle signal to the first motor controller.

[0017] In the embodiment of the present application, the control module is electrically connected with the first motor controller in addition to being electrically connected with the first switch and the second switch, so that the first inverter circuit and the first motor can form a BOOST circuit (a kind of switching DC boost circuit) when the first motor is not operated to boost the voltage and provide higher voltage for the second motor to operate. At this time, the control module sends the duty cycle signal to the first motor controller, so that the first motor controller controls the duty cycle of the first inverter circuit according to the duty cycle signal to adjust the boosting degree.

[0018] In an embodiment of the present application, the first inverter circuit includes a first bridge arm group, a second bridge arm group and a third bridge arm group; the first bridge arm group includes a first bridge arm and a second bridge arm connected in series, the second bridge arm group includes a third bridge arm and a fourth bridge arm connected in series, and the third bridge arm group includes a fifth bridge arm and a sixth bridge arm connected in series; the first bridge arm includes a first controllable switch tube and a first diode connected in parallel, the second bridge arm includes a second controllable switch tube and a second diode connected in parallel, the third bridge arm includes a third controllable switch tube and a third diode connected in parallel, the fourth bridge arm includes a fourth controllable switch tube and a fourth diode connected in parallel, the fifth bridge arm includes a fifth controllable switch tube and a fifth diode connected in parallel, and the sixth bridge arm includes a sixth controllable switch tube and a sixth diode connected in parallel; a connection point between the first bridge arm and the second bridge arm is connected with a first winding of the first motor; a connection point between the third bridge arm and the fourth bridge arm is connected with a second winding of the first motor; a connection point between the fifth bridge arm and the sixth bridge arm is connected with a third winding of the first motor; the second inverter circuit has the same structure as the first inverter circuit.

[0019] In the embodiment of the present application, the first inverter circuit and the first motor can form a BOOST circuit to boost the voltage by the setting of the first inverter circuit and the connection with the first motor.

[0020] In an embodiment of the present application, the control module includes a first sampling circuit, a second sampling circuit and a microcontroller.

[0021] The first end of the first sampling circuit is connected between the second end of the first inverter circuit and the negative output end of the power battery, and the second end of the first sampling circuit is electrically connected with the microcontroller.

[0022] The first end of the second sampling circuit is connected between the second end of the second inverter circuit and the second end of the first inverter circuit, and the second end of the second sampling circuit is electrically connected with the microcontroller.

[0023] The microcontroller is electrically connected with the first switch and the second switch, and the microcontroller is also electrically connected with the first motor controller.

[0024] In the embodiment of the application, the control module includes the first sampling circuit, the second sampling circuit and the microcontroller, so that the input voltage input into the first inverter circuit can be collected by the first sampling circuit, and the output voltage after passing through the first inverter circuit and the first motor can be collected by the second sampling circuit, so that the microcontroller can determine the boosting degree of the first inverter circuit and the first motor by comparing the output voltage with the input voltage. Meanwhile, the microcontroller can also generate a corresponding duty cycle signal according to the boosting degree, and transmit the duty cycle signal to the first motor controller, so that the first motor controller controls the duty cycle of the first inverter circuit according to the duty cycle signal to adjust the boosting degree.

[0025] In an embodiment of the application, the microcontroller is configured to:

[0026] receive the first voltage collected by the first sampling circuit and the second voltage collected by the second sampling circuit, and output a corresponding duty cycle signal to the first motor controller based on the first voltage and the second voltage, so that the first motor controller controls the switching frequency of the first controllable switch tube and the second controllable switch tube according to the duty cycle signal.

[0027] In the embodiment of the application, the microcontroller is connected with the first sampling circuit and the second sampling circuit, so that the first voltage sampled by the first sampling circuit, i.e. the input voltage input into the first inverter circuit, can be obtained. The second voltage sampled by the second sampling circuit, i.e. the output voltage after passing through the first inverter circuit and the first motor, can also be obtained. Thus, the first voltage and the second voltage can be compared, and a corresponding duty cycle signal can be generated based on the comparison result and transmitted to the first motor controller. So that the first motor controller can control the switching frequency of the first controllable switch tube and the second controllable switch tube according to the duty cycle signal to adjust the second voltage.

[0028] In an embodiment of the application, the system further includes a first capacitor, a second capacitor and a first inductor;

[0029] The first capacitor is connected in parallel with the power battery, and the first capacitor is connected between the first switch and the negative output end of the power battery.

[0030] The second capacitor is connected in parallel with the power battery, and the second capacitor is connected between the first end of the second inverter circuit and the second end of the second inverter circuit.

[0031] The first inductor is connected between the first switch and the third end of the first inverter circuit.

[0032] In the embodiments of the present application, the first capacitor is connected in parallel with the power battery, and the first capacitor is connected between the first switch and the negative output end of the power battery, so that the first capacitor can play a role of energy storage and power supply. Similarly, the second capacitor is connected in parallel with the power battery, and the second capacitor is connected between the first end of the second inverter circuit and the second end of the second inverter circuit, so that the second capacitor can also play a role of energy storage and power supply. By connecting the first inductor between the first switch and the third end of the first inverter circuit, the first motor controller and the first motor can further play a role of voltage boosting. At the same time, the first inductor can also be used for filtering and energy storage.

[0033] To achieve the above object, a second aspect of the embodiments of the present application proposes a thermal management control method, applied to the driving system proposed in any embodiment of the present application, the method comprising:

[0034] obtaining the current temperature of the power battery, and determining whether the current temperature of the power battery is less than a first threshold value;

[0035] When the current temperature of the power battery is less than the first threshold value, calculating the temperature difference between the current temperature of the power battery and the requested temperature;

[0036] According to the temperature difference, determining the target voltage input to the second inverter circuit, and generating a target duty cycle signal according to the target voltage;

[0037] inputting a first control signal to the first switch and a second control signal to the second switch to control the first switch to close and the second switch to open, and inputting the target duty cycle signal to the first motor controller, so that the first motor controller adjusts the voltage input to the second inverter circuit to the target voltage.

[0038] In the embodiment of the present application, when it is detected that the current temperature of the power battery is less than the first threshold value, it indicates that the temperature of the power battery is too low and the power battery needs to be heated. At this time, the target voltage input to the second inverter circuit is determined according to the temperature difference between the current temperature of the power battery and the requested temperature. Thus, the control module can generate a corresponding target duty cycle signal according to the target voltage, and at the same time, by inputting the first control signal to the first switch and the second control signal to the second switch, the first switch can be controlled to be closed and the second switch can be controlled to be opened to control the second motor to be driven alone. At the same time, the target duty cycle signal is input to the first motor controller, so that the first motor controller can adjust the voltage after the first inverter circuit and the first motor (i.e., the voltage input to the second inverter circuit) to the target voltage according to the target duty cycle signal, so that the second motor can work at the target voltage at the non-efficient point, so that the second motor can emit more heat to be utilized by the thermal management system, and the demand of the vehicle on the thermal management system can be reduced, and the cost can be reduced.

[0039] In an embodiment of the present application, determining the target voltage input to the second inverter circuit according to the temperature difference comprises:

[0040] calculating the output current of the power battery according to the temperature difference;

[0041] determining the target voltage input to the second inverter circuit according to the output current of the power battery and the target efficiency point of the second motor working pre-labeled.

[0042] In the embodiment of the present application, according to the temperature difference between the current temperature of the power battery and the requested temperature, the output current of the power battery can be calculated first, and then according to the output current of the power battery and the target efficiency point of the second motor working pre-labeled, the voltage point of the second motor working can be determined, so that the target voltage input to the second inverter circuit can be determined. So that the second motor can work at the voltage corresponding to the poor efficiency point, so that the second motor can emit more heat to be utilized by the thermal management system, and the demand of the vehicle on the thermal management system can be reduced.

[0043] To achieve the above object, a third aspect of the embodiments of the present application proposes a vehicle comprising the driving system according to any one of the embodiments of the present application.

[0044] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 is a structural schematic diagram of a driving system of a dual-motor architecture according to an embodiment of the present application;

[0046] FIG. 2 is a circuit schematic diagram of a dual-motor parallel-serial connection according to an embodiment of the present application;

[0047] Fig. 3 is a structural block diagram of a control module according to an embodiment of the present application;

[0048] Fig. 4 is another circuit schematic diagram of a double-motor parallel-serial connection according to an embodiment of the present application;

[0049] Fig. 5 is a flow chart of a thermal management control method according to an embodiment of the present application;

[0050] Fig. 6 is a flow chart of a step of determining a target voltage input to a second inverter circuit according to a temperature difference according to an embodiment of the present application.

[0051] Reference signs: power battery - 100; first motor controller - 110; first motor - 120; second motor controller - 130; second motor - 140; first switch - 150; second switch - 160; control module - 170; clutch - 180; reducer - 190; first inverter circuit - 111; second inverter circuit - 131; first sampling circuit - 171; second sampling circuit - 172; microcontroller - 173. DETAILED DESCRIPTION

[0052] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0053] It should be noted that although the functional modules are divided in the device schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described can be executed in a manner different from the module division in the device or the order in the flow chart. The terms "first", "second", etc. in the specification and claims and the above-described drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0055] With the increasingly serious energy shortage and environmental pollution, people's demand for energy saving and environmental protection is getting higher and higher. China has successively promulgated a series of green environmental protection policies. Electric vehicles and hybrid electric vehicles driven by power batteries will certainly become the mainstream of the automobile industry. As the core component of pure electric vehicles, the electric drive assembly is developing towards integration, lightweight, high power density and large torsional ratio. In addition to passenger cars, the electric drive axle technology of commercial vehicles has also developed rapidly. At present, the electric drive assembly of heavy commercial vehicles mainly adopts single motor matched with four or six gear AMT (Automated Mechanical Transmission). Its system integration degree is low, and the volume and weight are large. At the same time, there is power interruption during AMT shifting, and the driving experience is poor. In some special vehicles (such as mine trucks), there are safety deficiencies in application. Due to the complex actual use condition of the whole vehicle, the single motor may work in the low efficiency area for a long time, resulting in high energy consumption of the whole vehicle. In addition, some manufacturers are also exploring integrated electric drive axle with double motors, but the reduction ratio is small or a planetary reduction mechanism is added at the wheel side. This kind of structure has poor heat dissipation, especially in the escape condition, which is easy to cause damage to the wheel side planetary mechanism.

[0056] Based on this, the embodiment of the application provides a driving system with a double motor architecture. By setting a first switch and a second switch, the single motor driving mode or the double motor driving mode can be executed by controlling the switching of the first switch and the second switch according to the actual working condition of the whole vehicle, so that the power system of the whole vehicle can make full use of the high efficiency area of the motor, further reduce the energy consumption of the whole vehicle, reduce the cost, optimize the power performance and economy of the system, and the system integration degree is high, the volume is more compact, and the cost is more optimal.

[0057] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of the driving system with a double motor architecture provided by the embodiment of the application. As shown in FIG. 1, the driving system with a double motor architecture includes a power battery 100, a first motor controller 110, a first motor 120, a second motor controller 130, a second motor 140, a first switch 150, a second switch 160, a control module 170, a clutch 180 and a reducer 190. Among them:

[0058] The first motor controller 110 includes a first inverter circuit 111. The first end of the first inverter circuit 111 is electrically connected with the positive output end of the power battery 100 through the second switch 160. The second end of the first inverter circuit 111 is electrically connected with the negative output end of the power battery 100. The third end of the first inverter circuit 111 is electrically connected with the positive output end of the power battery 100 through the first switch 150. Each phase output end of the first inverter circuit 111 is electrically connected with a winding of the first motor 120.

[0059] The second motor controller 130 comprises a second inverter circuit 131, a first end of the second inverter circuit 131 is electrically connected with the positive output end of the power battery 100 through the second switch 160, a second end of the second inverter circuit 131 is electrically connected with the negative output end of the power battery 100, and the second end of the second inverter circuit 131 is also electrically connected with the second end of the first inverter circuit 111, and each phase output end of the second inverter circuit 131 is electrically connected with a winding of the second motor 140 respectively.

[0060] The first motor 120 is connected with a clutch 180, the clutch 180 is connected with a speed reducer 190, the second motor 140 is connected with the speed reducer 190, and the speed reducer 190 is used for being connected with the vehicle wheel end 20.

[0061] The control module 170 is electrically connected with the first switch 150 and the second switch 160, and is used for inputting a control signal to the first switch 150 and the second switch 160 to control switching of the first switch 150 and the second switch 160.

[0062] In the embodiments of the application, the main function of the motor controller is to convert the direct current from the power battery into alternating current, and to control the operation of the drive motor according to the vehicle control instruction. The main functions include: power-on and power-off management, torque control, forward and reverse rotation of the motor, active discharge function, crawling control, hill-hold and zero speed control, anti-shake, energy recovery, thermal management function, etc. The motor controller mainly consists of a main control board, a drive board, IGBT (Insulate-Gate Bipolar Transistor), a current sensor, a support capacitor, a passive discharge resistor, a copper bar, a radiator, a shell, a connector, a wire harness, etc. The main control board is the control core of the motor controller. The main control board circuit includes: main chip circuit, power supply chip circuit, communication circuit, decoder circuit, storage chip circuit, temperature acquisition circuit, signal amplification circuit, PWM (Pulse Width Modulation) output circuit, etc. The drive board is mainly used for controlling, driving and protecting the normal work of IGBT. The drive board circuit includes IGBT high-voltage device driving, storage chip circuit, power supply circuit. IGBT is an insulated gate bipolar transistor, which mainly plays a role in AC-DC conversion in the controller. By turning on and off the sequence of IGBT transistors, direct current is converted into three-phase alternating current to drive the motor. The current sensor is mainly used for detecting the direct current bus and three-phase alternating current. The support capacitor is a thin film capacitor, which is the main element in the drive circuit of the electric vehicle, mainly playing a smoothing role. The support capacitor mainly keeps the voltage fluctuation on the direct current bus within the allowable range in the controller, and prevents the influence of voltage overshoot and transient overvoltage from the direct current bus on IGBT. After the vehicle is powered off, in order to ensure safety, the discharge resistor is needed to discharge the electric quantity of the capacitor in the motor controller. The copper bar is divided into direct current and alternating current copper bars in the motor driver. The direct current copper bar is connected with the direct current high voltage connector and the motor controller thin film capacitor; the alternating current copper bar is connected with the alternating current high voltage connector and the motor controller IGBT. The radiator is the main part of the cooling system of the motor driver, mainly used for cooling the heat loss generated by the power device and components during operation. Generally, the cooling methods are divided into air cooling, forced air cooling and water cooling. Generally, IGBT power modules adopt water cooling, and MOS (Metal-Oxide-Semiconductor) power devices can adopt air cooling or water cooling. The selection of the mode needs to consider the voltage platform. The connector includes a current Hall connector, an external signal transmission connector, and a signal connection connector between the motor controller main control board and the drive board, and a radiator system control connector.

[0063] In the embodiment of the present application, when the first switch 150 is controlled to be closed and the second switch 160 is controlled to be opened, the circuit corresponding to the first motor 120 is not conducted, the first motor 120 does not work, and only the second motor 140 can work normally. The first inverter circuit 111 and the first motor 120 form a BOOST circuit, which can boost the voltage, i.e., can boost the voltage input to the second inverter circuit 131, thereby improving the driving efficiency of the second motor 140. At this time, the vehicle wheel end is driven to rotate by the second motor 140, i.e., the vehicle wheel end is driven to rotate by the single-motor driving mode. In the single-motor driving mode, the clutch 180 is separated, the connection between the first motor 120 and the vehicle wheel end 20 is disconnected, thereby avoiding that the second motor 140 drives the vehicle wheel end 20 to rotate, and the rotating vehicle wheel end 20 in turn drives the non-working first motor 120 to rotate, which can avoid damaging the first motor 120.

[0064] In the embodiment of the present application, when the first switch 150 is controlled to be opened and the second switch 160 is controlled to be closed, the circuits corresponding to the first motor 120 and the second motor 140 are both conducted, the first motor 120 and the second motor 140 can both work normally, at this time, the vehicle wheel end 20 is driven to rotate by the first motor 120 and the second motor 140, i.e., the vehicle wheel end 20 is driven to rotate by the double-motor driving mode. At this time, the clutch 180 is combined, so that the vehicle wheel end 20 can be driven by the first motor 120 and the second motor 140.

[0065] In the embodiment of the present application, when the first motor 120 fails, the second motor 140 can also be used for driving. When the first motor 120 fails, the first motor 120 can be used for driving. The safety of the system can be effectively improved.

[0066] In the embodiment of the present application, the single-motor driving mode or the double-motor driving mode can be respectively executed by the switching of the first switch 150 and the second switch 160, so that the working mode can be flexibly selected according to the actual working condition of the vehicle. For example, when the vehicle is on an uphill road section and needs strong power output, the double-motor driving mode can be selected for driving to meet the power demand. When the vehicle does not need high power but needs to be warmed up, the single-motor driving mode can be selected to reduce energy consumption and meet the economy of the system.

[0067] In the embodiment of the present application, by the circuit design, when the single-motor driving mode is executed, the first inverter circuit 111 and the first motor 120 form a BOOST circuit to play a role of boosting the voltage, i.e., the voltage input to the second inverter circuit 131 can be boosted, thereby improving the driving efficiency of the second motor 140. That is, even if the single-motor driving mode is selected, the driving efficiency of the driving system can be maximized.

[0068] In the embodiment of the present application, the first motor 120 and the second motor 140 are connected in series on the circuit by setting the first switch 150 and the second switch 160, so that the first switch 150 and the second switch 160 can be controlled to perform the single motor driving mode or the double motor driving mode according to the actual working condition of the vehicle, so that the high efficiency area of the motor can be more fully utilized in the vehicle power system, the energy consumption of the vehicle is further reduced, the cost is reduced, the power performance and the economy of the system are optimized, the system integration is high, the volume is more compact, and the cost is more optimal.

[0069] In an embodiment of the present application, the control module 170 is configured to:

[0070] input the first control signal to the first switch 150 and input the second control signal to the second switch 160 to control the first switch 150 to be closed and control the second switch 160 to be opened to perform the single motor driving mode;

[0071] input the second control signal to the first switch 150 and input the first control signal to the second switch 160 to control the first switch 150 to be opened and control the second switch 160 to be closed to perform the double motor parallel driving mode.

[0072] In the embodiment of the present application, the control module 170 can control the first switch 150 to be closed by inputting the first control signal to the first switch 150, and can control the second switch 160 to be opened by inputting the second control signal to the second switch 160. Therefore, the control module 170 can control the first switch 150 to be closed and control the second switch 160 to be opened, so that the first motor 120 does not work and the second motor 140 works, and at the same time, the first motor 120 and the second motor 140 are connected in series on the circuit, and the first inverter circuit 111 and the first motor 120 function as a voltage booster to provide higher input voltage for the second motor 140, that is, the driving efficiency can be improved when the single motor driving mode is performed.

[0073] In the embodiment of the present application, the control module 170 can control the first switch 150 to be opened by inputting the second control signal to the first switch 150, and can control the second switch 160 to be closed by inputting the first control signal to the second switch 160. Therefore, the control module 170 can control the first switch 150 to be opened and control the second switch 160 to be closed, so that the first motor 120 and the second motor 140 both work, and at the same time, the first motor 120 and the second motor 140 are connected in parallel on the circuit, that is, the double motor driving mode can be realized, and since the first motor 120 and the second motor 140 are connected in parallel, one of the motors can drive the vehicle when the other motor fails, so that the safety of the vehicle can be improved.

[0074] In one embodiment of the present application, referring to FIG. 2, which is a schematic diagram of a double-motor series-parallel circuit provided by an embodiment of the present application. As shown in FIG. 2, a first end of a first inverter circuit 111 is electrically connected to a positive output terminal of a power battery 100 through a second switch 160, a second end of the first inverter circuit 111 is electrically connected to a negative output terminal of the power battery 100, a third end of the first inverter circuit 111 is electrically connected to the positive output terminal of the power battery 100 through a first switch 150, and each phase output terminal of the first inverter circuit 111 is electrically connected to a winding of a first motor 120. A first end of a second inverter circuit 131 is electrically connected to the positive output terminal of the power battery 100 through the second switch 160, a second end of the second inverter circuit 131 is electrically connected to the negative output terminal of the power battery 100, the second end of the second inverter circuit 131 is also electrically connected to the second end of the first inverter circuit 111, and each phase output terminal of the second inverter circuit 131 is electrically connected to a winding of a second motor 140. Wherein:

[0075] The first inverter circuit 111 includes a first bridge arm group, a second bridge arm group and a third bridge arm group; the first bridge arm group includes a first bridge arm and a second bridge arm connected in series, the second bridge arm group includes a third bridge arm and a fourth bridge arm connected in series, and the third bridge arm group includes a fifth bridge arm and a sixth bridge arm connected in series. The first bridge arm includes a first controllable switch tube Q1 and a first diode D1 connected in parallel, the second bridge arm includes a second controllable switch tube Q2 and a second diode D2 connected in parallel, the third bridge arm includes a third controllable switch tube Q3 and a third diode D3 connected in parallel, the fourth bridge arm includes a fourth controllable switch tube Q4 and a fourth diode D4 connected in parallel, the fifth bridge arm includes a fifth controllable switch tube Q5 and a fifth diode D5 connected in parallel, and the sixth bridge arm includes a sixth controllable switch tube Q6 and a sixth diode D6 connected in parallel; a connection point between the first bridge arm and the second bridge arm is connected to a first winding L1 of the first motor 120; a connection point between the third bridge arm and the fourth bridge arm is connected to a second winding L2 of the first motor 120; and a connection point between the fifth bridge arm and the sixth bridge arm is connected to a third winding L3 of the first motor 120.

[0076] The second inverter circuit 131 has the same structure as the first inverter circuit, specifically, the second inverter circuit 131 includes a fourth bridge arm group, a fifth bridge arm group and a sixth bridge arm group; the fourth bridge arm group includes a seventh bridge arm and an eighth bridge arm connected in series, the fifth bridge arm group includes a ninth bridge arm and a tenth bridge arm connected in series, and the sixth bridge arm group includes an eleventh bridge arm and a twelfth bridge arm connected in series; the seventh bridge arm includes a seventh controllable switch tube Q7 and a seventh diode D7 connected in parallel, the eighth bridge arm includes an eighth controllable switch tube Q8 and an eighth diode D8 connected in parallel, the ninth bridge arm includes a ninth controllable switch tube Q9 and a ninth diode D9 connected in parallel, the tenth bridge arm includes a tenth controllable switch tube Q10 and a twelfth diode D10 connected in parallel, the eleventh bridge arm includes an eleventh controllable switch tube Q11 and an eleventh diode D11 connected in parallel, and the twelfth bridge arm includes a twelfth controllable switch tube Q12 and a twelfth diode D12 connected in parallel; a connection point between the seventh bridge arm and the eighth bridge arm is connected with a fourth winding L4 of the second motor 140; a connection point between the ninth bridge arm and the tenth bridge arm is connected with a fifth winding L5 of the second motor 140; and a connection point between the eleventh bridge arm and the twelfth bridge arm is connected with a sixth winding L6 of the second motor 140.

[0077] The control module 170 is connected between the negative output end of the power battery 100 and the second end of the second inverter circuit 131, and is also electrically connected with the first motor controller 110, and is also electrically connected with the first switch 150 and the second switch 160.

[0078] It can be understood that the controllable switch tube can be an IGBT, a MOSFET (referred to as a MOS tube, including PMOS and NMOS two types), a SiC MOSFET (silicon carbide MOSFET) and the like.

[0079] In the embodiment of the present application, the control module 170 is electrically connected with the first switch 150 and the second switch 160, so that the series connection or the parallel connection of the first motor 120 and the second motor 140 can be controlled by controlling the switch of the first switch 150 and the second switch 160. Since the control module 170 is arranged between the negative output end of the power battery 100 and the second end of the second inverter circuit 131, when the first switch is closed and the second switch is opened, the boosting degree of the BOOST circuit composed of the first inverter circuit 111 and the first motor 120 can be determined by detecting the size between the input voltage Vin (i.e., the first voltage) input to the first inverter circuit 111 and the output voltage Vout (i.e., the second voltage) after passing through the first inverter circuit 111 and the first motor 120, and a duty cycle signal can be generated and sent to the first motor controller 110, so that the first motor controller adjusts the second voltage by controlling the duty cycle of the first inverter circuit 111, that is, the voltage input to the second inverter circuit 131 can be adjusted. So that the second motor can work at the voltage point corresponding to different efficiency.

[0080] In an embodiment of the present application, referring to FIG. 2, the driving system of the dual-motor architecture shown in FIG. 1 further includes a first capacitor C1, the first capacitor C1 is connected in parallel with the power battery 100, and the first capacitor C1 is connected between the first switch 150 and the negative output end of the power battery 100.

[0081] In the embodiment of the present application, the first capacitor C1 has the functions of energy storage and filtering. By connecting the first capacitor C1 between the first switch 150 and the negative output end of the power battery 100, the electric energy can be stored when the power battery 100 supplies power to the first motor 120 and the second motor 140. Specifically, the first capacitor C1 is connected in parallel across the power battery 100, which mainly serves to reduce the volatility of the circuit voltage to protect the electrical appliances. When the voltage of the power battery 100 decreases, the voltage of the first capacitor C1 also decreases, and the first capacitor C1 discharges; when the voltage of the power battery 100 increases, the voltage of the first capacitor C1 also increases, and the first capacitor C1 charges.

[0082] In an embodiment of the present application, referring to FIG. 2, the driving system of the dual-motor architecture shown in FIG. 1 further includes a second capacitor C2, the second capacitor C2 is connected in parallel with the power battery 100, and the second capacitor C2 is connected between the first end of the second inverter circuit 131 and the second end of the second inverter circuit 131.

[0083] Similarly, in the embodiment of the present application, the second capacitor C2 has the functions of energy storage and filtering. By connecting the second capacitor C2 between the first end of the second inverter circuit 131 and the second end of the second inverter circuit 131, the electric energy can be stored when the power battery 100 supplies power to the first motor 120 and the second motor 140. Specifically, the second capacitor C2 is connected in parallel across the power battery 100, which can mainly reduce the volatility of the circuit voltage and protect the electrical appliances. When the voltage of the power battery 100 drops, the voltage of the second capacitor C2 also drops, and the second capacitor C2 discharges; when the voltage of the power battery 100 rises, the voltage of the second capacitor C2 also rises, and the second capacitor C2 charges.

[0084] In an embodiment of the present application, referring to FIG. 2, the drive system of the dual-motor architecture shown in FIG. 1 further includes a first inductor L, which is connected between the first switch 150 and the third end of the first inverter circuit 111.

[0085] In the embodiment of the present application, by arranging the first inductor L between the first switch 150 and the third end of the first inverter circuit 111, the first inverter circuit 111 and the first motor 120 can further play a role of voltage boosting. The first inductor L can also play a role of filtering and energy storage.

[0086] In an embodiment of the present application, referring to FIG. 3, FIG. 3 is a structural block diagram of a control module provided in the embodiment of the present application. As shown in FIG. 3, the control module 170 includes a first sampling circuit 171, a second sampling circuit 172, and a microcontroller 173. Referring to FIG. 4, FIG. 4 is another circuit schematic diagram of the dual-motor parallel-serial connection provided in the embodiment of the present application. As shown in FIG. 4, the first end of the first sampling circuit 171 is connected between the second end of the first inverter circuit 111 and the negative output end of the power battery 100, and the second end of the first sampling circuit 171 is electrically connected to the microcontroller 173. The first end of the second sampling circuit 172 is connected between the second end of the second inverter circuit 131 and the second end of the first inverter circuit 111, and the second end of the second sampling circuit 172 is electrically connected to the microcontroller 173. The microcontroller 173 is electrically connected to the first switch 150 and the second switch 160, and the microcontroller 173 is also electrically connected to the first motor controller 110.

[0087] In the embodiment of the present application, the first end of the first sampling circuit 171 is connected between the second end of the first inverter circuit 111 and the negative output end of the power battery 100, and the second end of the first sampling circuit 171 is electrically connected with the microcontroller 173, so that the first sampling circuit 171 can collect the input voltage Vin (i.e., the first voltage) input to the first inverter circuit 111 and transmit it to the microcontroller 173. The first end of the second sampling circuit 172 is connected between the second end of the second inverter circuit 131 and the second end of the first inverter circuit 111, and the second end of the second sampling circuit 172 is electrically connected with the microcontroller 173, so that the second sampling circuit 172 can collect the output voltage Vout (i.e., the second voltage) after passing through the first inverter circuit 111 and the first motor 120 and transmit it to the microcontroller 173. Thus, the microcontroller 173 can generate a duty cycle signal according to the first voltage and the second voltage and transmit it to the first motor controller 110. So that the first motor controller 110 can control the duty cycle of the first inverter circuit 111 according to the duty cycle signal to adjust the second voltage.

[0088] In an embodiment of the present application, the microcontroller 173 is configured to:

[0089] receive the first voltage collected by the first sampling circuit 171 and the second voltage collected by the second sampling circuit 172, and output a corresponding duty cycle signal to the first motor controller 110 based on the first voltage and the second voltage, so that the first motor controller 110 controls the switching frequency of the first controllable switch Q1 and the second controllable switch Q2 according to the duty cycle signal.

[0090] In the embodiment of the present application, the first voltage, the second voltage and the duty cycle have the following relationship:

[0091] In the formula, D is the duty cycle, V out is the second voltage, V in is the first voltage.

[0092] It can be seen that by adjusting the duty cycle, the second voltage V out can be adjusted accordingly under the condition that the first voltage V in remains unchanged. For the first inverter circuit 111, the duty cycle of the first inverter circuit 111 can be adjusted by controlling the switching frequency of the first controllable switch Q1 and the second controllable switch Q2. Thus, the microcontroller 173 can adjust the duty cycle of the first inverter circuit 111 by controlling the switching frequency of the first controllable switch Q1 and the second controllable switch Q2, so as to adjust the second voltage V out .

[0093] The embodiment of the present application also provides a vehicle comprising the driving system with the double-motor architecture according to any one of the embodiments of the present application.

[0094] Since the vehicle comprises the driving system with the double-motor architecture according to any one of the embodiments of the present application, the vehicle provided by the present application has the advantages of the driving system, can control the switching of the first switch and the second switch to perform the single-motor driving mode or the double-motor driving mode according to the actual working condition of the vehicle, makes the power system of the vehicle make full use of the high efficiency area of the motor, further reduces the energy consumption of the vehicle, reduces the cost, optimizes the power performance and the economy of the system, and has high system integration and compact size and low cost.

[0095] Referring to FIG. 5, FIG. 5 is a flowchart of the thermal management control method provided by the embodiment of the present application, which is applied to the driving system with the double-motor architecture according to any one of the embodiments of the present application and can be performed by the control module of the driving system, including but not limited to steps S510 to S540.

[0096] In step S510, the current temperature of the power battery is obtained, and it is determined whether the current temperature of the power battery is less than a first threshold value.

[0097] In step S520, when the current temperature of the power battery is less than the first threshold value, the temperature difference between the current temperature of the power battery and a requested temperature is calculated.

[0098] In step S530, the target voltage input to the second inverter circuit is determined according to the temperature difference, and the target duty cycle signal is generated according to the target voltage.

[0099] In step S540, the first control signal is input to the first switch and the second control signal is input to the second switch to control the first switch to be closed and the second switch to be opened, and the target duty cycle signal is input to the first motor controller to make the first motor controller adjust the voltage input to the second inverter circuit to the target voltage.

[0100] The core component of an electric vehicle is a power battery. The main factor affecting the performance of the power battery is temperature. Too high or too low temperature will cause the performance of the power battery to decrease or even endanger the safety of the power battery. High temperature causes the performance of the power battery to decrease or even explode, and the power battery cannot work in a low-temperature environment. These problems always restrict the development of electric vehicles. Therefore, the power battery needs to be managed in terms of heat. An efficient and energy-saving heat management scheme can effectively ensure that the power battery is in an optimal working temperature range, thereby greatly improving the performance and service life of the power battery and ensuring the safe working of the power battery. Therefore, the improvement and development of the heat management technology has become a key technology for further improving the performance of the power battery and developing electric vehicles.

[0101] In the embodiments of the present application, it is considered that too high or too low temperature will lead to performance reduction or even safety hazard of the power battery, and therefore the current temperature of the power battery needs to be acquired in real time, and it is determined whether the current temperature of the power battery is in the optimal working temperature range. When the current temperature of the power battery is too high, the power battery needs to be cooled by the thermal management system to reduce the temperature of the power battery. When the current temperature of the power battery is too low, the power battery needs to be heated by the thermal management system to increase the temperature of the power battery. In the embodiments of the present application, when the temperature of the power battery is too low and the power battery needs to be heated, the driving system of the dual-motor architecture proposed in any embodiment of the present application is controlled to execute the single-motor driving working mode (i.e. driven by the second motor), and the second motor is adjusted to work at a voltage point with poor efficiency, so that more heat generated by the second motor can be utilized by the thermal management system, thereby effectively reducing the demand of the whole vehicle on the thermal management system and reducing the cost.

[0102] Specifically, the current temperature of the power battery is acquired in real time, and it is determined whether the current temperature of the power battery is less than a first threshold value. The first threshold value can be the lower limit value of the optimal working temperature range of the power battery. When the current temperature of the power battery is less than the first threshold value, it indicates that the temperature of the power battery is too low and the power battery needs to be heated. At this time, the demand of the whole vehicle on the thermal management system can be reduced, and the control module needs to control the driving system of the dual-motor architecture to execute the single-motor driving working mode, i.e. the control module needs to input a first control signal to the first switch and a second control signal to the second switch to control the first switch to be closed and the second switch to be opened, so that the first motor does not work and the second motor works. At this time, in order to further improve the heat generation of the second motor, the control module needs to input a target duty cycle signal to the first motor controller, so that the first motor controller controls the voltage input to the second inverter circuit to be a target voltage according to the target duty cycle signal, so that the second motor can work at a voltage point with poor efficiency, so as to improve the heat generation of the second motor. The target duty cycle signal is generated by the control module based on the temperature difference between the current temperature and the requested temperature of the power battery. Specifically, according to the temperature difference between the current temperature and the requested temperature of the power battery, the target voltage input to the second inverter circuit can be determined. Therefore, the control module can generate a target duty cycle signal according to the target voltage input to the second inverter circuit, and transmit it to the first motor controller, so that the first motor controller can control the duty cycle of the first inverter circuit according to the target duty cycle signal, so as to step up the output voltage of the power battery, i.e. the input voltage of the first inverter circuit, so that the output voltage after the first inverter circuit and the first motor, i.e. the voltage input to the second inverter circuit, is the target voltage, so that the second motor works at the corresponding target voltage at the voltage point with poor efficiency, thereby being able to generate more heat to be utilized by the thermal management system.

[0103] Referring to FIG. 6, FIG. 6 is a flowchart of a step of determining the target voltage input to the second inverter circuit according to the temperature difference, provided by the embodiments of the present application, including but not limited to step S610 to step S620.

[0104] In step S610, the output current of the power battery is calculated according to the temperature difference.

[0105] In step S620, the target voltage input to the second inverter circuit is determined according to the output current of the power battery and the at least one target efficiency point of the second motor working pre-labeled.

[0106] In the embodiments of the present application, the influence of temperature on the discharge performance of the battery is directly reflected on the discharge capacity and the discharge voltage. When the temperature decreases, the internal resistance of the battery increases, the electrochemical reaction speed slows down, the polarization internal resistance rapidly increases, the discharge capacity and the discharge platform of the battery decrease, and the output of the battery power and energy is affected. For lithium ion batteries, the discharge capacity sharply decreases under low temperature conditions. Improving the thermal management capability of the battery pack under the low temperature environment of the whole vehicle is a very critical technical problem. The temperature rise of the power battery cell is affected by the cell internal resistance, the current passing through the cell, the environmental temperature and the whole vehicle thermal management system. Specifically, the temperature rise of the power battery cell and the cell internal resistance, the current passing through the cell, the environmental temperature and the multiple coefficients of the whole vehicle thermal management system have the following relationship shown in formula 1:

[0107] In formula 1, I is the output current of the power battery, R is the total internal resistance of the cell, h represents the convection coefficient, m is the mass of the power battery, T is the current temperature of the power battery, T env is the environmental temperature, △t represents the time interval, ΔT represents the temperature rise of the power battery pack after the time interval △t, that is, the temperature difference; Cp represents the specific heat capacity of the power battery, S represents the surface area of the power battery, k represents the temperature rise rate of the whole vehicle thermal management system, and is an offline labeled value, which can be obtained by table lookup according to the temperature value and the request flow during calculation.

[0108] In the embodiments of the present application, after the temperature difference between the current temperature and the request temperature of the power battery is obtained, the output current of the power battery can be calculated according to formula 1. As can be seen from formula 1, under the same driving condition when the temperature is low, increasing the current value of the output current of the power battery can save the heating time of the power battery, that is, the heating efficiency can be improved, so that the demand of the whole vehicle on the thermal management system can be reduced, and the cost of the thermal management system can be reduced.

[0109] In the embodiments of the present application, the efficiency points of the motor under different voltages can be calculated by acquiring the motor operating point (rotational speed n, torque T). Different output currents I of the power battery correspond to different voltage points Vout of the motor operation. In order to reduce the demand of the whole vehicle on the thermal management system, the target voltage input to the second inverter circuit is determined according to the output current of the power battery and the target efficiency point of the second motor operation which is pre-labeled. The target efficiency point of the second motor operation which is pre-labeled is a poor efficiency point, i.e. a non-high efficiency point.

[0110] In the embodiments of the present application, if the current temperature of the power battery is not less than the first threshold, i.e. when the current temperature of the power battery is in the optimal operating temperature interval, the second motor can be controlled to operate at the high efficiency point.

[0111] In the embodiments of the present application, by controlling the target voltage of the second motor operating at the poor efficiency point, the power battery can be heated at a higher heating rate, and at the same time, more heat generated by the second motor can be utilized by the thermal management system, thereby reducing the demand of the whole vehicle on the thermal management system.

[0112] Those skilled in the art can understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and can include more or fewer steps than those shown in the figures, or combine certain steps or different steps.

[0113] The device embodiments described above are only schematic, and the units described as separate components can or can not be physically separate, i.e. can be located in one place or distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0114] Those skilled in the art can understand that all or some of the steps in the above disclosed method, the function modules / units in the system and the device can be implemented as software, firmware, hardware and their appropriate combinations.

[0115] The terms "first", "second", "third", "fourth" and the like (if any) in the specification of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0116] It should be understood that, in the application, "at least one" means one or more, "multiple" means two or more. "And / or" is used to describe the relationship between the associated objects, which means that there can be three relationships, for example, "A and / or B" can represent three cases: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can represent a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0117] In several embodiments provided in the application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, the division of the above units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0118] The units described above as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. According to actual needs, some or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0119] In addition, each functional unit in each embodiment of the application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0120] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes multiple instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program storage media.

[0121] The above describes the embodiments of the embodiments of the present application with reference to the drawings, and does not limit the scope of the embodiments of the present application. Any modifications, equivalent replacements and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of the present application shall be within the scope of the embodiments of the present application.

Claims

1. A dual motor architecture drive system, characterized by, The system comprises a power battery, a first motor controller, a first motor, a second motor controller, a second motor, a first switch, a second switch, a control module, a clutch and a reducer. The first motor controller comprises a first inverter circuit, a first end of the first inverter circuit is electrically connected with a positive output end of the power battery through the second switch, a second end of the first inverter circuit is electrically connected with a negative output end of the power battery, a third end of the first inverter circuit is electrically connected with the positive output end of the power battery through the first switch, and each phase output end of the first inverter circuit is electrically connected with a winding of the first motor. The second motor controller comprises a second inverter circuit, a first end of the second inverter circuit is electrically connected with the positive output end of the power battery through the second switch, a second end of the second inverter circuit is electrically connected with the negative output end of the power battery, the second end of the second inverter circuit is also electrically connected with the second end of the first inverter circuit, and each phase output end of the second inverter circuit is electrically connected with a winding of the second motor. The first motor is connected with the clutch, the clutch is connected with the reducer, the second motor is connected with the reducer, and the reducer is used for being connected with a wheel end of a vehicle. The control module is electrically connected with the first switch and the second switch, and is used for inputting control signals to the first switch and the second switch to control switching of the first switch and the second switch.

2. The system of claim 1, wherein, The control module is configured to: input a first control signal to the first switch and a second control signal to the second switch to control the first switch to be closed and the second switch to be opened, so as to execute a single motor driving working mode; input the second control signal to the first switch and the first control signal to the second switch to control the first switch to be opened and the second switch to be closed, so as to execute a double motor parallel driving working mode.

3. The system of claim 1, wherein, The control module is connected between the negative output end of the power battery and the second end of the second inverter circuit, and the control module is also electrically connected with the first motor controller to input a duty cycle signal to the first motor controller.

4. The system of claim 1, wherein, The first inverter circuit comprises a first bridge arm group, a second bridge arm group and a third bridge arm group; the first bridge arm group comprises a first bridge arm and a second bridge arm connected in series, the second bridge arm group comprises a third bridge arm and a fourth bridge arm connected in series, and the third bridge arm group comprises a fifth bridge arm and a sixth bridge arm connected in series; the first bridge arm comprises a first controllable switch tube and a first diode connected in parallel, the second bridge arm comprises a second controllable switch tube and a second diode connected in parallel, the third bridge arm comprises a third controllable switch tube and a third diode connected in parallel, the fourth bridge arm comprises a fourth controllable switch tube and a fourth diode connected in parallel, the fifth bridge arm comprises a fifth controllable switch tube and a fifth diode connected in parallel, and the sixth bridge arm comprises a sixth controllable switch tube and a sixth diode connected in parallel; a connection point between the first bridge arm and the second bridge arm is connected with a first winding of the first motor; a connection point between the third bridge arm and the fourth bridge arm is connected with a second winding of the first motor; a connection point between the fifth bridge arm and the sixth bridge arm is connected with a third winding of the first motor; and the second inverter circuit has the same structure as the first inverter circuit.

5. The system of claim 4, wherein, The control module comprises a first sampling circuit, a second sampling circuit and a microcontroller; a first end of the first sampling circuit is connected between a second end of the first inverter circuit and a negative output end of the power battery, and a second end of the first sampling circuit is electrically connected with the microcontroller; a first end of the second sampling circuit is connected between a second end of the second inverter circuit and the second end of the first inverter circuit, and a second end of the second sampling circuit is electrically connected with the microcontroller; the microcontroller is electrically connected with the first switch and the second switch, and the microcontroller is also electrically connected with the first motor controller.

6. The system of claim 5, wherein, The microcontroller is configured to: receive a first voltage collected by the first sampling circuit and receive a second voltage collected by the second sampling circuit, and output a corresponding duty cycle signal to the first motor controller based on the first voltage and the second voltage, so that the first motor controller controls a switching frequency of the first controllable switch tube and the second controllable switch tube according to the duty cycle signal.

7. The system of claim 1, wherein, The system further comprises a first capacitor, a second capacitor and a first inductor; the first capacitor is connected in parallel with the power battery, and the first capacitor is connected between the first switch and the negative output end of the power battery; the second capacitor is connected in parallel with the power battery, and the second capacitor is connected between a first end of the second inverter circuit and a second end of the second inverter circuit; the first inductor is connected between the first switch and a third end of the first inverter circuit.

8. A thermal management control method applied to the drive system of any one of claims 1-7, characterized in that, The method comprises: obtaining a current temperature of the power battery and determining whether the current temperature of the power battery is less than a first threshold value; when the current temperature of the power battery is less than the first threshold value, calculating a temperature difference between the current temperature of the power battery and a requested temperature; determining a target voltage input to the second inverter circuit according to the temperature difference, and generating a target duty cycle signal according to the target voltage; The first control signal is input to the first switch and the second control signal is input to the second switch to control the first switch to be closed and the second switch to be opened, and the target duty cycle signal is input to the first motor controller to make the first motor controller adjust the voltage input to the second inverter circuit to the target voltage.

9. The method of claim 8, wherein, The target voltage input to the second inverter circuit is determined according to the temperature difference. The output current of the power battery is calculated according to the temperature difference. The target voltage input to the second inverter circuit is determined according to the output current of the power battery and at least one target efficiency point of the second motor.

10. A vehicle characterized by comprising: The drive system of any one of claims 1-7.

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