Battery heating system, control method thereof and vehicle

Abstract

The invention provides a battery heating system, a control method thereof and a vehicle, and relates to the technical field of vehicle control, and the method comprises the following steps: when a power battery has a pulse heating demand, determining a pulse heating mode of the battery heating system according to a connection state of a charging pile; controlling the conduction states of the first switch module, the second switch module and the third switch module, so that the power battery, the energy storage capacitor, the inverter, the motor and the charging pile are sequentially connected to form a pulse charging and discharging loop of the power battery corresponding to the pulse heating mode; and controlling the duty ratio of the control pulse of each phase of bridge arm in the inverter according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode, and controlling the pulse charging and discharging loop to perform pulse heating on the power battery according to the duty ratio, so that the heating rate of the power battery can be improved; the charging time is shortened, and charging can be realized at low temperature.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, specifically to a battery heating system and its control method, and a vehicle. Background Technology

[0002] In low-temperature conditions, the power batteries of new energy vehicles face problems such as difficulty in charging, low discharge efficiency, and reduced cycle life. Typically, the batteries need to be heated before they can be put into operation. Summary of the Invention

[0003] In view of this, this application provides a battery heating system and its control method, as well as a vehicle, which controls the pulse heating mode of the power battery according to the connection status of the charging pile, and adjusts the duty cycle of each phase bridge arm in the inverter according to the pulse current frequency and pulse current amplitude, thereby improving the heating rate of the power battery, shortening the charging time, and enabling charging at low temperatures.

[0004] To achieve the above objectives, this application provides the following technical solution: a control method for a battery heating system, the battery heating system comprising: a charging pile, a motor controller, and a motor, the motor controller comprising: an inverter, a first switching module, a second switching module, a third switching module, and an energy storage capacitor; a power battery, the first switching module, the energy storage capacitor, the inverter, the motor, the third switching module, and the charging pile are connected sequentially, the second switching module being connected between the power battery and the motor; the control method comprises: when the power battery has a pulse heating requirement, determining the pulse heating mode of the battery heating system according to the connection status of the charging pile; controlling the conduction status of the first switching module, the second switching module, and the third switching module, so that the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile are connected sequentially to form a pulse charging and discharging circuit of the power battery corresponding to the pulse heating mode; controlling the duty cycle of the control pulse of each phase bridge arm in the inverter according to a preset pulse current frequency and pulse current amplitude and the pulse heating mode, and controlling the pulse charging and discharging circuit to pulse heat the power battery according to the duty cycle.

[0005] In one embodiment of this application, determining the pulse heating mode of the battery heating system based on the connection status of the charging pile includes: if the charging pile is connected, the pulse heating mode of the power battery is determined to be a charging pile pulse charging heating mode, wherein the charging pile pulse charging heating mode involves charging the power battery through the charging pile during the charging phase and charging the windings in the motor through the power battery during the discharging phase; if the charging pile is disconnected, the pulse heating mode of the power battery is determined to be a no-charging-pile pulse charge-discharge heating mode, wherein the no-charging-pile pulse charge-discharge heating mode involves charging the energy storage capacitor through the power battery during the discharging phase and charging the power battery through the energy storage capacitor during the discharging phase.

[0006] In one embodiment of this application, controlling the conduction states of the first switch module, the second switch module, and the third switch module to sequentially connect the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile to form a pulse charging and discharging circuit for the power battery corresponding to the pulse heating mode includes: if the pulse heating mode is a charging pile pulse charging and heating mode, controlling the second switch module to open and the first and third switch modules to close, so that the charging pile, the motor, the inverter, and the power battery are sequentially connected to form a first pulse charging and discharging heating circuit; if the pulse heating mode is a non-charging pile pulse charging and discharging heating mode, controlling the second switch module to close and the first and third switch modules to open, so that the power battery, the second switch module, the motor, and the inverter are sequentially connected to form a second pulse charging and discharging heating circuit.

[0007] In one embodiment of this application, the step of controlling the duty cycle of the control pulse of each phase arm in the inverter according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode includes: if the pulse heating mode is a charging pile pulse charging heating mode, generating a pulse demand current according to the preset pulse current frequency and pulse current amplitude; and controlling the duty cycle of the control pulse of each phase arm in the inverter according to the pulse demand current.

[0008] In one embodiment of this application, controlling the duty cycle of the control pulse of each phase arm in the inverter according to the pulse demand current includes: obtaining the phase current of each phase winding of the motor and calculating the sum of the phase currents of each phase winding to obtain the actual charging current; obtaining the deviation current according to the difference between the pulse demand current and the actual charging current; and performing proportional-integral adjustment according to the deviation current to obtain the duty cycle of the control pulse of each phase arm in the inverter.

[0009] In one embodiment of this application, the step of generating a pulse demand current based on a preset pulse current frequency and pulse current amplitude includes: in the charging phase, generating a pulse charging demand current using a square wave signal generator based on a preset pulse current frequency and pulse current amplitude; and in the discharging phase, generating a pulse discharging demand current using a sine wave signal generator based on a preset pulse current frequency and pulse current amplitude.

[0010] In one embodiment of this application, before generating the first pulse demand current using a square wave signal generator according to a preset pulse current frequency and pulse current amplitude, the process includes: controlling the upper arm of at least one phase bridge arm in the inverter to conduct; the charging pile, at least one phase winding in the motor connected to the at least one phase bridge arm, the upper arm of the at least one phase bridge arm, the first switching module, and the power battery are sequentially connected to form a first pulse charging circuit; before generating the second pulse demand current using a sine wave signal generator according to a preset pulse current frequency and pulse current amplitude, the process includes: controlling the upper arm and the lower arm of at least another phase bridge arm in the inverter to conduct; the power battery, the upper arm of at least another phase bridge arm in the inverter, at least another phase winding in the motor connected to the at least another phase bridge arm, the at least one phase winding in the motor, and the lower arm of the at least one phase bridge arm are sequentially connected to form a first pulse discharging circuit.

[0011] In one embodiment of this application, the method further includes: if the power battery has no pulse heating requirement and the charging pile is in a connected state, then the battery heating system is determined to operate in motor drive mode; if the power battery has no pulse heating requirement and the charging pile is in a disconnected state, then the battery heating system is determined to operate in normal charging mode.

[0012] As a second aspect of this application, this application also provides a battery heating system, including: a charging pile, a motor controller, and a motor. The motor controller includes: an inverter, a first switching module, a second switching module, a third switching module, and an energy storage capacitor. A power battery, the first switching module, the energy storage capacitor, the inverter, the motor, the third switching module, and the charging pile are connected in sequence. The second switching module is connected between the power battery and the motor. The motor controller further includes a control circuit, which is used to: determine the pulse heating mode of the battery heating system according to the connection status of the charging pile when the power battery has a pulse heating requirement; control the conduction status of the first switching module, the second switching module, and the third switching module so that the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile are connected in sequence to form a pulse charging and discharging circuit of the power battery corresponding to the pulse heating mode; control the duty cycle of the control pulse of each phase bridge arm in the inverter according to a preset pulse current frequency and pulse current amplitude and the pulse heating mode, and control the pulse charging and discharging circuit to pulse heat the power battery according to the duty cycle.

[0013] As a third aspect of this application, this application also provides a vehicle including the aforementioned battery heating system.

[0014] This application provides a control method for a battery heating system. The battery heating system includes a charging pile, a motor controller, and a motor. The motor controller includes an inverter, a first switch module, a second switch module, a third switch module, and an energy storage capacitor. A power battery, the first switch module, the energy storage capacitor, the inverter, the motor, the third switch module, and the charging pile are connected sequentially. The second switch module is connected between the power battery and the motor. The control method includes: when the power battery requires pulse heating, determining the pulse heating of the battery heating system based on the connection status of the charging pile. The system controls the conduction states of the first, second, and third switch modules, enabling the power battery, energy storage capacitor, inverter, motor, and charging pile to be sequentially connected to form a pulse charging and discharging circuit for the power battery corresponding to the pulse heating mode. Based on a preset pulse current frequency and amplitude, and the pulse heating mode, the system controls the duty cycle of the control pulses of each phase arm in the inverter, and controls the pulse charging and discharging circuit to pulse-heat the power battery according to the duty cycle. This improves the power battery heating rate, shortens charging time, and allows charging at low temperatures. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a battery heating system provided in an embodiment of this application.

[0017] Figure 2 This is a flowchart illustrating the control method of the battery heating system provided in an embodiment of this application.

[0018] Figure 3 This is a schematic diagram illustrating the operating mode selection of the battery heating system provided in this application embodiment.

[0019] Figure 4 This is a schematic diagram of another battery heating system provided in an embodiment of this application.

[0020] Figure 5 This is a circuit diagram of a battery heating system provided in an embodiment of this application.

[0021] Figure 6 A schematic diagram of the equivalent motor drive circuit of the battery heating system provided in the embodiments of this application.

[0022] Figure 7 A schematic diagram of the first pulse charge-discharge heating circuit of the battery heating system provided in the embodiments of this application.

[0023] Figure 8 A schematic diagram of the first pulse charging circuit of the battery heating system provided in the embodiments of this application.

[0024] Figure 9 A schematic diagram of the first pulse discharge circuit of the battery heating system provided in the embodiments of this application.

[0025] Figure 10 A schematic diagram of the second pulse charge-discharge heating circuit of the battery heating system provided in the embodiments of this application.

[0026] Figure 11 A schematic diagram of the second pulse discharge circuit of the battery heating system provided in the embodiments of this application.

[0027] Figure 12 A schematic diagram of the second pulse charging circuit of the battery heating system provided in the embodiments of this application.

[0028] Figure 13 This is a schematic diagram of pulse heating current control for a battery heating system provided in an embodiment of this application.

[0029] Figure 14 This is a schematic diagram of the motor controller of the battery heating system provided in an embodiment of this application. Detailed Implementation

[0030] This application provides a battery heating system and its control method, as well as a vehicle. By controlling the pulse heating mode of the power battery according to the connection status of the charging pile, and adjusting the duty cycle of each phase bridge arm in the inverter according to the pulse current frequency and pulse current amplitude, the heating rate of the power battery can be improved, the charging time can be shortened, and charging can be achieved at low temperatures.

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] In low-temperature conditions, new energy vehicles face challenges such as charging difficulties, low discharge efficiency, and reduced cycle life of their power batteries. Typically, the batteries need to be heated before operation. Related technologies often utilize charging stations to charge the power batteries. Without incorporating pulse heating into the battery's operation, pulse heating is achieved through pulsed current flow between the power battery and the energy storage capacitor.

[0033] The technical solution of this application is applicable to the application scenario of heating and charging / discharging power batteries in new energy vehicles. This application provides a battery heating system, including: a charging pile, a motor controller, and a motor. The motor controller includes: an inverter, a first switching module, a second switching module, a third switching module, and an energy storage capacitor. The power battery, the first switching module, the energy storage capacitor, the inverter, the motor, the third switching module, and the charging pile are connected sequentially. The second switching module is connected between the power battery and the motor.

[0034] By controlling the on / off states of the first, second, and third switch modules 15 through the motor controller, different pulse heating circuits can be formed for the power battery. This enables pulse heating of the power battery, improving its heating capacity, providing a fast heating rate, and allowing for battery charging at low temperatures. When the first switch module is closed and the second and third switch modules are open, the power battery, the first switch module, the inverter, and the motor form a motor drive circuit. By adjusting the duty cycle of each phase arm of the inverter, the control signal controlling the motor rotation can be adjusted, thereby regulating the motor's driving force.

[0035] Figure 1 The diagram shown is a structural schematic of a battery heating system provided in an embodiment of this application. Figure 1 As shown, the battery heating system includes a charging pile, a motor controller, and a motor 13. The motor controller includes an inverter 12, a first switch module 11, a second switch module 14, a third switch module 15, and an energy storage capacitor C1. The power battery, the first switch module 11, the energy storage capacitor C1, the inverter 12, the motor 13, the third switch module 15, and the charging pile are connected in sequence. The second switch module 14 is connected between the power battery and the motor 13. The first terminal of the first switch module 11 is connected to the positive terminal of the power battery.

[0036] The first bus terminal of the inverter 12 is connected to the second terminal of the first switching module 11, and the second bus terminal of the inverter 12 is connected to the negative terminal of the power battery. The first terminal of the motor 13 is connected to the midpoint of the bridge arm of the inverter 12. The first terminal of the second switching module 14 is connected to the positive terminal of the power battery and the first terminal of the first switching module 11, and the second terminal of the second switching module 14 is connected to the second terminal of the motor 13. The first terminal of the energy storage capacitor C1 is connected to the second terminal of the first switching module 11 and the first bus terminal of the inverter 12, and the second terminal of the energy storage capacitor C1 is connected to the second bus terminal of the inverter 12. The first terminal of the third switching module 15 is connected to the second terminal of the second switching module 14 and the second terminal of the motor 13. The first terminal of the charging pile is connected to the second terminal of the third switching module 15, and the second terminal of the charging pile is connected to the negative terminal of the power battery and the second bus terminal of the inverter 12.

[0037] The control circuit controls the different on / off states of the first switch module 11, the second switch module 14, and the third switch module 15, which can form different pulse heating circuits for the power battery. This enables pulse heating of the power battery, improves its heating capacity, provides a fast heating rate, and allows for battery charging at low temperatures.

[0038] In this configuration, the first end of the first phase winding L1 of the motor 13 is connected to the midpoint of the first phase bridge arm in the inverter 12; the first end of the second phase winding L2 of the motor 13 is connected to the midpoint of the second phase bridge arm in the inverter 12; and the first end of the third phase winding L3 of the motor 13 is connected to the midpoint of the third phase bridge arm in the inverter 12. The second ends of the first phase winding L1, the second phase winding L2, and the third phase winding L3 of the motor 13 are connected together to form the neutral point of the motor.

[0039] The first, second, and third phase bridge arms of inverter 12 each include an upper bridge arm and a lower bridge arm. The upper bridge arm of the first phase bridge arm includes a first switch S1 and a diode connected in parallel with the first switch S1. The upper bridge arm of the second phase bridge arm includes a second switch S2 and a diode connected in parallel with the second switch S2. The upper bridge arm of the third phase bridge arm includes a third switch S3 and a diode connected in parallel with the third switch S3. The lower bridge arm of the first phase bridge arm includes a fourth switch S4 and a diode connected in parallel with the fourth switch S4. The lower bridge arm of the second phase bridge arm includes a fifth switch S5 and a diode connected in parallel with the fifth switch S5. The lower bridge arm of the third phase bridge arm includes a sixth switch S6 and a diode connected in parallel with the sixth switch S6. The midpoint of the first phase bridge arm is the intermediate connection point connecting the first switch S1 and the fourth switch S4. The midpoint of the second phase bridge arm is the intermediate connection point connecting the second switch S2 and the fifth switch S5. The midpoint of the third phase bridge arm is the intermediate connection point connecting the third switch S3 and the sixth switch S6.

[0040] The battery heating system provided in this application embodiment further includes a control circuit, which is used for: When the power battery requires pulse heating, the pulse heating mode of the battery heating system is determined according to the connection status of the charging pile. Controlling the conduction states of the first switch module, the second switch module, and the third switch module enables the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile to be sequentially connected to form a pulse charging and discharging circuit for the power battery corresponding to the pulse heating mode; The duty cycle of the control pulses of each phase bridge arm in the inverter is controlled according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode, and the pulse charging and discharging circuit is controlled to pulse heat the power battery according to the duty cycle.

[0041] The control circuit controls the first switch module 11 and the third switch module 15 to close. The power battery, the energy storage element, the inverter, the motor, and the charging pile are connected in sequence to form a pulse charging and discharging circuit for the power battery. By controlling the pulse heating mode of the power battery according to the connection status of the charging pile, and adjusting the duty cycle of each phase bridge arm in the inverter according to the pulse current frequency and pulse current amplitude, the heating rate of the power battery can be improved, the charging time can be shortened, and charging can be achieved at low temperatures.

[0042] For more specific control methods of the battery heating system, please refer to the control method examples below.

[0043] Based on the above battery heating system, this application provides a control method for the battery heating system, such as... Figure 2As shown, the control method of the battery heating system includes: Step S11: When the power battery has a pulse heating requirement, the pulse heating mode of the battery heating system is determined according to the connection status of the charging pile.

[0044] The Battery Management System (BMS) of the power battery performs a self-test, acquiring information such as the battery temperature and state of charge (SOC) to determine if the battery requires pulse heating. If the battery temperature is below a temperature threshold and the current SOC is below the SOC threshold, then the battery requires pulse heating; otherwise, the battery does not require pulse heating.

[0045] If the power battery requires pulse heating, the battery management system also determines whether a charging pile is connected and determines the pulse heating mode of the battery heating system based on the connection status of the charging pile. The pulse heating modes of the power battery in the battery heating system include a low-temperature charging pile pulse charge / discharge heating mode and a pulse heating mode without a charging pile. The battery heating system can be controlled to operate in one of these heating modes by controlling the conduction states of the first, second, and third switch modules.

[0046] Step S12: Control the conduction state of the first switch module, the second switch module and the third switch module, so that the power battery, the energy storage capacitor, the inverter, the motor and the charging pile are connected in sequence to form a pulse charging and discharging circuit of the power battery corresponding to the pulse heating mode.

[0047] When the battery heating system operates in the low-temperature charging pile pulse charge-discharge heating mode, the first switch module 11 and the third switch module 15 can be closed by the control circuit, and the second switch module 14 can be opened. The charging pile, the third switch module 15, the motor 13, the inverter 12, the first switch module 11 and the power battery are connected in series to form the first pulse charge-discharge heating circuit.

[0048] When the battery heating system operates in the pulse heating mode without a charging pile, the second switch module is closed by the control circuit, and the first switch module and the third switch module are opened. The power battery, the second switch module, the motor and the inverter are connected in series to form the second pulse charging and discharging heating circuit.

[0049] Step S13: Control the duty cycle of the control pulse of each phase bridge arm in the inverter according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode, and control the pulse charging and discharging circuit to pulse heat the power battery according to the duty cycle.

[0050] The target values ​​for the pulse current frequency and amplitude are related to the hardware characteristics of the power battery, motor, and motor controller, and can be obtained through bench testing. The pulse current used for power battery pulse heating varies depending on the pulse heating mode. For example, when the battery heating system operates in the low-temperature charging pile pulse charge / discharge heating mode, a square wave pulse current is used to pulse heat the power battery. When the battery heating system operates in the no-charging-pile pulse heating mode, a sinusoidal wave pulse current is used. A sinusoidal or square wave current is generated based on the preset pulse current frequency and amplitude. The duty cycle of the control pulses for each phase bridge arm in the inverter can be controlled based on the sinusoidal or square wave current, thereby controlling the corresponding pulse charge / discharge circuit to pulse heat the power battery.

[0051] In this embodiment, when the power battery requires pulse heating, the pulse heating mode of the battery heating system is determined according to the connection status of the charging pile; the conduction states of the first switch module, the second switch module, and the third switch module are controlled, so that the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile are sequentially connected to form a pulse charging and discharging circuit of the power battery corresponding to the pulse heating mode; the duty cycle of the control pulse of each phase bridge arm in the inverter is controlled according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode, and the pulse charging and discharging circuit is controlled to pulse heat the power battery according to the duty cycle, thereby realizing the regulation of the current of the charging and discharging circuit.

[0052] The battery heating system in this embodiment can operate in motor drive mode or in power battery pulse heating mode, i.e., pulse heating and charging / discharging of the power battery. Therefore, the operational requirements of the battery heating system need to be determined first. If heating and charging / discharging of the power battery is required, the vehicle needs to be adjusted accordingly to facilitate the battery heating system entering the power battery heating and charging / discharging state.

[0053] Since heating of a power battery is typically achieved through charging and discharging cycles, if the vehicle is connected to a charging station, the charging station can be used for pulse heating of the power battery. Therefore, in this embodiment, optionally, if the charging station is connected, the pulse heating mode of the power battery is determined to be a charging station pulse charging heating mode, where the charging phase involves charging the power battery through the charging station, and the discharging phase involves charging the windings in the motor through the power battery; if the charging station is not connected, the pulse heating mode of the power battery is determined to be a no-charging-station pulse charging and discharging heating mode, where the discharging phase involves charging the energy storage capacitor through the power battery, and the discharging phase involves charging the power battery through the energy storage capacitor.

[0054] If the charging pile is connected, the pulse heating mode of the power battery can be determined as the charging pile pulse charging heating mode, and the charging of the power battery by the connected charging pile can be applied to the pulse heating process of the power battery. The charging pile pulse charging heating mode involves charging the power battery through the charging pile during the charging phase, specifically by the charging pile's Boost discharge to charge the power battery and energy storage capacitor C1. During the discharging phase, the power battery charges the windings in the motor, specifically by controlling the power battery and energy storage capacitor C1 to discharge and charge the three-phase inductor of the motor. These two processes are repeated cyclically to achieve cyclic charging and discharging of the power battery, resulting in battery heating. The charging pile charges the power battery in the form of a square wave current; that is, the target current in the first pulse charging and discharging heating circuit is a square wave. A high effective value of the square wave current can improve the battery pack heating rate and shorten the charging time.

[0055] If the charging pile is not connected, the pulse heating mode of the power battery can be defined as a pulse charge-discharge heating mode without a charging pile. This involves cyclically charging and discharging the power battery with energy storage elements, including an energy storage capacitor and the three-phase windings of the motor, to achieve pulse heating. In this mode, during the discharge phase, the power battery charges the energy storage capacitor. Specifically, the power switching transistors in the inverter control the power battery's Boost discharge to charge the energy storage capacitor C1. During the discharge phase, the energy storage capacitor charges the power battery. Specifically, the energy storage capacitor C1's Buck discharge controls the power battery's charge-discharge. These two processes are repeated cyclically to achieve cyclic charging and discharging of the power battery, resulting in battery heating.

[0056] Considering that the power battery may not require pulse heating, the battery heating system can operate in other modes, such as motor drive mode or normal charging mode of the power battery. Based on this, in this embodiment, optionally, the control method further includes: if the power battery does not require pulse heating and the charging pile is connected, then the battery heating system is determined to operate in motor drive mode; if the power battery does not require pulse heating and the charging pile is not connected, then the battery heating system is determined to operate in normal charging mode.

[0057] If the power battery does not require pulse heating and the charging station is connected, the power battery can be charged directly using the charging station, and the battery heating system will operate in motor drive mode. If the power battery does not require pulse heating and the charging station is not connected, the battery heating system can operate in motor drive mode, using the motor to drive the relevant loads in the vehicle.

[0058] Battery heating system operating mode selection, such as Figure 3 As shown, it includes: Step 100: Battery self-test status.

[0059] The battery management system (BMS) of the power battery performs self-tests and obtains information such as the battery temperature and state of charge (SOC).

[0060] Step 101: Determine if pulse heating is required. If yes, proceed to step 102; otherwise, proceed to step 106.

[0061] The requirement for pulse heating in the power battery is determined based on its state. If the battery temperature is below a certain threshold and the current state of charge (SOC) is also below that threshold, then the power battery requires pulse heating; otherwise, it does not.

[0062] Step 102: Determine if a charging station is connected. If yes, proceed to step 103; otherwise, proceed to step 104.

[0063] If the power battery requires pulse heating, the connection status of the charging pile should be obtained in order to determine the working mode of the battery heating system.

[0064] Step 103: Confirm that the charging pile is in pulse charging heating mode.

[0065] If the power battery requires pulse heating and the charging pile is connected, then the battery heating system will operate in the charging pile pulse charging heating mode.

[0066] Step 104: Determine the mode as pulse charging and discharging heating without a charging pile.

[0067] If the power battery requires pulse heating and the charging pile is not connected, the battery heating system will operate in the pulse charge / discharge heating mode without a charging pile.

[0068] Step 105: Determine if a charging station is connected. If yes, proceed to step 106; otherwise, proceed to step 107.

[0069] If the power battery does not require pulse heating, the connection status of the charging pile should be obtained to determine the operating mode of the battery heating system when pulse heating is not performed.

[0070] Step 106: Confirm normal charging mode.

[0071] If the power battery does not require pulse heating and the charging pile is not connected, then the battery heating system is operating in normal charging mode.

[0072] Step 107: Determine the drive motor operating mode.

[0073] If the power battery does not require pulse heating and the charging pile is not connected, then the battery heating system is operating in normal charging mode.

[0074] In the embodiments of this application, see Figure 4 The battery heating system also includes a fourth switch module 16. The first terminal of the fourth switch module 16 is connected to the second terminal of the charging pile and the negative terminal of the power battery, and the second terminal of the fourth switch module 16 is connected to the second bus terminal of the inverter 12. Before motor driving and power battery pulse heating, the fourth switch module 16 is also controlled to close to form a circuit.

[0075] See Figure 5 The third switch module 15 includes a first control switch K1. The first end of the first control switch K1 is connected to the second end of the second switch module 14 and the second end of the motor 13. The second end of the first control switch K1 is connected to the first end of the charging pile. After the charging pile is connected, the first control switch K1 can be closed to connect the charging pile to the battery heating device, which can provide pulse charging to the power battery to heat it.

[0076] The third switch module 15 further includes a diode D1; the anode of the diode D1 is connected to the first terminal of the first control switch K1, and the cathode of the diode D1 is connected to the second terminal of the second switch module 14 and the second terminal of the motor 13. Diode D1 is an isolation diode; when the power battery is discharging, diode D1 prevents current from flowing back to the charging pile.

[0077] The first switch module 11 includes a second control switch K2, a third control switch K3, and a first resistor R1. The first terminals of the second control switch K2 and the third control switch K3 are connected to the first terminal of the power battery. The second terminal of the second control switch K2 is connected to the first bus terminal of the inverter 12. The second terminal of the third control switch K3 is connected to the first bus terminal of the inverter 12 through the first resistor R1. The first resistor R1 is a pre-charging resistor. The second control switch K2 and the first resistor R1 form a pre-charging circuit. When the battery heating system is working, the energy storage capacitor C1 is pre-charged to prevent damage to components caused by sudden current changes in the motor drive circuit.

[0078] The second switch module 14 includes a fourth control switch K4, the first terminal of which is connected to the positive terminal of the power battery, the first terminal of the second control switch K2, and the first terminal of the third control switch K3, and the second terminal of which is connected to the cathode of the diode D1 and the neutral point of the motor. The fourth switch module 16 includes a fifth control switch K5, the first terminal of which is connected to the second terminal of the charging pile and the negative terminal of the power battery, and the second terminal of which is connected to the second bus terminal of the inverter 12.

[0079] In this embodiment, when the first switch module 11 is closed and the second switch module 14 and the third switch module 15 are open, i.e., the first control switch K1, the fourth control switch K4, and the third control switch K3 are open, and the second control switch K2 and the fifth control switch K5 are closed, the power battery, the first switch module 11, the inverter 12, and the motor 13 form a motor drive circuit. The equivalent circuit of the resulting motor drive circuit is as follows: Figure 6 As shown, by adjusting the duty cycle of each phase arm of the inverter, the control signal controlling the motor rotation can be adjusted, thereby achieving the adjustment of the motor's driving force.

[0080] After determining the pulse heating mode of the power battery in the battery heating system, the conduction states of each control switch in the first, second, and third switch modules are controlled to make the battery heating system operate in the corresponding pulse heating mode. Optionally, if the pulse heating mode is a charging pile pulse charging heating mode, the second switch module is opened, and the first and third switch modules are closed, connecting the charging pile, the motor, the inverter, and the power battery sequentially to form a first pulse charging and discharging heating circuit. That is, the motor controller controls the first control switch K1, the second control switch K2, and the fifth control switch K5 to close, while the third control switch K3 and the fourth control switch K4 are opened, resulting in... Figure 7The first pulse charge-discharge heating circuit is shown.

[0081] The first pulse charge-discharge heating circuit includes a first pulse charging stage where the charging pile charges the power battery and a first pulse discharging stage where the power battery charges at least one phase winding in the motor. When the power battery is in the first pulse charging stage, the charging pile, the third switching module, at least one phase winding in the motor, the upper bridge arm of at least one phase bridge arm in the inverter corresponding to the at least one phase winding, the first switching module, and the power battery are sequentially connected to form the first pulse charging circuit. For example... Figure 8 The current flows out through the positive terminal of the charging pile, through the first phase winding L1, through the first switch S1 of the upper arm of the first phase bridge arm, through the power battery, and back to the negative terminal of the charging pile, forming the first pulse charging circuit. It should be noted that the second switch S2 of the upper arm of the second phase bridge arm and / or the third switch S3 of the upper arm of the third phase bridge arm in the inverter 12 can also be controlled to conduct. That is, the charging pile can form the first pulse charging circuit by controlling the upper arm of any one phase bridge arm or any two phase bridge arms in the inverter 12 to charge the power battery and the energy storage capacitor C1.

[0082] After the power battery and energy storage capacitor C1 are fully charged, the power battery enters the discharge phase. During the first pulse discharge phase, the power battery, the first switching module, the upper arm of at least one other phase bridge arm in the inverter, the at least one other phase winding in the motor connected to the at least one other phase bridge arm, the at least one phase winding in the motor, and the lower arm of the at least one phase bridge arm in the inverter are sequentially connected to form the first pulse discharge circuit. (See also...) Figure 9 The motor controller controls the fourth switch S4 of the lower arm of the first phase bridge arm and the second switch S2 of the upper arm of the second phase bridge arm to conduct. Current flows out from the positive terminal of the power battery, passes through the second switch S2 of the upper arm of the second phase bridge arm, the second phase winding L2, the first phase winding L1, and the fourth switch S4 of the lower arm of the first phase bridge arm, and returns to the negative terminal of the power battery, forming the first pulse discharge circuit.

[0083] In this circuit, the lower bridge arm that is conducting in the first pulse discharge circuit and the lower bridge arm that is conducting in the first pulse charging circuit belong to the same phase bridge arm, while the lower bridge arm and the upper bridge arm that are conducting in the first pulse discharge circuit belong to different phase bridge arms. If the upper bridge arm of the first phase bridge arm in the first pulse charging circuit is conducting, then the lower bridge arm of the first phase bridge arm, as well as the upper bridge arm of the second phase bridge arm and / or the upper bridge arm of the third phase bridge arm, are conducting in the first pulse discharge circuit. If the upper bridge arms of the first and second phase bridge arms in the first pulse charging circuit are conducting, then in the first pulse discharge circuit, the lower bridge arms of the first and second phase bridge arms are controlled to conduct, and the upper bridge arm of the third phase bridge arm is simultaneously controlled to conduct.

[0084] The first pulse charging circuit and the first pulse discharging circuit are cyclically connected to achieve pulse heating of the power battery. The charging pile participates in the pulse heating process of the power battery, and the first pulse charging and discharging heating circuit adopts a low-temperature charging pile pulse charging and discharging heating mode. Since the charging current of the charging pile to the power battery is greater than the discharging current of the power battery, pulse heating of the power battery based on the first pulse charging and discharging heating circuit can improve the battery pack heating rate and shorten the charging time. In the first pulse charging and discharging heating circuit, square wave control is used. When the charging pile charges the power battery, the current is greater than the current in the reverse direction; that is, the current in the first pulse charging circuit is greater than the current in the first pulse discharging circuit. This can improve the battery pack heating rate, shorten the charging time, reduce costs, increase efficiency, and enable charging at low temperatures.

[0085] If the pulse heating mode is a pulse charge / discharge heating mode without a charging pile, the second switch module is closed, and the first and third switch modules are opened, so that the power battery, the second switch module, the motor, and the inverter are connected in sequence to form a second pulse charge / discharge heating circuit. That is, the motor controller controls the fourth control switch K4 and the fifth control switch K5 to close, and the other control switches to open, resulting in the corresponding equivalent circuit as follows: Figure 10 As shown, the second pulse charge-discharge heating circuit is a Buck / Boost bidirectional buck-boost circuit.

[0086] The second pulse charge / discharge heating circuit includes a second pulse charging stage and a second pulse discharging stage. When the power battery is in the second pulse discharging stage, the power battery, the second switching module, at least one phase winding of the motor, the upper bridge arm of at least one phase bridge arm of the inverter corresponding to the at least one phase winding, and the energy storage capacitor are connected in series to form a second pulse discharging circuit. See, for example... Figure 11 Taking a single-phase winding as an example, the boost current flow involves two processes. The first stage is described in [link to documentation]. Figure 11 a) Current flows out from the positive terminal of the power battery, sequentially through the first phase winding L1, the fourth switch S4 of the lower bridge arm of the first phase bridge arm, and returns to the negative terminal of the power battery. (See the second stage for details.) Figure 11 b. Current flows out from the positive terminal of the power battery, sequentially through the first phase winding L1, the first switch S1 of the upper arm of the first phase bridge arm, and the energy storage capacitor C1, before returning to the negative terminal of the power battery. It should be noted that the multi-phase windings in the motor 13 can be controlled to connect to the second pulse discharge circuit. For example, the upper arms of any two phase bridge arms in the inverter 12 can be controlled to conduct, thereby connecting the two phase windings connected to these two phase bridge arms to the second pulse discharge circuit. The power battery charges the energy storage capacitor C1 through the branch containing these two phase windings.

[0087] After the power battery completes charging the energy storage capacitor C1, it can control the energy storage capacitor C1 to charge the power battery, i.e., the power battery enters the charging stage. When the power battery is in the second pulse charging stage, the energy storage capacitor, the upper arm of at least one phase bridge arm in the inverter, at least one phase winding of the motor connected to the at least one phase bridge arm, the second switching module, and the power battery are connected in series to form a second pulse charging circuit. See, for example... Figure 12 Taking a single-phase winding as an example, the Buck boost current flow involves two processes. The first stage is described in [link to documentation]. Figure 12 a) Current flows out from the first terminal of the energy storage capacitor C1, passes sequentially through the second switch S2 of the upper arm of the second phase bridge arm and the second phase winding L2 of the power battery, and returns to the second terminal of the energy storage capacitor C1, forming the second pulse charging circuit. (See the second stage for details.) Figure 12 b. The second phase winding L2, the power battery, and the fifth switch S5 of the lower bridge arm of the second phase bridge arm form a circuit.

[0088] It should be noted that the upper bridge arm that is conducting in the second pulse charging circuit and the upper bridge arm that is conducting in the second pulse discharging circuit belong to different phase bridge arms, while the lower bridge arm that is conducting in the second pulse charging circuit and the lower bridge arm that is conducting in the second pulse discharging circuit belong to the same phase bridge arm. If the upper bridge arm of the first phase bridge arm in the second pulse discharging circuit is conducting, then the upper bridge arm of the second phase bridge arm and / or the upper bridge arm of the third phase bridge arm are conducting in the second pulse charging circuit, and the lower bridge arm of the first phase bridge arm can also be conducting. If the upper bridge arms of the first and second phase bridge arms in the second pulse discharging circuit are conducting, then the upper bridge arm of the third phase bridge arm is controlled to conduct in the second pulse charging circuit, and the lower bridge arms of the first and second phase bridge arms can also be controlled to conduct.

[0089] The second pulse discharge circuit and the second pulse charging circuit are cyclically connected to achieve pulse heating of the power battery. When the charging station is not connected, the second pulse charging and discharging heating circuit operates in a no-charging-station pulse heating mode, and the current magnitude does not exceed the power battery's discharge current.

[0090] After determining the pulse heating mode of the power battery and controlling the conduction state of each control switch to generate the first pulse charge-discharge heating circuit or the second pulse charge-discharge heating circuit, it is necessary to control the pulse current in the first pulse charge-discharge heating circuit or the second pulse charge-discharge heating circuit. In this embodiment, the first pulse charge-discharge heating circuit based on the charging pile pulse charging heating mode is described. Optionally, if the pulse heating mode is the charging pile pulse charging heating mode, a pulse demand current is generated according to a preset pulse current frequency and pulse current amplitude; the duty cycle of the control pulse of each phase bridge arm in the inverter is controlled according to the pulse demand current.

[0091] When the pulse heating mode is the charging pile's pulse charging heating mode, in the first pulse charging and discharging heating circuit, the first process involves the charging pile's Boost voltage boosting and discharging to charge the power battery and energy storage capacitor C1, with the charging pile using a square wave pulse current to charge the power battery. The second process involves the power battery and energy storage capacitor C1 discharging to charge the motor's three-phase inductors, with the power battery using a sinusoidal pulse current for discharging. Different pulse heating currents may require different pulse demand currents, which are the target demand currents. The pulse demand current can be generated based on the preset pulse current frequency and amplitude, and then the duty cycle of the control pulses in each phase bridge arm of the inverter can be controlled according to the pulse demand current to achieve adjustment of the pulse heating current.

[0092] Considering that the pulse heating process of the power battery includes a charging phase and a discharging phase, the charging pile uses a square wave pulse current to charge the power battery and energy storage capacitor C1 during the charging phase, and uses a sinusoidal wave pulse current to discharge the power battery and energy storage capacitor C1 to charge the three-phase inductor of the motor during the discharging phase. Therefore, optionally, during the charging phase, a square wave signal generator is used to generate the pulse charging demand current according to a preset pulse current frequency and pulse current amplitude; during the discharging phase, a sinusoidal signal generator is used to generate the pulse discharging demand current according to a preset pulse current frequency and pulse current amplitude.

[0093] To obtain a preset square wave pulse current during the charging phase, a square wave signal generator can be used to generate the pulse charging demand current based on the preset pulse current frequency and amplitude. The pulse current frequency defines the period of the pulse charging demand current, while the pulse current amplitude defines its magnitude. Based on the preset pulse current frequency and amplitude, the waveform of the pulse charging demand current can be accurately defined. Subsequently, based on this pulse charging demand current, the duty cycle of the control pulses for each phase arm of the inverter during the charging phase can be controlled.

[0094] Similarly, to obtain a preset sinusoidal pulse current during the discharge phase, a sinusoidal signal generator can be used to generate the pulse discharge demand current based on the preset pulse current frequency and pulse current amplitude. The pulse current frequency defines the period of the pulse discharge demand current, while the pulse current amplitude defines its magnitude. Based on the preset pulse current frequency and amplitude, the waveform of the pulse discharge demand current can be accurately defined, and subsequently, based on this pulse discharge demand current, the duty cycle of the control pulses for each phase arm of the inverter during the discharge phase can be accurately controlled.

[0095] After obtaining the pulse demand current, the duty cycle of the control pulses of each phase arm in the inverter can be controlled according to the pulse demand current. Optionally, the phase current of each phase winding of the motor is obtained, and the sum of the phase currents of each phase winding is calculated to obtain the actual charging current; the deviation current is obtained according to the difference between the pulse demand current and the actual charging current; proportional-integral regulation is performed according to the deviation current to obtain the duty cycle of the control pulses of each phase arm in the inverter.

[0096] In this embodiment, the battery heating system further includes: a first current sensor A1, a second current sensor A2, and a third current sensor A3; the first current sensor A1 is connected between the midpoint of the first phase winding of the motor and the midpoint of the first phase bridge arm of the inverter 12; the second current sensor A2 is connected between the midpoint of the second phase winding of the motor 13 and the midpoint of the second phase bridge arm of the inverter 12; and the third current sensor A3 is connected between the midpoint of the third phase winding of the motor 13 and the midpoint of the third phase bridge arm of the inverter 12. The first current sensor A1, the second current sensor A2, and the third current sensor A3 are respectively used to detect the current flowing through the first phase winding L1, the second phase winding L2, and the third phase winding L3. Thus, the duty cycle of the control pulse for each phase bridge arm in the inverter can be adjusted according to the detected current, thereby controlling the on and off times of the upper and lower bridge arms in each phase bridge arm based on the duty cycle. This allows for precise control of the current in the first pulse charging and discharging heating circuit, and precise control of the charging and discharging current of the power battery, ensuring a stable charging and discharging current for the power battery.

[0097] The phase currents of each phase winding of the motor are acquired using a first current sensor A1, a second current sensor A2, and a third current sensor A3. The sum of the phase currents of each phase winding is calculated to obtain the actual charging current flowing through the power battery. In this embodiment, the actual charging current needs to be as consistent as possible with the pulse demand current. Therefore, the difference between the pulse demand current and the actual charging current can be calculated to obtain the deviation current. Then, after proportional-integral adjustment based on the deviation current, the duty cycle of the control pulse for each phase bridge arm in the inverter can be directly obtained. Based on the obtained duty cycle, the switching of each switch in the inverter can be controlled, thereby controlling the cyclic operation of the first pulse charging circuit and the first pulse discharging circuit to achieve pulse heating of the power battery.

[0098] See details Figure 13 The pulse demand current Ireq is generated by a square wave generator based on the preset pulse current frequency Rx_iFreq and pulse current amplitude Rx_iAmp. The formula for the pulse demand current Ireq generated by the square wave generator is as follows: Where D is the duty cycle, calibrated empirically, and T is the pulse period, which is the reciprocal of Rx_iFreq. When Ireq=0, the upper branch is triggered, the motor controller is run, and the duty cycle is directly calculated by injecting D-axis to ensure that no torque is generated that causes the motor to rotate.

[0099] A sine wave generator is used to generate the pulse charging current Ireq based on the preset pulse current frequency Rx_iFreq and pulse current amplitude Rx_iAmp. The formula for the pulse charging current Ireq generated by the square wave generator is as follows: .

[0100] When the pulse heating mode Rx_modPulse is 2, it represents a square wave pulse. The first selection switch selects the pulse charging demand current Ireq generated by the output square wave signal generator, and calculates the difference between this and the actual pulse current of the power battery to obtain the deviation current. Then, the proportional controller performs proportional-integral control based on the deviation current to obtain the duty cycle of the control pulse for each phase arm of the inverter. The actual pulse current of the power battery is the sum of the three-phase current values ​​Iabc. Since the pulse heating current is a square wave pulse at this time, meaning the first pulse charging and discharging heating circuit is in the charging stage of the charging pile charging the power battery, the pulse demand current Ireq generated by the square wave signal generator is not 0. Therefore, the control terminal of the second selection switch is 0, and the second selection switch selects the duty cycle (duty) obtained by the output proportional controller. The hardware system controls each switch of the inverter based on the duty cycle, thereby controlling the pulse heating current of the charging pile charging the power battery.

[0101] When the pulse heating mode Rx_modPulse is 1, it represents a sinusoidal pulse. The first selection switch selects the pulse charging demand current Ireq generated by the output sinusoidal signal generator, and calculates the difference between this and the actual pulse current of the power battery to obtain the deviation current. Then, the proportional controller performs proportional-integral control based on the deviation current to obtain the duty cycle of the control pulse for each phase arm of the inverter. Since the pulse heating current is a sinusoidal pulse at this time, the first pulse charging and discharging heating circuit is in the discharge stage of the power battery and energy storage capacitor charging the three-phase inductor of the motor. When the charging pile is connected, the pulse demand current Ireq generated by the sinusoidal signal generator is not 0. Thus, the control terminal of the second selection switch is 0, and the second selection switch selects the duty cycle (duty) obtained by the proportional controller. The hardware system controls the switching transistors of the inverter according to the duty cycle, thereby controlling the pulse heating current of the charging pile charging the power battery. The hardware system is a control model that includes the control logic of the battery, motor, and controller.

[0102] In addition, according to Figure 13If the square wave signal generator has no signal output, the control terminal of the second selection switch is at a high level, selecting to transmit the motor controller's output to the hardware system. Simultaneously, the PI flag bit PIReset of the motor controller is at a high level to clear the PI integration. The Q-axis required current IqReq is 0 to ensure no torque output. The motor controller obtains the duty cycle of the control pulses for each bridge arm of the inverter based on the input rotor position angle the, the three-phase current Iabc, and the D-axis required current. The hardware system controls each switch in the inverter based on the duty cycle output by the motor controller, and transmits the detected rotor position angle the and three-phase current Iabc to the motor controller.

[0103] The motor controller control process is as follows: Figure 14 As shown, the three-phase currents Iabc of the motor undergo Clark transformation to obtain Beta and Alpha. Combined with the rotor position angle the, Park transformation is performed to obtain the D-axis feedback current IdReal and Q-axis feedback current IqReal. The difference between the D-axis demand current IdReq and the D-axis feedback current IdReal is calculated, and after proportional-integral control by the first proportional controller, the Q-axis voltage Vq is output. The difference between the Q-axis demand current IqReq and the Q-axis feedback current IqReal is calculated, and after proportional-integral control by the second proportional controller, the D-axis voltage Vd is output. The D-axis demand current IdReq is the current flowing from the battery to the motor inductor, and its magnitude is related to the motor inductance characteristics. The Q-axis voltage Vq and the D-axis voltage Vd undergo Anti-Park inverse transformation to obtain Valpha and Vbeta, which are then subjected to Space Vector Pulse Width Modulation (SVPWM) to output the duty cycle (duty) of the control pulses for each bridge arm of the inverter.

[0104] The motor controller obtains the duty cycle of the control pulses of each bridge arm of the inverter based on the rotor position angle the of the input motor, the three-phase current Iabc of the motor, and the D-axis demand current.

[0105] In this embodiment, considering that the pulse heating process of the power battery includes a charging stage and a discharging stage, in this embodiment, before generating the first pulse demand current using a square wave signal generator according to a preset pulse current frequency and pulse current amplitude, optionally, the upper bridge arm of at least one phase bridge arm in the inverter is controlled to be turned on; the charging pile, at least one phase winding in the motor connected to the at least one phase bridge arm, the upper bridge arm of the at least one phase bridge arm, the first switching module, and the power battery are sequentially connected to form a first pulse charging circuit. For example, controlling the formation of... Figure 8The current control loop is shown. Before generating the second pulse demand current using a sine wave generator according to a preset pulse current frequency and pulse current amplitude, the upper arm and lower arm of at least one phase bridge arm in the inverter are controlled to conduct; the power battery, the upper arm of at least one phase bridge arm in the inverter, the at least one phase winding in the motor connected to the at least one phase bridge arm, the at least one phase winding in the motor, and the lower arm of the at least one phase bridge arm are sequentially connected to form a first pulse discharge loop. For example, forming Figure 9 The current control loop shown is used to control each phase arm of the inverter to form corresponding pulse current control loops during the charging and discharging phases, thus facilitating the control of the pulse current.

[0106] The control method of the battery heating system in this application embodiment determines the pulse heating mode of the battery heating system according to the connection status of the charging pile when the power battery has a pulse heating requirement; controls the conduction state of the first switch module, the second switch module, and the third switch module, so that the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile are sequentially connected to form a pulse charging and discharging circuit of the power battery corresponding to the pulse heating mode; controls the duty cycle of the control pulse of each phase bridge arm in the inverter according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode, and controls the pulse charging and discharging circuit to pulse heat the power battery according to the duty cycle. By controlling the pulse heating mode of the power battery according to the connection status of the charging pile and adjusting the duty cycle of each phase bridge arm in the inverter according to the pulse current frequency and pulse current amplitude, the heating rate of the power battery can be improved, the charging time can be shortened, and charging can be achieved at low temperatures.

[0107] This application also provides a vehicle, including the above-described battery heating system.

[0108] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0109] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0110] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0111] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0112] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0113] The above description has been given for illustrative and descriptive purposes. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A control method for a battery heating system, characterized in that, The battery heating system includes a charging pile, a motor controller, and a motor. The motor controller includes an inverter, a first switch module, a second switch module, a third switch module, and an energy storage capacitor. The power battery, the first switch module, the energy storage capacitor, the inverter, the motor, the third switch module, and the charging pile are connected in sequence. The second switch module is connected between the power battery and the motor. The control method includes: When the power battery requires pulse heating, the pulse heating mode of the battery heating system is determined according to the connection status of the charging pile. Controlling the conduction states of the first switch module, the second switch module, and the third switch module enables the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile to be sequentially connected to form a pulse charging and discharging circuit for the power battery corresponding to the pulse heating mode; The duty cycle of the control pulses of each phase bridge arm in the inverter is controlled according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode, and the pulse charging and discharging circuit is controlled to pulse heat the power battery according to the duty cycle.

2. The method according to claim 1, characterized in that, Determining the pulse heating mode of the battery heating system based on the connection status of the charging pile includes: If the charging pile is in a connected state, the pulse heating mode of the power battery is determined to be the charging pile pulse charging heating mode. The charging pile pulse charging heating mode is used to charge the power battery through the charging pile during the charging phase and to charge the windings in the motor through the power battery during the discharging phase. If the charging pile is not connected, the pulse heating mode of the power battery is determined to be the pulse charge-discharge heating mode without charging pile. In the pulse charge-discharge heating mode without charging pile, the power battery charges the energy storage capacitor through the discharge phase, and the energy storage capacitor charges the power battery through the discharge phase.

3. The method according to claim 2, characterized in that, The control of the conduction states of the first switch module, the second switch module, and the third switch module, so that the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile are sequentially connected to form a pulse charging and discharging circuit for the power battery corresponding to the pulse heating mode, includes: If the pulse heating mode is the charging pile pulse charging heating mode, the second switch module is controlled to open, and the first switch module and the third switch module are closed, so that the charging pile, the motor, the inverter and the power battery are connected in sequence to form the first pulse charging and discharging heating circuit; If the pulse heating mode is a pulse charge-discharge heating mode without a charging pile, the second switch module is closed, and the first switch module and the third switch module are opened, so that the power battery, the second switch module, the motor and the inverter are connected in sequence to form a second pulse charge-discharge heating circuit.

4. The method according to claim 2, characterized in that, The step of controlling the duty cycle of the control pulses of each phase arm in the inverter according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode includes: If the pulse heating mode is a charging pile pulse charging heating mode, the pulse demand current is generated according to the preset pulse current frequency and pulse current amplitude. The duty cycle of the control pulses in each phase arm of the inverter is controlled according to the pulse demand current.

5. The method according to claim 4, characterized in that, The step of controlling the duty cycle of the control pulse for each phase arm of the inverter according to the pulse demand current includes: Obtain the phase current of each phase winding of the motor, and calculate the sum of the phase currents of each phase winding to obtain the actual charging current; The deviation current is obtained based on the difference between the pulse demand current and the actual charging current; The duty cycle of the control pulse for each phase arm of the inverter is obtained by performing proportional-integral regulation based on the deviation current.

6. The method according to claim 4, characterized in that, The step of generating the pulse demand current based on the preset pulse current frequency and pulse current amplitude includes: During the charging phase, a square wave signal generator is used to generate the pulse charging demand current according to the preset pulse current frequency and pulse current amplitude. During the discharge phase, a sine wave generator is used to generate the pulse discharge current demand based on the preset pulse current frequency and pulse current amplitude.

7. The method according to claim 6, characterized in that, Before generating the first pulse demand current using a square wave signal generator based on the preset pulse current frequency and pulse current amplitude, the process includes: Control the upper arm of at least one phase arm in the inverter to be turned on; The charging pile, the at least one phase winding of the motor connected to the at least one phase bridge arm, the upper bridge arm of the at least one phase bridge arm, the first switch module, and the power battery are sequentially connected to form a first pulse charging circuit; Before generating the second pulse demand current using a sine wave generator based on the preset pulse current frequency and pulse current amplitude, the process includes: Control the upper arm of at least another phase bridge arm and the lower arm of at least one phase bridge arm in the inverter to be turned on; The power battery, the upper arm of at least another phase bridge arm in the inverter, the at least another phase winding in the motor connected to the at least other phase bridge arm, the at least one phase winding in the motor, and the lower arm of the at least one phase bridge arm are sequentially connected to form a first pulse discharge circuit.

8. The method according to claim 1, characterized in that, The method further includes: If the power battery has no pulse heating requirement and the charging pile is connected, then the battery heating system is determined to be operating in motor drive mode. If the power battery does not require pulse heating and the charging pile is not connected, then the battery heating system is determined to be operating in normal charging mode.

9. A battery heating system, characterized in that, The battery heating system includes a charging pile, a motor controller, and a motor. The motor controller includes an inverter, a first switch module, a second switch module, a third switch module, and an energy storage capacitor. The power battery, the first switch module, the energy storage capacitor, the inverter, the motor, the third switch module, and the charging pile are connected in sequence. The second switch module is connected between the power battery and the motor. The motor controller further includes a control circuit, which is used for: When the power battery requires pulse heating, the pulse heating mode of the battery heating system is determined according to the connection status of the charging pile. Controlling the conduction states of the first switch module, the second switch module, and the third switch module enables the power battery, the energy storage capacitor, the inverter, the motor, and the charging pile to be sequentially connected to form a pulse charging and discharging circuit for the power battery corresponding to the pulse heating mode; The duty cycle of the control pulses of each phase bridge arm in the inverter is controlled according to the preset pulse current frequency and pulse current amplitude and the pulse heating mode, and the pulse charging and discharging circuit is controlled to pulse heat the power battery according to the duty cycle.

10. A vehicle, characterized in that, The vehicle includes: the battery heating system as described in claim 9.

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