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: receiving a pulse heating instruction for indicating the battery heating system to perform pulse heating on a power battery in a charging pile pulse heating mode; responding to the pulse heating instruction, acquiring current operation time in a current pulse period for performing pulse heating on the power battery and current actual current of the power battery, and determining current target current according to the current operation time; the duty ratio of the inverter is obtained according to the current target current and the current actual current, on-off of each phase of bridge arm in the inverter is controlled according to the duty ratio, pulse heating is carried out on the power battery, pulse heating between the charging pile and the energy storage capacitor and the battery is achieved through the charging pile and the energy storage capacitor, the pulse current effective value can be effectively increased, and the charging efficiency is improved. The maximum charging effect is kept, so that the heating speed is increased, and meanwhile low-temperature charging can be achieved in the heating process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to a battery heating system, a control method thereof and a vehicle. BACKGROUND

[0002] New energy vehicles have problems such as charging difficulty, low discharging efficiency and cycle life attenuation of power batteries under low temperature conditions, and usually need to heat the batteries before the power batteries work. SUMMARY

[0003] Therefore, the present application provides a battery heating system, a control method thereof and a vehicle, which can effectively improve the effective value of pulse current, maintain maximum charging effect, thereby improving the heating speed, and realize low-temperature charging during the heating process.

[0004] In order to achieve the above purpose, the present application provides the following technical scheme: a control method of 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 switch module, a second switch module, a third switch module and an energy storage capacitor; the charging pile, the third switch module, the energy storage capacitor, the inverter, the motor, the second switch module and a power battery are connected in sequence; the first switch module is connected between the power battery and the inverter; the control method comprises: receiving a pulse heating instruction, the pulse heating instruction being used to instruct the battery heating system to adopt a charging pile pulse heating mode to pulse heat the power battery, wherein the charging pile pulse heating mode refers to controlling the charging pile, the power battery and the energy storage capacitor to cyclically charge and discharge to heat the power battery; in response to the pulse heating instruction, obtaining a current running time in a current pulse period for pulse heating the power battery and a current actual current of the power battery, and determining a current target current according to the current running time; obtaining a duty cycle of the inverter according to the current target current and the current actual current, and controlling the on-off of each phase bridge arm in the inverter according to the duty cycle, so as to pulse heat the power battery.

[0005] In an embodiment of the present application, the current target current is determined according to the current running time, comprising: comparing the current running time with a reference charging time, the reference charging time being a charging time of the charging pile charging the power battery in the current pulse period; if the current running time is less than the reference charging time, determining the current target current as a constant current charging target current; if the current running time is greater than or equal to the reference charging time, determining the current target current as a sinusoidal discharging target current.

[0006] In one embodiment of this application, obtaining the duty cycle of the inverter based on the current target current and the current actual current includes: calculating the difference between the current actual current and the current target current to obtain a deviation current; and performing proportional-integral adjustment on the deviation current to obtain the duty cycle of the control pulse of the inverter.

[0007] In one embodiment of this application, after controlling the on / off state of each phase bridge arm in the inverter according to the duty cycle, the process includes: adding the current running time to the control cycle to obtain a first time, wherein the control cycle refers to the time for one cycle control of each phase bridge arm in the inverter; and updating the current running time according to the first time and the current pulse cycle.

[0008] In one embodiment of this application, updating the current running time according to the first time and the current pulse period includes: comparing the first time with the current pulse period; if the first time is greater than or equal to the current pulse period, then updating the current running time to zero; if the first time is less than the current pulse period, then updating the current running time to the first time.

[0009] In one embodiment of this application, before obtaining the current running time within the current pulse cycle for pulse heating of the power battery and the current actual current of the power battery, the process includes: controlling the conduction state of the first switch module, the second switch module and the third switch module, so that the charging pile, the energy storage capacitor, the inverter, the motor and the power battery are connected in sequence to form a first pulse charging and discharging circuit.

[0010] In one embodiment of this application, controlling the on / off state of each phase bridge arm in the inverter according to the duty cycle includes: controlling the conduction state of each phase bridge arm in the inverter and controlling the charging pile and the energy storage capacitor to charge the power battery through a first pulse charging circuit, wherein the charging pile, the upper bridge arm of the at least one phase bridge arm, the at least one phase winding of the motor connected to the at least one phase bridge arm, and the power battery are sequentially connected to form the first pulse charging circuit; or, controlling the conduction state of each phase bridge arm in the inverter and controlling the power battery to charge the energy storage capacitor through a first pulse discharging circuit, wherein the power battery, the at least one other phase winding of the motor connected to at least another phase bridge arm, the upper bridge arm of the at least another phase bridge arm, and the energy storage capacitor are sequentially connected to form the first pulse discharging circuit.

[0011] In one embodiment of this application, obtaining the current actual current of the power battery includes: obtaining the phase current of each phase winding of the motor; calculating the sum of the phase currents of each phase winding to obtain the current actual current.

[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. The charging pile, the third switching module, the energy storage capacitor, the inverter, the motor, the second switching module, and the power battery are connected in sequence. The first switching module is connected between the power battery and the inverter. The motor controller further includes a control circuit, which is used to: receive a pulse heating command, the pulse heating command being used to instruct the battery heating system to use the charging pile pulse... The charging pile pulse heating mode performs pulse heating on the power battery. Specifically, the charging pile pulse heating mode refers to controlling the charging pile, the power battery, and the energy storage capacitor to cyclically charge and discharge to heat the power battery. In response to the pulse heating command, the system acquires the current operating time and the current actual current of the power battery within the current pulse cycle for pulse heating, and determines the current target current based on the current operating time. Based on the current target current and the current actual current, the system acquires the duty cycle of the inverter, and controls the switching on and off of each phase arm of the inverter based on the duty cycle to pulse heat the power battery.

[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. The charging pile, the third switch module, the energy storage capacitor, the inverter, the motor, the second switch module, and the power battery are connected sequentially. The first switch module is connected between the power battery and the inverter. The control method includes receiving a pulse heating command, which instructs the battery heating system to use a charging pile pulse heating mode to pulse heat the power battery. The charging pile pulse heating mode refers to controlling the charging pile... The power battery and the energy storage capacitor are cyclically charged and discharged to heat the power battery; in response to the pulse heating command, the current running time and the current actual current of the power battery within the current pulse cycle for pulse heating of the power battery are obtained, and the current target current is determined based on the current running time; the duty cycle of the inverter is obtained based on the current target current and the current actual current, and the on / off state of each phase bridge arm in the inverter is controlled based on the duty cycle to pulse heat the power battery. By using the charging pile and energy storage capacitor to achieve pulse heating between the battery and the power battery, the effective value of the pulse current can be effectively improved, the maximum charging effect can be maintained, thereby improving the heating speed, and low-temperature charging can be achieved during the heating process. 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 of another battery heating system provided in an embodiment of this application.

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

[0020] Figure 5 A schematic diagram of the first pulse charge-discharge heating circuit of the battery heating system provided in the embodiments of this application.

[0021] Figure 6 A schematic diagram of the first pulse charging circuit of the battery heating system provided in the embodiments of this application.

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

[0023] Figure 8 This is a schematic diagram of the pulse heating control logic of the battery heating system provided in the embodiments of this application.

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

[0025] Figure 10 A schematic diagram of the equivalent motor drive circuit of the battery heating system provided in the embodiments of this application. Detailed Implementation

[0026] This application provides a battery heating system and its control method, as well as a vehicle. By using a charging pile and energy storage capacitor to achieve pulse heating between the battery and the charging pile, the effective value of the pulse current can be effectively increased, the maximum charging effect can be maintained, thereby increasing the heating speed. At the same time, the heating process can achieve low-temperature charging.

[0027] 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.

[0028] 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.

[0029] The technical solutions of this application are applicable to application scenarios involving heating and charging / discharging power batteries in new energy vehicles. Figure 1 The diagram shown is a structural schematic of a battery heating system provided in an embodiment of this application. Figure 1As shown, the battery heating system includes a charging pile, a motor controller 10, and a motor 13. The motor controller 10 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 charging pile, the third switch module 15, the energy storage capacitor C1, the inverter 12, the motor 13, the second switch module 14, and the power battery are connected in sequence. The first switch module 11 is connected between the power battery and the inverter 12. Specifically, the charging pile, the third switch module 15, the first switch module 11, and the power battery are connected in sequence, and the power battery, the first switch module 11, the energy storage capacitor C1, the inverter 12, the motor 13, and the second switch module 14 are connected in sequence.

[0030] The motor controller further includes a control circuit, the control circuit being used for: The system receives a pulse heating command, which instructs the battery heating system to use a charging pile pulse heating mode to pulse heat the power battery. The charging pile pulse heating mode refers to controlling the charging pile, the power battery, and the energy storage capacitor to cycle through charging and discharging to heat the power battery. In response to the pulse heating command, the system obtains the current running time within the current pulse cycle for pulse heating of the power battery and the current actual current of the power battery, and determines the current target current based on the current running time. The duty cycle of the inverter is obtained based on the current target current and the current actual current, and the switching on and off of each phase bridge arm in the inverter is controlled based on the duty cycle to pulse heat the power battery.

[0031] 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 first switching module 11 and the first bus terminal of the inverter 12. 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The control circuit controls the second switch module 14 and the third switch module 15 to close. The charging pile, the motor, the inverter, the energy storage capacitor, and the power battery are connected in sequence to form a first pulse charging and discharging heating circuit. By controlling the pulse heating mode of the power battery according to the connection status of the charging pile, and adjusting the target pulse current amplitude according to the current battery voltage of the power battery, the duty cycle of each phase bridge arm in the inverter can be accurately adjusted. The pulse current can be adaptively adjusted to maintain the maximum charging effect, which is beneficial to improving the charging rate and heating rate.

[0036] For more specific control methods of the battery heating system, please refer to the control method examples below.

[0037] Based on the above battery heating system, this application provides a control method for a battery heating system, which is applied to the aforementioned control circuit. For example... Figure 2 As shown, the control method of the battery heating system includes: Step S11: Receive a pulse heating command. The pulse heating command is used to instruct the battery heating system to use the charging pile pulse heating mode to pulse heat the power battery. The charging pile pulse heating mode refers to controlling the charging pile, the power battery and the energy storage capacitor to cycle charge and discharge to heat the power battery.

[0038] The Battery Management System (BMS) of the power battery performs self-checks, acquiring data such as battery temperature and State of Charge (SOC). The BMS also determines the connection status of the charging station. If the power battery temperature is too low, or the current SOC is low, pulse heating is required. When the charging station is connected and the battery temperature and SOC are low, a charging station pulse heating mode is used for charging and pulse heating of the power battery. If the charging station is not connected, or the battery SOC is high, the battery heating system can use a charging station-free pulse heating mode to pulse heat the power battery. The charging station pulse heating mode refers to controlling the cyclic charging and discharging of the charging station, the power battery, and the energy storage capacitor to heat the power battery. The charging station-free pulse heating mode refers to controlling the cyclic charging and discharging of the power battery and the energy storage capacitor to heat the power battery.

[0039] After the battery management system determines that the battery heating system is using the charging pile pulse heating mode to heat the power battery, it sends a pulse heating command to instruct the battery heating system to use the charging pile pulse heating mode to pulse heat the power battery. The control circuit receives this pulse heating command to control the heating process of the power battery.

[0040] Step S12: In response to the pulse heating command, obtain the current running time within the current pulse cycle for pulse heating of the power battery and the current actual current of the power battery, and determine the current target current based on the current running time.

[0041] In response to the received pulse heating command, the battery heating system is controlled to use the charging pile pulse heating mode to pulse heat the power battery. Within one pulse cycle, the power battery undergoes one charging and discharging process. The charging phase involves the charging pile and energy storage capacitor charging the power battery first, followed by the discharging phase where the power battery discharges and charges the energy storage capacitor. During the power battery heating process, the current running time within the current pulse cycle of pulse heating is acquired. Based on the current running time, the current stage can be determined, and thus the current target current can be determined.

[0042] Step S13: Obtain the duty cycle of the inverter based on the current target current and the current actual current, and control the on / off state of each phase bridge arm in the inverter based on the duty cycle to pulse heat the power battery.

[0043] The purpose of adjusting the current of the power battery pulse heating is to make the actual heating current of the power battery consistent with the target current. The duty cycle of the inverter can be calculated based on the current target current and the current actual current, thereby controlling the on and off of each phase bridge arm in the inverter to achieve current regulation, effectively improve the effective value of the pulse current, and thus improve the heating speed.

[0044] The control method of the battery heating system in this application embodiment receives a pulse heating command, which instructs the battery heating system to use a charging pile pulse heating mode to pulse heat the power battery. The charging pile pulse heating mode refers to controlling the charging pile, the power battery, and the energy storage capacitor to cyclically charge and discharge to heat the power battery. In response to the pulse heating command, the system obtains the current running time and the current actual current of the power battery within the current pulse cycle for pulse heating, and determines the current target current based on the current running time. Based on the current target current and the current actual current, the system obtains the duty cycle of the inverter, and controls the switching of each phase arm in the inverter based on the duty cycle to pulse heat the power battery. By using a charging pile and energy storage capacitor to achieve pulse heating between the battery and the system, the effective value of the pulse current can be effectively improved, maintaining the maximum charging effect, thereby increasing the heating speed. Simultaneously, the heating process can achieve low-temperature charging.

[0045] In the embodiments of this application, based on Figure 1 The battery heating control system shown has the second switch module and the third switch module connected when the first switch module is disconnected. When the first switch module is disconnected, the charging pile, the motor, the inverter, the energy storage capacitor and the power battery are connected in sequence to form a first pulse charging and discharging heating circuit.

[0046] When the second switch module is closed and the first switch module and the third switch module are open, the power battery, the motor, the inverter and the energy storage capacitor are connected in sequence to form a second pulse charge and discharge heating circuit.

[0047] When the first switch module is closed and the second and third switch modules are open, the power battery, the energy storage capacitor, the inverter, and the motor are connected in sequence to form a motor drive circuit.

[0048] See Figure 3 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.

[0049] The battery heating system of this application embodiment can operate in motor drive mode or power battery pulse heating mode, that is, to perform pulse charging and discharging on the power battery to achieve pulse heating. If pulse heating of the power battery is required, the battery heating system is first controlled and adjusted accordingly to facilitate the battery heating system entering the power battery heating and charging / discharging state.

[0050] In the embodiments of this application, see Figure 4 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 first switch module 11 and the first bus terminal of the inverter 12. 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 system, which can provide pulse charging to the power battery to heat it.

[0051] 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 first switch module 11 and the first bus terminal of the inverter 12. Diode D1 is an isolation diode; when the power battery is discharging, diode D1 prevents current from flowing back into the charging pile and causing a charging pile malfunction.

[0052] 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.

[0053] 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 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 busbar of the inverter 12.

[0054] If the pulse heating mode is the charging pile pulse charging heating mode, the second and third switch modules are closed, and the first switch module is opened. That is, the control circuit controls the first control switch K1, the fourth control switch K4, and the fifth control switch K5 to close, and the second control switch K2 and the third control switch K3 to open, so that the charging pile, the energy storage capacitor, the inverter, the motor, and the power battery are connected in sequence to form a configuration as shown in the image. Figure 5 The first pulse charge-discharge heating circuit is shown. In the charging phase, the charging pile charges the power battery through the charging pile. Specifically, the charging pile and energy storage capacitor C1 charge the power battery through Buck discharge. In the discharging phase, the power battery charges the energy storage capacitor C1 and the windings in the motor. Specifically, the power battery discharges to charge the three-phase inductors of the energy storage capacitor C1 and 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 with a square wave current; that is, the target current in the first pulse charge-discharge heating circuit is a square wave. A high effective value square wave current can improve the battery pack heating rate and shorten the charging time.

[0055] In this embodiment of the application, before obtaining the current running time within the current pulse cycle for pulse heating of the power battery and the current actual current of the power battery, the process includes: controlling the conduction state of the first switch module, the second switch module and the third switch module, so that the charging pile, the energy storage capacitor, the inverter, the motor and the power battery are connected in sequence to form a first pulse charging and discharging circuit.

[0056] Since the pulse heating command specifies that the battery heating system needs to use the charging pile pulse heating mode to pulse heat the power battery, it is first necessary to control the battery heating system to form a first pulse charge-discharge circuit corresponding to the charging pile pulse heating mode. Specifically, the conduction states of the first switch module, the second switch module, and the third switch module can be controlled to connect the charging pile, the energy storage capacitor, the inverter, the motor, and the power battery in sequence to form the first pulse charge-discharge circuit. Subsequently, the current for pulse heating of the power battery can be adjusted based on this first pulse charge-discharge circuit to improve the heating speed.

[0057] 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.

[0058] When the battery heating system uses the charging pile pulse heating mode to pulse heat the power battery, the goal is to control the charging and discharging current of the power battery. This process is divided into two stages. The first stage involves the charging pile and energy storage capacitor C1 charging the power battery through Buck discharge, with a constant current control. The second stage involves the power battery boost discharge, charging the energy storage capacitor C1 and the windings in the motor, with a sinusoidal current control. These two stages are repeated at high frequency to achieve cyclic charging and discharging of the power battery, thus heating the battery. The first stage provides constant current charging to the power battery, and the current magnitude is controllable. The second stage involves the power battery discharging to charge the energy storage capacitor C1, which causes the voltage across C1 to increase. Therefore, the effective current value is related to the hardware characteristics (including the motor controller, energy storage capacitor, and motor inductor), and its effective value is limited. Since the battery heating speed is strongly correlated with the effective current value, to improve the heating speed of the power battery, the effective current value in the first stage must be greater than that in the second stage. This ensures that the total effective current value is greater than the current used for discharging and heating the power battery, thereby achieving both charging and rapid heating during the heating process.

[0059] In this embodiment, to accurately adjust the pulse heating current of the power battery, it is first necessary to accurately obtain the current actual current of the power battery. Therefore, obtaining the current actual current of the power battery includes: obtaining the phase current of each phase winding of the motor; calculating the sum of the phase currents of each phase winding to obtain the current actual current. This can be applied... Figure 5 The first current sensor A1, the second current sensor A2, and the third current sensor A3 in the system detect the phase currents flowing through the first, second, and third phase windings of the motor in real time, respectively. Then, the sum of the three phase currents flowing through the three-phase windings is calculated to obtain the current actual current of the power battery. It should be noted that the direction of each phase current must be considered when performing the summation calculation. If the phase currents are in opposite directions, the difference between the opposite phase current values ​​is calculated; if the directions are the same, the sum of the phase current values ​​is calculated. Figure 5 The first pulse charging and discharging heating circuit shown corresponds to the pulse heating mode of the charging pile. The three-phase winding of the motor is connected in series with the power battery. By calculating the current actual current of the power battery based on the phase current flowing through the three-phase winding of the motor, the current flowing through the power battery can be accurately obtained, which facilitates precise current adjustment in the subsequent pulse heating process of the power battery.

[0060] Considering that the current target current is related to the stage corresponding to the current running time in the pulse cycle, the step of determining the current target current based on the current running time includes: comparing the current running time with a reference charging time, where the reference charging time is the charging time of the charging pile to charge the power battery within the current pulse cycle; if the current running time is less than the reference charging time, then the current target current is determined to be a constant current charging target current; if the current running time is greater than or equal to the reference charging time, then the current target current is determined to be a sinusoidal discharge target current.

[0061] The reference charging time can be set as needed and is not specifically limited here. If the current running time is less than the reference charging time, it indicates that the charging pile and energy storage capacitor C1 are still in the first stage of charging the power battery. Therefore, the current target current can be determined as the constant current charging target current, which is the first target current for the charging pile and energy storage capacitor C1 to charge the power battery. If the current running time is greater than or equal to the reference charging time, it indicates that the charging pile and energy storage capacitor C1 have completed charging the power battery in the current pulse cycle, and the second stage of charging the power battery to energy storage capacitor C1 has begun. Therefore, the current target current can be determined as the sinusoidal discharge target current, which is the second target current for the power battery to charge the energy storage capacitor C1. The first target current is greater than the second target current. The first and second target currents can be set as needed and are not specifically limited here. The formula for the current target current is as follows: in, The target current amplitude for constant current charging. The target current amplitude for sinusoidal discharge. The current running time is T, the pulse period is T, and iFreq is the frequency of the sinusoidal discharge target current, which is the reciprocal of T-T1.

[0062] By adjusting the current for heating the power battery in the charging pile's pulse heating mode in real time, the effective value of the pulse current can be effectively increased, thereby improving the heating speed and maintaining the maximum charging heating effect.

[0063] Considering that a larger inverter duty cycle results in a larger pulse heating current for the power battery in the charging pile's pulse heating mode, the power battery current can be adjusted by regulating the inverter's duty cycle. Therefore, obtaining the inverter's duty cycle based on the current target current and the current actual current includes: calculating the difference between the current actual current and the current target current to obtain the deviation current; and performing proportional-integral adjustment on the deviation current to obtain the duty cycle of the inverter's control pulse. Since the power battery current needs to be adjusted to match the target current for the corresponding stage, the difference between the current target current and the current actual current can be calculated to obtain the difference current. A larger difference current indicates a significant difference between the current actual current and the current target current, requiring a substantial adjustment of the power battery current. A smaller difference current indicates a closer relationship between the current actual current and the current target current, requiring only minor adjustments to the power battery current. Furthermore, a larger change in the inverter's duty cycle results in a greater adjustment range for the power battery current. Therefore, proportional-integral (PI) regulation can be applied to the deviation current to obtain the duty cycle of the inverter's control pulse. This duty cycle can then be used to control the on / off state of each switch in the inverter, thereby regulating the power battery current. In this embodiment, by applying PI regulation based on the difference between the current actual current and the current target current, the duty cycle of the inverter's control pulse is obtained. This allows for accurate adjustment of the power battery's pulse heating current, ensuring the current matches the corresponding target current. This effectively increases the effective value of the pulse current, thereby improving the heating speed and maintaining maximum charging and heating efficiency.

[0064] After determining the duty cycle of the inverter, the on / off state of each phase bridge arm in the inverter can be controlled according to the duty cycle, thereby adjusting the current of the power battery pulse heating to make the current of the power battery consistent with the current target current. In this embodiment, controlling the on / off state of each phase bridge arm in the inverter according to the duty cycle includes: controlling the conduction state of each phase bridge arm in the inverter and controlling the charging pile and the energy storage capacitor to charge the power battery through a first pulse charging circuit, wherein the charging pile, the upper bridge arm of the at least one phase bridge arm, the at least one phase winding of the motor connected to the at least one phase bridge arm, and the power battery are sequentially connected to form the first pulse charging circuit; or, controlling the conduction state of each phase bridge arm in the inverter and controlling the power battery to charge the energy storage capacitor through a first pulse discharging circuit, wherein the power battery, the at least one other phase winding of the motor connected to at least another phase bridge arm, the upper bridge arm of the at least another phase bridge arm, and the energy storage capacitor are sequentially connected to form the first pulse discharging circuit.

[0065] In the embodiments of this application, it is based on Figure 5The first pulse charge / discharge circuit shown controls the on / off state of each phase bridge arm in the inverter. The first pulse charge / discharge heating circuit includes a first pulse charging stage and a first pulse discharging stage. At this time, the second and third switch modules are closed, and the first switch module is open. Since the current target current may be a constant current charging target current or a sinusoidal discharge target current, for example, if the current running time t is less than the reference charging time T1, the current process is the first process of the charging pile and energy storage capacitor C1 charging the power battery. This first process is the first pulse charging stage of the charging pile charging the power battery. The control current for this first process is constant current charging, and the current magnitude is controllable. At this time, the conduction state of each phase bridge arm in the inverter can be controlled, and the charging pile and the energy storage capacitor can be controlled to charge the power battery through the first pulse charging circuit. The charging pile, the upper bridge arm of at least one phase bridge arm, the at least one phase winding of the motor connected to the at least one phase bridge arm, and the power battery are sequentially connected to form the first pulse charging circuit. Specifically, the upper arm of at least one phase bridge arm in the inverter is controlled to be turned on, and the charging pile and the energy storage capacitor are controlled to charge the power battery through the first pulse charging circuit, so that the charging pile, the upper arm of the at least one phase bridge arm, the at least one phase winding of the motor connected to the at least one phase bridge arm, and the power battery are sequentially connected to form the first pulse charging circuit.

[0066] For example Figure 6 Taking the first phase bridge arm in the inverter as an example, controlling the upper bridge arm of the first phase bridge arm in the inverter to conduct, that is, controlling the first switch S1 to conduct, the charging pile, the energy storage capacitor, the first switch S1, the first phase winding L1, and the power battery are connected in sequence to form a first pulse charging circuit. The current flows out from the positive terminal of the charging pile, through the energy storage capacitor C1, the first switch S1 of the upper bridge arm of the first phase bridge arm in the inverter, the first phase winding L1, and the power battery, and returns 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 bridge arm of the second phase bridge arm and / or the third switch S3 of the upper bridge arm of the third phase bridge arm in the inverter 12 can also be controlled to conduct, that is, the charging pile can be controlled to conduct the upper bridge arm of any one phase bridge arm, any two phase bridge arms, or three phase bridge arms in the inverter 12 to form a first pulse charging circuit, and the charging pile and the energy storage capacitor C1 charge the power battery through this first pulse charging circuit.

[0067] After the power battery is fully charged, it enters the discharge phase. The current operating time t is greater than or equal to the reference charging time T1. Currently, it is in the second process of charging the energy storage capacitor C1 from the power battery. This second process is the first pulse discharge stage of the power battery charging the energy storage capacitor C1. This second process causes the voltage across the capacitor to rise, so the effective current value is related to the hardware characteristics (controller capacitor and motor inductor), and the effective current value is limited. At this time, the conduction state of each phase bridge arm in the inverter can be controlled, and the power battery can be controlled to charge the energy storage capacitor through the first pulse discharge circuit. The power battery, the at least one other phase winding in the motor connected to at least another phase bridge arm, the upper bridge arm of the at least other phase bridge arm, and the energy storage capacitor are sequentially connected to form the first pulse discharge circuit. Specifically, the upper bridge arm of at least another phase bridge arm in the inverter is controlled to be turned on, and the power battery is controlled to charge the energy storage capacitor through a first pulse discharge circuit. The power battery, the at least another phase winding in the motor connected to the at least other phase bridge arm, the upper bridge arm of the at least other phase bridge arm, and the energy storage capacitor are sequentially connected to form the first pulse discharge circuit.

[0068] For example, see Figure 7 Taking the second phase bridge arm in the inverter as an example, controlling the upper bridge arm of the second phase bridge arm in the inverter to conduct, that is, controlling the second switch S2 of the upper bridge arm of the second phase bridge arm to conduct, the power battery, the second phase winding L2, the second switch S2, and the energy storage capacitor C1 are connected in sequence to form a first pulse discharge circuit. The current flows out from the positive terminal of the power battery, passes through the second phase winding L2, the second switch S2 of the upper bridge arm of the second phase bridge arm, and the energy storage capacitor C1 in sequence, and returns to the negative terminal of the power battery, forming the first pulse discharge circuit. It should be noted that the first switch S1 of the upper bridge arm of the first phase bridge arm and / or the third switch S3 of the upper bridge arm of the third phase bridge arm in the inverter 12 can also be controlled to conduct, that is, the charging pile can form a first pulse discharge circuit by controlling the upper bridge arm of any one phase bridge arm, any two phase bridge arms, or any three phase bridge arms in the inverter 12 to conduct, and the power battery charges the energy storage capacitor C1 through this first pulse discharge circuit.

[0069] In this embodiment, the current of the power battery is adjusted in real time to match the corresponding target current in any control cycle, which can effectively improve the effective value of the pulse current, thereby increasing the heating speed and maintaining the maximum charging and heating effect.

[0070] Since current regulation is real-time, after completing the current regulation of one control cycle, it is necessary to enter the current regulation of the next control cycle, at which time the current operating time needs to be updated. Based on this, after controlling the on / off of each phase bridge arm in the inverter according to the duty cycle, the process includes: adding the current operating time to the control cycle to obtain a first time, where the control cycle refers to the time for one cycle of control of each phase bridge arm in the inverter; and updating the current operating time according to the first time and the current pulse cycle.

[0071] After completing one control cycle, the current running time is accumulated by adding one control cycle to it. This is calculated by summing the current running time with the time of one control cycle, resulting in a first time, which is the updated current running time. Since the time obtained after adding one control cycle may exceed the current pulse cycle, to accurately determine whether the current process is in the first or second phase, the updated current running time needs to be further adjusted to correspond with the current pulse cycle. Specifically, the current running time can be updated based on the first time and the current pulse cycle. This current running time, being related to the current pulse cycle, allows for accurate determination of whether the current process is in the first or second phase within the current pulse cycle, thus enabling accurate acquisition of the current target current for subsequent current adjustment.

[0072] Considering that the current running time is used to determine which process is currently in the current pulse cycle, and the first time obtained by adding the current running time to the time of a control cycle may exceed the time of the entire current pulse cycle, it is impossible to determine which process is currently in the current pulse cycle. Therefore, further processing of the first time is needed to update the current running time. Based on this, in this embodiment of the application, updating the current running time according to the first time and the current pulse cycle includes: comparing the first time with the current pulse cycle; if the first time is greater than or equal to the current pulse cycle, then updating the current running time to zero; if the first time is less than the current pulse cycle, then updating the current running time to the first time.

[0073] The first time is compared with the current pulse period. If the first time is greater than or equal to the current pulse period, it indicates that the control of the current pulse period has been completed, and the current running time can be updated to zero, signifying the start of control for the next pulse period. If the first time is less than the current pulse period, it means that the first time obtained by adding the current running time to the time of one control cycle is still within the current pulse period. This first time can then be used directly as the current running time to continue the next round of control, i.e., returning to the step of receiving the pulse heating command. By updating the current running time in real time after each control cycle, the obtained current running time is matched with the current pulse period. This allows for accurate determination of whether the current process is in the first or second stage of the current pulse period, thus enabling accurate acquisition of the current target current for subsequent current adjustment.

[0074] For details of the pulse heating control logic in this application embodiment, please refer to [link / reference]. Figure 8 ,include: Step 100: Begin.

[0075] The vehicle control unit (VCU) or battery management system (BMS) acquires information such as the battery temperature, state of charge (SOC), and charging station connection status of the power battery. Based on this information, it determines the pulse heating mode for the battery heating system. If it determines that the battery heating system needs to use the charging station pulse heating mode to heat the power battery, it sends a pulse heating command to the control circuit of the battery heating system. The pulse heating command instructs the battery heating system to use the charging station pulse heating mode to pulse heat the power battery.

[0076] Step 101: Determine whether a pulse heating command has been received. If yes, proceed to step 102; otherwise, repeat step 101.

[0077] After the vehicle controller or battery management system sends a pulse heating command to the control circuit, the control circuit determines whether it receives the pulse heating command. If it determines that the pulse heating command has been received, the battery heating system needs to be controlled to use the charging pile pulse heating mode to pulse heat the power battery. If it determines that the pulse heating command has not been received, the subsequent process is not required, and step 101 is repeated until the pulse heating command is received.

[0078] Step 102: Determine if t < T1. If yes, proceed to step 103; otherwise, proceed to step 104.

[0079] Determine whether the current running time t is less than the reference charging time T1. The reference charging time T1 is the charging time for the charging pile to charge the power battery within the current pulse cycle. If the current running time t is less than the reference charging time T1, it means that the charging pile and energy storage capacitor have not yet completed the charging process for the power battery. If the current running time t is greater than or equal to the reference charging time T1, it means that the charging pile and energy storage capacitor have completed the charging of the power battery and entered the second process of the power battery discharging to the energy storage capacitor.

[0080] Step 103: The current target current is the constant current charging target current. Then proceed to step 105.

[0081] If the current running time t is less than the reference charging time T1, the current process is the first stage of charging the power battery from the charging pile and energy storage capacitor. During this stage, the control current is constant current charging, and the current magnitude is controllable. Therefore, the current target current is determined to be the constant current charging target current.

[0082] Step 104: The current target current is the sinusoidal discharge target current. Then proceed to step 105.

[0083] If the current running time t is greater than or equal to the reference charging time T1, the charging pile and energy storage capacitor have already completed charging the power battery and are currently in the second process of the power battery discharging into the energy storage capacitor. This process, where the battery discharges to charge the capacitor, causes the voltage across the capacitor to rise. Therefore, the effective value of the current is related to the characteristics of the hardware (controller capacitor and motor inductor), and the effective value of the current is finite. Therefore, the current target current is determined to be the sinusoidal discharge target current.

[0084] Step 105: The difference between the current target current and the current actual current is calculated, and the three-phase duty cycle is adjusted and calculated by the PI controller.

[0085] The difference between the current target current and the current actual current is calculated, and the difference current is used for PI controller adjustment calculation to obtain the three-phase duty cycle of the inverter.

[0086] Step 106: Control the on and off of each switch transistor.

[0087] The control of the inverter switches is adjusted according to the duty cycle to make the actual current of the power battery match the current target current, thus completing one control cycle.

[0088] Step 107: t = t + Δt.

[0089] After completing the control adjustment for one control cycle, it is necessary to perform control for the next control cycle. First, update the current running time by adding the current running time to the control cycle time to obtain the updated current running time.

[0090] Step 108: Determine if t ≥ T. If yes, proceed to step 109; otherwise, return to step 101.

[0091] The current running time needs to be within the current pulse period to determine which process it is currently in. However, the updated current running time may exceed the current pulse period. Therefore, it is necessary to further adjust the updated current running time. We can determine whether the updated current running time is greater than or equal to the current pulse period T, and then adaptively adjust the current running time according to the comparison result to match the current pulse period.

[0092] Step 109: t=0.

[0093] If the current running time is greater than or equal to the current pulse period T, then the current running time is updated to 0, that is, the control of the next pulse period begins.

[0094] If the current running time is less than the current pulse period T, it means that the current time is still within the current pulse period and no further update is needed. You can return to step 101 to receive the next pulse heating command for the next control cycle.

[0095] This embodiment of the application can effectively improve the effective value of the pulse current by adjusting the current of the power battery to match the corresponding target current in real time throughout the entire process of the charging pile pulse heating mode, thereby improving the heating speed and maintaining the maximum charging heating effect.

[0096] In this embodiment of the application, the battery heating system can also operate in a pulse heating mode without a charging pile. For example, if the power battery needs pulse heating when the charging pile is not connected, the battery heating system can only operate in the pulse heating mode without a charging pile.

[0097] If the pulse heating mode is a pulse 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 motor, the inverter, and the energy storage capacitor are connected in sequence to form a second pulse charge-discharge heating circuit to pulse heat the power battery. Specifically, the fourth control switch K4 can be closed, and the first, second, and third control switches K1, K2, and K3 can be opened, while the fifth control switch K5 is closed, so that the power battery, the motor, the inverter, and the energy storage capacitor are connected in sequence to form a second pulse charge-discharge heating circuit. Figure 9The second pulse charge / discharge heating circuit is shown. In the pulse charge / discharge heating mode without a charging pile, during the discharge phase, the power battery charges the energy storage capacitor. Specifically, the power switching transistors in the inverter are controlled to achieve Boost discharge of the power battery 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 is controlled to Buck discharge to charge the power battery. The two processes are repeated cyclically to achieve cyclic charging and discharging of the power battery, thereby heating the battery.

[0098] In this embodiment, the second pulse charge-discharge heating circuit is a Buck / Boost bidirectional buck-boost circuit, which consists of two processes. The first process controls the power switch to enable the power battery to charge the energy storage capacitor C1 through Boost voltage boosting discharge. After the capacitor voltage increases, the second process enables the energy storage capacitor C1 to charge the power battery through Buck voltage bucking discharge. The two processes are repeated cyclically to achieve the cyclic charge-discharge of the power battery and heat the battery.

[0099] 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, at least one phase winding of the motor, the upper arm of at least one phase bridge arm in 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. It should be noted that multiple phase windings in the motor 13 can be controlled to connect to the second pulse discharging 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 or three-phase windings connected to these two phase bridge arms to the second pulse discharging circuit. The power battery charges the energy storage capacitor C1 through the branch containing the two-phase or three-phase windings. After the power battery completes charging the energy storage capacitor C1, the energy storage capacitor C1 can be controlled to charge the power battery, i.e., the power battery enters the charging stage. When the power battery is in the second pulse charging phase, 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. The second pulse discharging circuit is a Buck step-down circuit. During operation, it controls the transfer of electrical energy stored in the energy storage capacitor C1 to the power battery to charge it. The second pulse discharging circuit and the second pulse charging circuit are cyclically connected to achieve pulse heating of the power battery. At this time, the charging pile is not connected, and the second pulse charging and discharging heating circuit is in a pulse heating mode without a charging pile, and the current is not greater than the discharge current of the power battery.

[0100] In this embodiment, under extremely low temperature and low state of charge (SOC) conditions, the power battery is directly pulse-charged and discharged using a charging pile, i.e., the power battery is heated using a charging pile pulse heating mode. Considering the risk of damage and lifespan degradation to the power battery due to a large voltage boost ratio, a pulse heating mode without a charging pile is first used to pulse-heat the power battery under extremely low temperature or low SOC conditions. Once the battery temperature rises, the charging pile pulse heating mode is then used to achieve both charging and heating of the power battery. This reduces costs, increases heating speed and efficiency, and allows for charging and heating at low temperatures. Simultaneously, it avoids the risk of battery damage caused by charging pile pulse charging under extremely low temperature and low SOC conditions.

[0101] Considering that the power battery may not require pulse heating, the battery heating system can also operate in other modes, such as motor drive mode or normal charging mode of the power battery. In this embodiment, when the first switch module 11 and the fourth switch module 16 are closed, and the second switch module 14 and the third switch module 15 are open, that is, when the first control switch K1, the third control switch K3, and the fourth control switch K4 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 energy storage capacitor C1, 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 10 As shown, the control signal for controlling the motor rotation can be adjusted by regulating the duty cycle of each phase arm of the inverter, thereby adjusting the motor's driving force. The third control switch K3 and the first resistor R1 form a pre-charging circuit, which pre-charges the energy storage capacitor C1 when the battery heating system is operating in other modes, preventing damage to components caused by sudden current changes in the motor drive circuit.

[0102] In this embodiment, the first switch module 11 and the third switch module 15 can be closed, while the second switch module 14 and the fourth switch module 16 can be opened. That is, the first control switch K1 and the second control switch K2 can be closed, while the third control switch K3, the fourth control switch K4 and the fifth control switch K5 can be opened. The charging pile and the power battery form a circuit, so that the charging pile can directly charge the power battery.

[0103] The control method of the battery heating system in this application embodiment receives a pulse heating command, which instructs the battery heating system to use a charging pile pulse heating mode to pulse heat the power battery. The charging pile pulse heating mode refers to controlling the charging pile, the power battery, and the energy storage capacitor to cyclically charge and discharge to heat the power battery. In response to the pulse heating command, the system obtains the current running time and the current actual current of the power battery within the current pulse cycle for pulse heating, and determines the current target current based on the current running time. Based on the current target current and the current actual current, the system obtains the duty cycle of the inverter, and controls the switching of each phase arm in the inverter based on the duty cycle to pulse heat the power battery. By using a charging pile and energy storage capacitor to achieve pulse heating between the battery and the system, the effective value of the pulse current can be effectively improved, maintaining the maximum charging effect, thereby increasing the heating speed. Simultaneously, the heating process can achieve low-temperature charging.

[0104] This application also provides a vehicle, including the above-described battery heating system.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] The above description has been given for purposes of illustration and description. 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 charging pile, the third switch module, the energy storage capacitor, the inverter, the motor, the second switch module, and the power battery are connected in sequence. The first switch module is connected between the power battery and the inverter. The control method includes: The system receives a pulse heating command, which instructs the battery heating system to use a charging pile pulse heating mode to pulse heat the power battery. The charging pile pulse heating mode refers to controlling the charging pile, the power battery, and the energy storage capacitor to cycle through charging and discharging to heat the power battery. In response to the pulse heating command, the system obtains the current running time within the current pulse cycle for pulse heating of the power battery and the current actual current of the power battery, and determines the current target current based on the current running time. The duty cycle of the inverter is obtained based on the current target current and the current actual current, and the switching on and off of each phase bridge arm in the inverter is controlled based on the duty cycle to pulse heat the power battery.

2. The method according to claim 1, characterized in that, Determining the current target current based on the current running time includes: The current running time is compared with the reference charging time, which is the charging time of the charging pile to charge the power battery within the current pulse cycle; If the current running time is less than the reference charging time, then the current target current is determined to be the constant current charging target current; If the current running time is greater than or equal to the reference charging time, then the current target current is determined to be the sinusoidal discharge target current.

3. The method according to claim 1, characterized in that, The step of obtaining the inverter's duty cycle based on the current target current and the current actual current includes: The difference between the current actual current and the current target current is calculated to obtain the deviation current; The duty cycle of the control pulse of the inverter is obtained by performing proportional-integral regulation on the deviation current.

4. The method according to claim 1, characterized in that, After controlling the on / off state of each phase arm in the inverter according to the duty cycle, the process includes: The current running time is added to the control cycle to obtain the first time. The control cycle refers to the time for one cycle of control of each phase bridge arm in the inverter. The current running time is updated based on the first time and the current pulse period.

5. The method according to claim 4, characterized in that, The step of updating the current running time based on the first time and the current pulse period includes: Compare the first time with the current pulse period; If the first time is greater than or equal to the current pulse period, then the current running time is updated to zero; If the first time is less than the current pulse period, then the current running time is updated to the first time.

6. The method according to claim 1, characterized in that, Before obtaining the current running time within the current pulse cycle for pulse heating of the power battery and the current actual current of the power battery, the process includes: Controlling the conduction states of the first switch module, the second switch module, and the third switch module enables the charging pile, the energy storage capacitor, the inverter, the motor, and the power battery to be connected in sequence to form a first pulse charging and discharging circuit.

7. The method according to claim 1, characterized in that, The control of the on / off state of each phase arm in the inverter according to the duty cycle includes: The inverter controls the conduction state of each phase arm of the inverter and controls the charging pile and the energy storage capacitor to charge the power battery through a first pulse charging circuit. The charging pile, the upper arm of at least one phase arm, at least one phase winding of the motor connected to the at least one phase arm, and the power battery are sequentially connected to form the first pulse charging circuit; or... The inverter controls the conduction state of each phase bridge arm and controls the power battery to charge the energy storage capacitor through the first pulse discharge circuit. The power battery, the motor winding connected to at least another phase bridge arm, the upper bridge arm of the at least other phase bridge arm, and the energy storage capacitor are sequentially connected to form the first pulse discharge circuit.

8. The method according to claim 1, characterized in that, Obtaining the current actual current of the power battery includes: Obtain the phase current of each phase winding of the motor; The sum of the phase currents of each phase winding is calculated to obtain the current actual current.

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 charging pile, the third switch module, the energy storage capacitor, the inverter, the motor, the second switch module, and the power battery are connected in sequence. The first switch module is connected between the power battery and the inverter. The motor controller further includes a control circuit, which is used for: The system receives a pulse heating command, which instructs the battery heating system to use a charging pile pulse heating mode to pulse heat the power battery. The charging pile pulse heating mode refers to controlling the charging pile, the power battery, and the energy storage capacitor to cycle through charging and discharging to heat the power battery. In response to the pulse heating command, the system obtains the current running time within the current pulse cycle for pulse heating of the power battery and the current actual current of the power battery, and determines the current target current based on the current running time. The duty cycle of the inverter is obtained based on the current target current and the current actual current, and the switching on and off of each phase bridge arm in the inverter is controlled based on the duty cycle to pulse heat the power battery.

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

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