Traction battery charging apparatus and pulse charging method

Abstract

Disclosed in the present application are a traction battery charging apparatus and a pulse charging method, which are used for reusing a circuit structure of an existing electric-motor controller inside a vehicle. The traction battery charging apparatus comprises four main connection ports, wherein two connection ports are configured to connect to positive and negative terminals of a charging pile, and the other two connection ports are configured to connect to positive and negative terminals of a traction battery. A power circuit in an electric-motor controller is used to convert, into a pulse current, electric energy output by a direct-current charging pile, thereby realizing the efficient pulse charging of a traction battery while reducing the hardware investment cost, and thus effectively prolonging the service life of the traction battery.

Description

A power battery charging device and pulse charging method Technical Field

[0001] This application relates to the field of charging, and in particular to a power battery charging device and a pulse charging method. Background Technology

[0002] Traditional constant current (CC) charging is widely used in the charging field. Although the charging process using CC charging is relatively stable and easy to control, prolonged constant current charging can cause polarization inside the battery, thereby accelerating battery aging and capacity degradation.

[0003] With the increasing demand for electric vehicles, energy storage systems, and other high-energy-density applications, improving battery performance and extending battery life have become critical issues. In response, pulse charging is increasingly being applied in practical scenarios. Pulse charging combines periodic applications of high-current pulses with short pauses. Each pulse cycle includes a fast-charging phase and a recovery phase, where the recovery phase helps alleviate internal battery stress, promotes ion diffusion, and reduces polarization effects. Compared to CC charging, pulse charging can significantly reduce battery life degradation at the same average charging rate.

[0004] However, to achieve pulse charging, additional circuitry, such as boost or buck converters, is typically required between the power supply and the battery. These circuits provide high-frequency load regulation to control the pulse current. Adding these circuits requires additional hardware investment, increasing costs, and the added circuitry not only adds weight but also occupies space within the vehicle.

[0005] In view of this, in order to achieve efficient pulse charging while reducing hardware investment, minimizing in-vehicle space occupation, simplifying system complexity, and reducing failure risk, a new power battery charging device needs to be designed. Summary of the Invention

[0006] This application provides a power battery charging device and a pulse charging method, which reuses the circuit structure of the existing motor controller in the vehicle to convert the electrical energy output from the DC charging pile into pulse current, thereby reducing hardware investment costs while achieving efficient pulse charging of the power battery, thus effectively improving the life of the power battery.

[0007] Firstly, this application provides a power battery charging device with four main connection points: two for connecting to the positive and negative terminals of a charging station, and the other two for connecting to the positive and negative terminals of the power battery. The device reuses a motor controller, a power circuit that converts electrical energy, and a bus capacitor. The two ends of the capacitor are connected to the positive and negative terminals of the charging station, respectively, while the controller is connected to the battery in a specific manner to receive direct current from the charging station and convert it into a pulse current suitable for charging the battery.

[0008] Through the above design, the power battery charging device of this application can achieve pulse charging of electric vehicle power batteries while ensuring safety and reliability. Simultaneously, by reusing the circuit structure of the existing motor controller in the vehicle, the electrical energy output from the DC charging pile is converted into pulse current, thereby reducing hardware investment costs while achieving efficient pulse charging of the power battery, thus effectively improving the battery's lifespan.

[0009] As one possible implementation, the charging process of the DC charging pile for the power battery includes a first cycle and a second cycle. In the first cycle, the motor controller receives the DC power output from the DC charging pile and performs power conversion on the DC power to charge the power battery with a current of a set amplitude. In the second cycle, the current amplitude output by the motor controller is zero.

[0010] The charging process is divided into two stages: In the first cycle, the motor controller converts the DC power provided by the charging pile to charge the battery with a set current intensity. In the second cycle, the motor controller stops outputting current. During this stage, the power battery has time to depolarize in order to avoid lithium plating on the negative electrode of the battery, thereby extending the life of the power battery.

[0011] In one possible implementation, the device further includes a controller that, in a first sub-interval of the first cycle, controls the switching transistor of the upper arm of at least one of the three-phase bridge arms to be turned on and controls the switching transistor of the lower arm of at least one of the three-phase bridge arms to be turned off; and in a second sub-interval of the first cycle, controls the switching transistor of the lower arm of at least one of the three-phase bridge arms to be turned on and controls the switching transistor of the upper arm of at least one of the three-phase bridge arms to be turned off.

[0012] In the first sub-interval, the controller turns on the upper arm switch of at least one three-phase bridge arm while simultaneously turning off the lower arm switch of that arm. At this time, the bridge arm can be considered a buck converter, outputting a current of a set amplitude. In the second sub-interval, the controller turns on the lower arm switch of at least one three-phase bridge arm while simultaneously turning off the upper arm switch of that arm. This arm stops outputting current, thereby achieving pulse charging of the power battery.

[0013] In one possible implementation, the controller is used to acquire the output voltage of the DC charging pile and the rated voltage of the power battery, and determine the duration of the first sub-interval and the second sub-interval based on the output voltage of the DC charging pile and the rated voltage of the power battery.

[0014] By dynamically adjusting the duration of the first and second sub-intervals, the controller can optimize charging efficiency, protect the battery, extend its lifespan, and ensure charging safety.

[0015] In one possible implementation, the controller is used to: during the second cycle, control the individual switches in the three-phase bridge arm to disconnect. After the individual switches in the three-phase bridge arm are disconnected, the power battery undergoes depolarization to prevent lithium plating on the negative electrode, thereby extending the battery's lifespan.

[0016] In one possible implementation, the controller is used to: acquire the voltage of the power battery during the first cycle, and determine whether to switch to execute the action of the second cycle based on the voltage of the power battery and a first set voltage threshold.

[0017] In the first cycle, the motor controller receives DC power from the DC charging pile and converts it into power to charge the power battery with a current of a set amplitude. The power battery voltage gradually rises, and the power battery is charging and polarizing. When the battery voltage reaches or exceeds the first set threshold, it is considered that the battery has completed a certain degree of polarization and needs to enter the depolarization stage, that is, to execute the second cycle.

[0018] In one possible implementation, the controller is used to: acquire the voltage of the power battery during the second cycle; and, based on the power battery voltage and a second set voltage threshold, determine whether to switch to execute the actions of the first cycle, thereby completing depolarization and extending the life of the power battery.

[0019] During the second cycle, the current amplitude output by the motor controller is zero, which means that charging to the power battery stops. The power battery voltage gradually decreases, indicating that the power battery is undergoing depolarization. When the battery voltage is lower than the second set threshold, it indicates that the battery has completed depolarization and can re-enter the charging cycle, that is, execute the first cycle to improve charging efficiency.

[0020] As one possible implementation, during the charging process of the DC charging pile for the power battery, the in-vehicle load is connected to both ends of the power battery and is in a state of power consumption.

[0021] During pulse charging of electric vehicles, negative pulses can be achieved by making reasonable use of the vehicle's load, further reducing the polarization of the power battery. This not only helps improve charging efficiency but also extends battery life.

[0022] As one possible implementation, during the second cycle, the power battery is used to power the loads inside the vehicle.

[0023] In this way, the high-voltage load inside the vehicle can be effectively used to assist the battery depolarization process without significantly increasing the overall vehicle energy consumption, thereby improving charging efficiency and battery life.

[0024] In one possible implementation, the device also includes at least one control switch, which corresponds to at least one in-vehicle load. The in-vehicle load is connected to both ends of the power battery through the corresponding control switch. During the second cycle, the controller is used to control the at least one control switch to be turned on.

[0025] The controller switches on and off the load inside the vehicle according to a set frequency and duty cycle via a control switch. The switching on and off operations of the control switch should be synchronized with the second cycle to ensure that a negative pulse is generated during the charging / stop cycle, thereby reducing communication delay, improving response speed, and ensuring accurate operation.

[0026] In one possible implementation, when the motor controller controls the motor to drive the wheels, one end of the bus capacitor is disconnected from the DC positive port, and the other end of the bus capacitor is disconnected from the DC negative port. The high potential end of each phase arm of the power circuit is connected to the positive port of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative port of the power battery. The motor controller receives the DC power output from the power battery and controls the motor to drive the wheels.

[0027] In the power circuit, the high-side switch of each arm is connected to the positive terminal of the power battery, and the low-side switch is connected to the negative terminal. This allows the DC power to be converted to AC power via these switches when the motor controller sends a control signal, providing power to the motor. The motor controller, based on the vehicle's needs (such as acceleration or deceleration), adjusts the current and voltage output to the motor by controlling the switches in the power circuit, thereby driving the motor to rotate and ultimately driving the wheels.

[0028] As one possible implementation, when the motor controller determines that the output of the DC charging pile is pulsed DC, one end of the bus capacitor is connected to the positive DC port, and the other end of the bus capacitor is connected to the negative DC port. The high potential end of each phase arm of the power circuit is connected to the positive port of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative port of the power battery. The DC charging pile performs pulse charging for the power battery.

[0029] When the charging station itself has a pulse charging function, the vehicle does not need to process the output of the charging station through the power circuit in the motor controller, but can directly use the pulse current provided by the charging station to charge the power battery.

[0030] In one possible implementation, the device further includes a first charging pile switch, a second charging pile switch, a first battery switch, a second battery switch, and a third battery switch. One end of the bus capacitor is used to connect to the DC positive port through the first charging pile switch, and the other end of the bus capacitor is used to connect to the DC negative port through the second charging pile switch. The center tap of the three-phase winding is also used to connect to the positive port of the power battery through the first battery switch. The high potential end of each phase bridge arm of the power circuit is used to connect to the positive port of the power battery through the second battery switch, and the low potential end of each phase bridge arm of the power circuit is used to connect to the negative port of the power battery through the third battery switch.

[0031] By combining multiple switches, various operating modes can be switched, including normal charging, pulse charging, and motor drive. Safe switching between different modes avoids unnecessary electrical connections, reducing the risk of malfunction. In pulse charging mode, the pulse current provided by the charging station can be directly utilized, improving charging efficiency.

[0032] In one possible implementation, the device also includes a controller. During the process of the DC charging pile charging the power battery, the controller controls the first charging pile switch, the second charging pile switch, the first battery switch, and the third battery switch to be turned on, and the second battery switch to be turned off. When the motor controller controls the motor to drive the wheels, the controller controls the second battery switch and the third battery switch to be turned on, and the first charging pile switch, the second charging pile switch, and the first battery switch to be turned off. When the motor controller determines that the output of the DC charging pile is pulsed DC power, the first charging pile switch, the second charging pile switch, the second battery switch, and the third battery switch are turned on, and the first battery switch is turned off.

[0033] In one possible implementation, the DC charging pile charging process for the power battery includes a first cycle and a second cycle. The device also includes a controller. The first cycle includes a first interval, a second interval, and a third interval. The controller is used to: in the first sub-interval of the first interval, control the switching transistor of the upper arm of the first bridge arm of the three-phase bridge arm to be turned on and control the switching transistor of the lower arm of the first bridge arm of the three-phase bridge arm to be turned off; in the second sub-interval of the first interval, control the switching transistor of the lower arm of the first bridge arm of the three-phase bridge arm to be turned on and control the switching transistor of the upper arm of the first bridge arm of the three-phase bridge arm to be turned off; in the first sub-interval of the second interval, control the switching transistor of the upper arm of the second bridge arm of the three-phase bridge arm to be turned on and control the switching transistor of the lower arm of the second bridge arm of the three-phase bridge arm to be turned off. In the second sub-interval of the second interval, the switch transistor controlling the lower arm of the second bridge arm of the three-phase bridge arm is turned on, and the switch transistor controlling the upper arm of the second bridge arm of the three-phase bridge arm is turned off. In the first sub-interval of the third interval, the switch transistor controlling the upper arm of the third bridge arm of the three-phase bridge arm is turned on, and the switch transistor controlling the lower arm of the third bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the third interval, the switch transistor controlling the lower arm of the third bridge arm of the three-phase bridge arm is turned on, and the switch transistor controlling the upper arm of the third bridge arm of the three-phase bridge arm is turned off. The time interval between the start time of the first interval and the start time of the second interval is set, and the time interval between the start time of the second interval and the start time of the third interval is set. During the second cycle, the current amplitude output by the motor controller is zero.

[0034] The three-phase bridge arms employ interleaved parallel control. By interleaving the bridge arm control, the current ripples are staggered, thereby reducing the overall current ripple. Since the current ripples of each phase are generated based on their respective PWM signals, there is a phase difference between them. When these current ripples with phase differences are superimposed, some parts can cancel each other out, thus reducing the total output current ripple amplitude.

[0035] Secondly, this application discloses a pulse charging method applied to an electric vehicle. The motor controller in the electric vehicle includes a power circuit and a bus capacitor. The midpoints of the three-phase bridge arms of the power circuit are respectively used to connect the three-phase windings of the motor. The two ends of each phase bridge arm of the power circuit are respectively connected to the two ends of the bus capacitor. The method includes: during the process of charging the power battery using a DC charging pile, controlling one end of the bus capacitor to connect to the positive terminal of the DC charging pile output terminal, and the other end of the bus capacitor to connect to the negative terminal of the DC charging pile output terminal. The center tap of the three-phase windings is connected to the positive terminal of the power battery. The low potential end of each phase bridge arm of the power circuit is connected to the negative terminal of the power battery. The motor controller receives the DC power output from the DC charging pile and performs power conversion on the DC power to pulse charge the power battery.

[0036] Thirdly, this application provides an electric vehicle, including a power battery charging device as described in the first aspect.

[0037] Fourthly, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed by a computer, cause any of the methods described in the second aspect to be implemented.

[0038] Fifthly, this application provides a computer program product, which includes a computer program or instructions that, when executed on a computer, cause any of the methods described in the second aspect to be implemented.

[0039] In a sixth aspect, this application provides a chip including a processor coupled to a memory, the processor being configured to execute a computer program or instructions stored in the memory to enable any of the methods described in the second aspect to be implemented.

[0040] For details of the beneficial effects of aspects two through six above, please refer to the technical effects that can be achieved by the corresponding design in aspect one above, which will not be repeated here. Attached Figure Description

[0041] Figure 1 illustrates an exemplary charging scenario for an electric vehicle according to an embodiment of this application;

[0042] Figure 2 is a schematic diagram of a power battery charging device.

[0043] Figure 3 is a schematic diagram of the pulse current input to the power battery;

[0044] Figure 4 is a schematic diagram of a power battery charging device.

[0045] Figure 5 is a schematic diagram of a power circuit control logic;

[0046] Figure 6 is a schematic diagram of the voltage and pulse current changes of a power battery.

[0047] Figure 7 is a schematic diagram of a power battery charging device.

[0048] Figure 8 is a schematic diagram of a power battery charging device.

[0049] Figure 9 is a schematic diagram of a power battery charging device.

[0050] Figure 10 is a schematic diagram of a power battery charging device.

[0051] Figure 11 is a schematic diagram of a chip structure. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, a further detailed description of this application will be provided below in conjunction with the accompanying drawings. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction described in this application are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this application. The accompanying drawings of this application are for illustrating relative positional relationships only and do not represent actual scale.

[0053] It should be noted that in the embodiments of this application, "connection" refers to electrical connection. The connection between two electrical devices can be a direct or indirect connection between the two electrical devices. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical devices, such as the connection between A and B. Alternatively, it can be a direct connection between A and C, with C directly connected to B, and A and B connected through C.

[0054] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0055] The following provides explanations for some of the terms used in this application. It should be noted that these explanations are for the convenience of those skilled in the art and do not constitute a limitation on the scope of protection claimed in this application.

[0056] I. Polarization Phenomenon

[0057] Polarization refers to the phenomenon during battery charging and discharging where various internal and external factors cause uneven electrochemical reactions within the battery, leading to a decline in battery performance. Polarization mainly includes the following types:

[0058] Ohmic polarization: Voltage drop caused by the internal resistance of a battery. Ohmic polarization is usually related to the internal structure and material properties of the battery and is irreversible.

[0059] Concentration polarization: a voltage drop caused by uneven ion concentration distribution in the electrolyte. Concentration polarization typically occurs during high-rate charge and discharge processes and is reversible.

[0060] Electrochemical polarization: The voltage drop caused by inconsistent reaction rates on the electrode surface. Electrochemical polarization is related to factors such as electrode materials, electrolyte properties, and temperature, and is reversible.

[0061] II. Depolarization

[0062] Depolarization refers to the process of restoring the uneven electrochemical reaction state caused by polarization within a battery to normal during charging and discharging by taking certain measures. The main purpose of depolarization is to reduce or eliminate polarization effects, restore battery performance, and extend battery life.

[0063] The preceding text introduced some of the terms used in this application. The following text introduces the possible application scenarios of this application.

[0064] Electric vehicles, also known as new energy vehicles, are automobiles powered by electricity. With the rapid development of electric vehicles, charging technology has become increasingly important. Please refer to Figure 1, which illustrates a charging scenario for an electric vehicle according to an embodiment of this application. As shown in Figure 1, the electric vehicle 10 mainly includes a power battery 12, a control unit 111, a motor control unit (MCU) 112, a motor 113, and wheels 14. The power battery 12 is a high-capacity, high-power storage battery. When the electric vehicle 10 is in motion, the power battery 12 can supply power to the motor 113 through the control unit 111 and the MCU 112. The motor 113 converts the electrical energy provided by the power battery 12 into mechanical energy, thereby driving the wheels 14 to rotate, thus enabling the vehicle to move.

[0065] Referring to Figure 1, when charging electric vehicle 10, it can generally be charged through charging station 20. This charging station 20 mainly includes a power circuit 21 and a charging gun 22. One end of the power circuit 21 is connected to the power grid 30, and the other end is connected to the charging gun 22 via a cable. Currently, there are two charging methods for electric vehicles: AC charging and DC charging. AC charging uses 220V AC power and is slower, typically requiring 6-8 hours to fully charge. DC charging uses a higher voltage, reaching 500-800V, and typically takes 0.5-1 hour to fully charge. Therefore, to improve the charging speed of electric vehicles, most charging stations 20 at present are DC charging stations. When charging is required, the operator can insert the charging gun 22 into the charging port 15 of the electric vehicle 10 to connect the charging gun 22 with the power battery 12 inside the electric vehicle 10. At this time, the power circuit 21 in the charging pile 20 can convert the AC power provided by the power frequency grid 30 into DC power, and then output the DC power to the power battery 12 through the charging gun 22 so that the power battery 12 can use the output voltage of the charging pile 20 to complete the charging.

[0066] In a DC fast charging scenario, the output voltage of the charging pile 20 can be understood as the power supply voltage received by the electric vehicle 10, which is within the charging voltage range of the power battery 12. The lower limit of the charging voltage range of the power battery 12 is the minimum charging voltage, which can be understood as the minimum charging voltage that the power battery 12 can adapt to. The upper limit of the charging voltage range of the power battery 12 is the maximum charging voltage, which can be understood as the maximum charging voltage that the power battery 12 can adapt to.

[0067] For example, the electric vehicle 10 mentioned above can be various types of vehicles, such as including but not limited to pure electric vehicles (pure electric vehicle / battery electric vehicle, pure EV / battery EV), hybrid electric vehicles (HEV), range-extended electric vehicles (REEV), plug-in hybrid electric vehicles (PHEV), other new energy vehicles (NEV), or fuel vehicles, etc. These vehicles can be applied to fields such as intelligent driving, assisted driving, or connected vehicles.

[0068] When charging electric vehicle 10, it can generally be charged through charging pile 20. As shown in Figure 1, charging pile 20 mainly includes power circuit 21 and charging gun 22. One end of power circuit 21 is connected to the power grid 30, and the other end is connected to charging gun 22 via a cable. Currently, most charging piles 20 are DC charging piles, and power circuit 21 can convert the AC power provided by power grid 30 into DC power. The operator can insert charging gun 22 into the charging port of electric vehicle 10, so that charging gun 22 is connected to the power battery 12 in electric vehicle 10, and power circuit 21 of charging pile 20 can then charge power battery 12 through charging gun 22.

[0069] The output voltage of the charging pile 20 can be understood as the charging voltage received by the power battery 12 of the electric vehicle 10. In the DC fast charging scenario, the charging voltage received by the power battery 12 is within the charging voltage range of the power battery 12.

[0070] With the increasing demand from electric vehicles, energy storage systems, and other high-energy-density applications, improving battery performance and extending battery life has become a key focus for the industry. Traditionally, constant-current charging has been widely adopted due to its stable process and ease of control. However, prolonged use of constant-current charging (CC charging) can exacerbate internal battery polarization, thereby accelerating battery aging and capacity degradation.

[0071] To address the aforementioned issues, pulse charging has emerged as a new charging technology. Pulse charging combines periodic applications of high-current pulses with brief pauses. Each pulse cycle includes a fast charging phase and a recovery phase. During the recovery phase, internal battery stress is reduced, ion diffusion is promoted, and polarization effects are reduced. Compared to traditional CC charging, pulse charging can significantly reduce battery lifespan degradation and improve overall battery performance while maintaining the same average charging rate.

[0072] Experimental data shows that pulse charging has a significant advantage in improving battery life. Taking 1000 charge-discharge cycles as an example, the state of health (SOH) varies significantly under different charging conditions. Under 1C constant current charging, the SOH decreases by 62.2%, while under 100Hz pulse charging (2C / 0C), the SOH decreases by 33.52%. If the pulse frequency is further increased to 2000Hz, the SOH decrease is only 18.27%. Pulse charging helps to significantly improve battery capacity retention, thereby extending battery life.

[0073] It should be understood that the pulse charging provided in this application can also be applied to other possible scenarios, and is not limited to those exemplified above. For example, pulse charging can also be applied to other types of electric vehicles, such as ships, airplanes, drones, trains, subways, high-speed trains, or transport vehicles, to improve the charging efficiency and lifespan of the power batteries in these vehicles. Furthermore, this method is equally applicable to electric vehicles of all sizes, from micro electric vehicles to large commercial electric trucks.

[0074] It should be noted that the application scenarios described in this application are for the purpose of more clearly illustrating the technical solutions of this application, and do not constitute a limitation on the technical solutions provided in this application.

[0075] As described in the background section, implementing pulse charging requires additional circuitry to provide pulse regulation, such as boost or buck circuits. This not only increases system cost but also introduces additional space requirements.

[0076] In view of this, this application provides a new power battery charging device that reduces hardware investment, reduces in-vehicle space occupation, simplifies system complexity and reduces failure risk, while achieving efficient pulse charging.

[0077] Referring to Figure 2, which is a schematic diagram of a power battery charging device, the power battery charging device includes a DC positive port 201, a DC negative port 202, a power battery positive port 203, a power battery negative port 204, and a motor controller 205. The DC positive port 201 is used to connect to the positive terminal of the DC charging pile 206 output terminal, the DC negative port 202 is used to connect to the negative terminal of the DC charging pile 206 output terminal, the power battery positive port 203 is used to connect to the positive terminal of the power battery 207, and the power battery negative port 204 is used to connect to the negative terminal of the power battery 207.

[0078] The motor controller 205 includes a power circuit 2051 and a bus capacitor 2052. The midpoints of the three-phase bridge arms of the power circuit are used to connect to the three-phase windings of the motor 208. The two ends of each phase bridge arm of the power circuit are connected to the two ends of the bus capacitor. One end of the bus capacitor is used to connect to the DC positive port 201, and the other end is used to connect to the DC negative port 202. The center tap of the three-phase windings is also used to connect to the positive port 203 of the power battery. The low potential end of each phase bridge arm of the power circuit is used to connect to the negative port 204 of the power battery. The motor controller 205 receives the DC power output from the DC charging pile 206 and performs power conversion on the DC power to provide pulse charging for the power battery 207.

[0079] Motor 208 can be a hub motor or a wheel-side motor. The vehicle has a motor on at least one axle, and this motor is connected to a wheel on that axle. This at least one axle can be a drive axle, a driven axle, or both. When the at least one axle is only a drive axle or only a driven axle, the wheels on the other axle can be connected by a mechanical structure, such as the rear-wheel steering mechanism in a main rear-wheel steering system, or other mechanical structures, without limitation. When the at least one axle includes both a drive axle and a driven axle, it can be equipped with only one motor, which is simultaneously connected to four wheels on two drive axles. Alternatively, one motor can be installed on each drive axle, and each motor on each drive axle can be connected to two wheels on that drive axle. Alternatively, two motors can be installed on each drive axle, and each motor can be connected to one wheel. Alternatively, one motor can be installed on one drive axle, and two motors can be installed on the other drive axle, and so on.

[0080] Specifically, when the DC positive port 201 and DC negative port 202 of the electric vehicle are connected to the DC charging pile 206, the output voltage of the DC charging pile 206 first reaches the motor controller 205 (i.e. the two ends of the bus capacitor) through the DC positive port 201 and DC negative port 202. After reaching the motor controller 205, it controls the conduction and cutoff of each switching device in the power circuit, and directly supplies the output voltage of the DC charging pile 206 to the power battery 207 through the winding of the motor 208, so as to realize the pulse charging of the power battery 207.

[0081] The power circuit can adopt a three-phase bridge arm structure, with each bridge arm (i.e., U, V, and W phases) containing two switching devices (upper bridge arm and lower bridge arm), forming a complete three-phase inverter. The midpoint of each bridge arm is directly connected to the corresponding three-phase winding of the motor, thereby enabling the regulation of the voltage and current applied to the motor by controlling the state of these switching devices.

[0082] The bus capacitor is located at both ends of the power circuit, with one end connected to the DC positive port 201 and the other end connected to the DC negative port 202. The function of the bus capacitor is to stabilize the voltage on the DC side and absorb instantaneous power fluctuations from the power supply or load.

[0083] Referring again to Figure 2, the power circuit includes three bridge arms, which can be denoted as the U-phase bridge arm, V-phase bridge arm, and W-phase bridge arm. The motor includes three motor windings corresponding to the three bridge arms (e.g., motor winding U, motor winding V, and motor winding W). In the U-phase bridge arm, the upper bridge switch is switch Q1, and the lower bridge switch is switch Q2. In the V-phase bridge arm, the upper bridge switch is switch Q3, and the lower bridge switch is switch Q4. In the W-phase bridge arm, the upper bridge switch is switch Q5, and the lower bridge switch is switch Q6. The collectors of switches Q1, Q3, and Q5 are connected to one end of the bus capacitor, and the emitters of switches Q2, Q4, and Q6 are connected to the other end of the bus capacitor. The emitter of transistor Q1 and the collector of transistor Q2 are connected to one end of motor winding U. The emitter of transistor Q3 and the collector of transistor Q4 are connected to one end of motor winding V. The emitter of transistor Q5 and the collector of transistor Q6 are connected to one end of motor winding W. The other ends of motor winding U, motor winding V, and motor winding W can be called the center tap of the motor.

[0084] The switching transistors in the aforementioned bridge arms can be insulated-gate bipolar transistors (IGBTs) and their anti-parallel diodes, or metal-oxide-semiconductor field-effect transistors (MOSFETs), etc. This application does not impose excessive restrictions on the specific internal structure of the switching transistors.

[0085] The drive motor can also be a two-phase AC motor, a four-phase AC motor, or a five-phase AC motor. In this case, the power circuit adapts the number of bridge arms according to the number of windings of different types of motors. For example, when the drive motor is a two-phase AC motor, the power circuit includes two-phase bridge arms; when the drive motor is a four-phase AC motor, the power circuit includes four-phase bridge arms.

[0086] The DC power provided by the DC charging pile 206 is connected to the motor controller 205 through the DC positive port 201 and the DC negative port 202. The center tap of the three-phase winding (i.e. the common point of the three-phase winding) is connected to the positive port 203 of the power battery, and the low potential end of each phase bridge arm of the power circuit is connected to the negative port 204 of the power battery. Current can flow out or into the power battery 207 effectively.

[0087] After receiving DC power from DC charging pile 206, motor controller 205 controls the switching devices in the power circuit to convert DC power into pulse current with specific frequency and amplitude, thereby providing efficient and controllable charging service for power battery 207. The pulse charging of power battery 207 achieved by the above connection method not only helps to improve the charging efficiency of power battery 207, but also effectively reduces the problem of reduced lifespan of power battery 207 caused by continuous high current charging.

[0088] Furthermore, by utilizing the existing structure of the in-vehicle motor controller 205, there is no need to add a dedicated charging circuit, thereby reducing hardware costs and complexity. Since the power circuit in the motor controller 205 has switching devices, pulse charging can be directly achieved using the power circuit and bus capacitor in the motor controller 205, reducing the need for additional circuit design.

[0089] Through the above design, the power battery charging device of this application can perform pulse charging of the electric vehicle power battery 207 while ensuring safety and reliability. At the same time, by reusing the circuit structure of the existing motor controller 205 in the vehicle, the electrical energy output from the DC charging pile 206 is converted into pulse current, thereby reducing hardware investment costs.

[0090] In order to specifically realize pulse charging of the electric vehicle power battery 207, as one possible implementation, the DC charging pile 206 can charge the power battery 207 in a process that includes multiple cycles. For example, the multiple cycles may specifically include a first cycle and a second cycle.

[0091] During the first cycle, the motor controller 205 receives the DC power output from the DC charging pile 206 and performs power conversion on the DC power to charge the power battery 207 with a current of a set amplitude.

[0092] During the second cycle, the current amplitude output by the motor controller 205 is zero.

[0093] Figure 3 is a schematic diagram of the pulse current input to the power battery. In the first cycle, the current input to the power battery 207 is a positive pulse, and in the second cycle, the current input to the power battery 207 is a zero pulse. A positive pulse is a pulse with a pulse amplitude set to a threshold value (e.g., 0), and a zero pulse is a pulse with a pulse waveform that is the set threshold value (e.g., 0).

[0094] The waveform of the pulse current can be, but is not limited to, sine waves, square waves, pulses, increasing waves, and decreasing waves. The pulse current used in this application is a square wave, and the following embodiments are illustrated using square wave waveforms. The frequency of the pulse current is set according to the specific conditions of the power battery 207. Depending on the usage scenario, the pulse current can be a fixed frequency or it can change dynamically with the SOC. The frequency selection range of the pulse is not limited.

[0095] The motor controller 205 can be understood as a pulse current conversion circuit. Specifically, in the first cycle, the motor controller 205 receives DC power from the DC charging pile 206 and converts it into power to charge the power battery 207 with the converted current of the set amplitude.

[0096] The DC charging pile 206 supplies DC power to the motor controller 205 through the DC positive port 201 and the DC negative port 202. The power circuit in the motor controller 205 converts the DC power into the required pulse current.

[0097] According to the preset current amplitude, the motor controller 205 controls the switching devices (upper bridge arm and lower bridge arm) in the power circuit to turn on and off, generating a pulse current with a set amplitude.

[0098] The generated pulse current is transmitted to the power battery 207 through the center tap of the three-phase winding (connected to the positive port 203 of the power battery) and the low potential end of each phase bridge arm (connected to the negative port 204 of the power battery), thereby charging the power battery 207.

[0099] During the second cycle, the current amplitude output by the motor controller 205 is zero, that is, charging of the power battery 207 stops.

[0100] The motor controller 205 controls all switching devices in the power circuit to be in the off state, so that the output current amplitude is zero.

[0101] During this stage, the power battery 207 has time to depolarize to prevent lithium plating on the negative electrode, thereby extending the lifespan of the power battery 207. After the second cycle ends, it prepares to enter the next first cycle and continue pulse charging.

[0102] The motor controller 205 can automatically switch between the first cycle and the second cycle based on a preset time interval or the state of the power battery 207 (such as voltage, temperature, etc.). Depending on actual needs, the duration of the first and second cycles can be adjusted via a preset program or external commands to adapt to different charging scenarios and battery types.

[0103] Through the above-described embodiments, the power battery charging device of this application can achieve efficient pulse charging while ensuring cost reduction. This charging method not only improves charging efficiency but also extends battery life and reduces maintenance costs.

[0104] Referring to Figure 4, which is a schematic diagram of the structure of a power battery charging device, as one possible implementation, the device further includes a controller 401. In the first sub-interval of the first cycle, the controller turns on the switch of the upper arm of at least one arm of the three-phase bridge arm and turns off the switch of the lower arm of at least one arm of the three-phase bridge arm. In the second sub-interval of the first cycle, the controller turns on the switch of the lower arm of at least one arm of the three-phase bridge arm and turns off the switch of the upper arm of at least one arm of the three-phase bridge arm.

[0105] Within the first sub-interval, controller 401 controls the upper arm switch of at least one three-phase bridge arm to be turned on, while simultaneously controlling the lower arm switch of that bridge arm to be turned off.

[0106] At this point, the bridge arm can be considered as a buck converter circuit, outputting a current of a set amplitude.

[0107] Within the second sub-interval, controller 401 controls the lower arm switch of at least one three-phase bridge arm to turn on, while simultaneously controlling the upper arm switch of that bridge arm to turn off. At this time, the bridge arm stops outputting current.

[0108] The ratio of the duration of the first sub-interval to the duration of a cycle can be regarded as the first duty cycle of the switch of the upper arm of at least one bridge arm. The ratio of the duration of the second sub-interval to the duration of a cycle can be regarded as the second duty cycle of the switch of the lower arm of at least one bridge arm. The duty cycle is related to the output voltage of the DC charging pile 206 and the rated voltage of the power battery 207. The sum of the first duty cycle and the second duty cycle is 1.

[0109] A higher output voltage from the charging pile requires a lower duty cycle to ensure that the output current does not exceed the set value, while a lower rated voltage from the power battery 207 requires a higher duty cycle to ensure that the charging current reaches the set value. The controller 401 can dynamically adjust the duty cycle according to the output voltage of the DC charging pile 206 and the rated voltage of the power battery 207 to ensure the stability of the charging current.

[0110] In one possible implementation, the controller 401 is used to acquire the output voltage of the DC charging pile 206 and the rated voltage of the power battery 207, and determine the duration of the first sub-interval and the second sub-interval based on the output voltage of the DC charging pile 206 and the rated voltage of the power battery 207.

[0111] Assuming the output voltage (voltage input to the power circuit) of the DC charging pile 206 is Vin, the rated voltage (voltage output by the power circuit) of the power battery 207 is Vout, and the duty cycle of the switch of the upper arm of at least one bridge arm is D, therefore, Vout = Vin * D.

[0112] To reduce the overall current ripple of the three-phase bridge arms, interleaved parallel control can be adopted. By interleaving the control voltage of the bridge arms, the current ripple is also interleaved, thereby reducing the overall current ripple. As one possible implementation, the first cycle includes a first interval, a second interval, and a third interval.

[0113] Controller 401 is used to control the switching transistor of the upper arm of the first bridge arm of the three-phase bridge arm to be turned on and the switching transistor of the lower arm of the first bridge arm of the three-phase bridge arm to be turned off in the first sub-interval of the first interval; and to control the switching transistor of the lower arm of the first bridge arm of the three-phase bridge arm to be turned on and the switching transistor of the upper arm of the first bridge arm of the three-phase bridge arm to be turned off in the second sub-interval of the first interval. Similarly, to control the switching transistor of the upper arm of the second bridge arm of the three-phase bridge arm to be turned on and the switching transistor of the lower arm of the second bridge arm of the three-phase bridge arm to be turned off in the first sub-interval of the second interval; and to control the switching transistor of the lower arm of the second bridge arm of the three-phase bridge arm to be turned on and the switching transistor of the upper arm of the second bridge arm of the three-phase bridge arm to be turned off in the second sub-interval of the second interval. Within the first sub-interval of the third interval, the switch controlling the upper arm of the third bridge arm of the three-phase bridge arm is turned on, and the switch controlling the lower arm of the third bridge arm of the three-phase bridge arm is turned off. Within the second sub-interval of the third interval, the switch controlling the lower arm of the third bridge arm of the three-phase bridge arm is turned on, and the switch controlling the upper arm of the third bridge arm of the three-phase bridge arm is turned off. The time interval between the start time of the first interval and the start time of the second interval is set, and the time interval between the start time of the second interval and the start time of the third interval is also set.

[0114] In traditional three-phase bridge arm circuits, periodic current fluctuations, or current ripples, are generated when the switching transistors are turned on and off at a certain frequency. The presence of this ripple increases electromagnetic interference (EMI) and may adversely affect loads such as batteries, such as shortening their lifespan and increasing losses.

[0115] When the three-phase arms of the UVW bridge are controlled by interleaved parallel operation, the PWM signals of each phase do not occur simultaneously, but rather there is a certain phase difference between them. For example, if phase U starts to conduct, phases V and W will start to conduct only after a certain angle.

[0116] Since the current ripple of each phase is generated based on its own PWM signal, there is a phase difference between them. When these current ripples with phase differences are superimposed, some of them can cancel each other out, thereby reducing the total output current ripple amplitude.

[0117] Specifically, in the first cycle, the controller 401 divides the time into three intervals (first, second and third intervals), and each interval is further divided into two sub-intervals.

[0118] The operating mode of each zone is to alternately turn on the corresponding upper or lower bridge arm switches, thereby forming a pulse width modulation (PWM) mode.

[0119] Taking the first interval as an example, in the first sub-interval of the first interval, only the upper arm of the U-phase bridge arm is conducting. In the second sub-interval of the same interval, the lower arm of the U-phase bridge arm is conducting. A similar operating mode is used for the V and W phases, but their start times are staggered by a certain set time.

[0120] Referring to Figure 5, which is a schematic diagram of a power circuit control logic, the three signals in Figure 5 correspond to the PWM control signals of the three-phase bridge arms (U, V, W). Each signal is a square wave, representing the on and off states of the switching transistors. A high level indicates that the corresponding switching transistor is on, and a low level indicates that the corresponding switching transistor is off. The signal in the first sub-interval is the reference signal. The signal in the second sub-interval lags behind the signal in the first sub-interval by a certain time, and the signal in the third sub-interval lags behind the signal in the second sub-interval by the same time again.

[0121] For example, in a three-phase bridge arm circuit, the switching frequency of each phase is f, and the phase difference between phases is 120 degrees. When the upper bridge arm of phase U is turned on, phases V and W have not yet reached their corresponding turn-on times. At this time, the current ripple generated by phase U begins to rise. As phase V begins to conduct, its current ripple also joins in. However, due to the phase difference with phase U, the ripples of the two phases do not completely overlap but partially cancel each other out. Finally, when phase W also starts to work, the combined effect of the three phases further reduces the total current ripple.

[0122] Therefore, by arranging the phase appropriately, the overall output current can be smoothed out, increasing current continuity. This not only reduces ripple but also helps improve system efficiency and stability.

[0123] As one possible implementation, during the first cycle, the voltage of the power battery 207 is acquired, and based on the voltage of the power battery 207 and a first set voltage threshold, it is determined whether to switch to execute the action of the second cycle.

[0124] During pulse charging, the determination of polarization and depolarization states is particularly important. By alternating between charging cycles (first cycle) and stopping cycles (second cycle), the polarization state of the battery can be effectively managed, improving charging efficiency and extending battery life.

[0125] During the first cycle, the controller 401 monitors the voltage of the power battery 207 in real time, compares the voltage of the power battery 207 with the first set voltage threshold, and determines whether the power battery 207 needs to be depolarized. If the voltage of the power battery 207 is greater than the first set voltage threshold, the controller 401 switches to execute the action of the second cycle to achieve depolarization.

[0126] In one possible implementation, during the second cycle, the voltage of the power battery 207 is acquired, and based on the voltage of the power battery 207 and a second set voltage threshold, it is determined whether to switch to execute the action of the first cycle.

[0127] During the second cycle, the controller 401 monitors the voltage of the power battery 207 in real time, compares the voltage of the power battery 207 with the second set voltage threshold, and determines whether the power battery 207 has completed depolarization. If the voltage of the power battery 207 is less than the second set voltage threshold, the controller needs to switch to the action of the first cycle to achieve depolarization. Refer to Figure 6, which is a schematic diagram of power battery voltage and pulse current changes.

[0128] As shown in Figure 6, the power battery 207 is in its initial state with a charging current of 0, indicating that the power battery 207 has not started charging. During the first cycle, the motor controller 205 receives DC power from the DC charging pile 206 and converts it into power to charge the power battery 207 with a current of a set amplitude. The voltage of the power battery 207 gradually increases, indicating that the power battery 207 is charging and polarizing. When the voltage of the power battery 207 reaches or exceeds a first set threshold, it is considered that the battery has completed a certain degree of polarization and needs to enter the depolarization stage, i.e., the second cycle is executed. During the second cycle, the current amplitude output by the motor controller 205 is zero, i.e., charging of the power battery 207 stops, and the voltage of the power battery 207 gradually decreases, indicating that the power battery 207 is undergoing depolarization. When the battery voltage is lower than the second set threshold, it indicates that the battery has completed depolarization and can re-enter the charging cycle, i.e., the first cycle is executed.

[0129] With the pulse charging logic provided in this application, the power battery 207 can be charged and depolarized within an appropriate voltage range, thereby improving charging efficiency and extending battery life.

[0130] Besides battery voltage, other characteristics can be used to determine whether a battery has completed polarization and depolarization, such as state of charge (SOC), battery internal resistance, and the temperature of the power battery 207. In practical applications, multiple parameters can be considered together to determine the polarization and depolarization state of the battery. For example, combining parameters such as battery voltage, internal resistance, and temperature can more accurately determine the battery's state and adjust the charging strategy accordingly; specific limitations are not discussed here.

[0131] As one possible implementation, during the charging process of the DC charging pile 206 for the power battery 207, the in-vehicle load is connected to both ends of the power battery 207 and the in-vehicle load is in a power consumption state.

[0132] During pulse charging of electric vehicles, negative pulses can be achieved by making reasonable use of in-vehicle loads (such as compressors, PTC heaters, air suspension systems, DC-DC converters, etc.), further reducing the polarization phenomenon of the power battery 207. This not only helps improve charging efficiency but also extends battery life.

[0133] Specifically, during the pulse charging process, the high-voltage loads inside the vehicle (such as the compressor, PTC heater, air suspension system, DC-DC converter, etc.) are connected to both ends of the power battery 207. These loads inside the vehicle are in a state of power consumption, that is, the power battery 207 supplies them with power.

[0134] By activating a high-voltage load inside the vehicle, a negative pulse can be generated, further reducing polarization and accelerating the depolarization process. This negative pulse helps reduce electrochemical imbalances within the battery, thereby improving charging efficiency and extending battery life. During charging, making proper use of the vehicle's load can optimize the charging process without adding extra equipment.

[0135] If the vehicle's in-vehicle loads are continuously powered, the overall vehicle energy consumption will increase. Therefore, it is crucial to properly control the operating timing of the in-vehicle loads. As one possible implementation method, during the second cycle, the power battery 207 is used to supply power to the in-vehicle loads.

[0136] During the first cycle, in the normal charging process, the motor controller 205 obtains electrical energy from the DC charging pile 206 to charge the power battery 207.

[0137] During the second cycle, charging is stopped, and in-vehicle loads are activated. These loads consume the energy in the battery, creating negative pulses that promote the depolarization of the power battery 207. In this way, the high-voltage loads inside the vehicle can be effectively used to assist the battery depolarization process without significantly increasing the overall vehicle energy consumption, thereby improving charging efficiency and battery life.

[0138] As one possible implementation, during the charging process of the DC charging pile 206 for the power battery 207, the vehicle load PTC heater is connected to both ends of the power battery 207, and the PTC heater is used to heat the power battery 207.

[0139] In low-temperature environments, the internal materials of the power battery 207 have lower activity. Charging the power battery 207 increases the risk of lithium plating on the negative electrode, which not only affects the performance of the power battery 207 but may also shorten its lifespan. Therefore, under low-temperature conditions, using a PTC (positive temperature coefficient) heater can not only help raise the temperature of the power battery 207 but also serve as a load to assist in the depolarization of the power battery 207.

[0140] Specifically, during charging, the vehicle controller can first detect the temperature of the power battery 207. If the temperature is lower than the set safety threshold (e.g., 0°C), the heating program needs to be started. If the temperature of the power battery 207 is too low, the PTC heater will be activated. The PTC heater starts working, consuming the electrical energy in the power battery 207 and heating the battery at the same time.

[0141] Once the battery temperature reaches a safe range, the normal charging process can begin. During the first cycle, the motor controller 205 draws power from the DC charging station 206 to charge the power battery 207. In the second charging cycle, charging of the power battery 207 stops. At this time, the PTC heater is activated again, drawing power from the power battery 207 to generate a negative pulse, which helps depolarize the power battery 207. In this way, the temperature of the power battery 207 is maintained while promoting battery depolarization.

[0142] Referring to Figure 7, which is a schematic diagram of a power battery charging device, as one possible implementation, the device further includes at least one control switch 701, which corresponds to at least one in-vehicle load 702. The in-vehicle load 702 is connected to both ends of the power battery 207 through the corresponding control switch 701. During the second cycle, the controller 401 controls the at least one control switch 701 to be turned on.

[0143] During the first cycle, the motor controller 205 obtains electrical energy from the DC charging pile 206 to charge the power battery 207.

[0144] During the second cycle, controller 401 controls control switch 701 via hard-wired signals to turn on and off the in-vehicle load 702 according to a set frequency and duty cycle. The on and off operations of control switch 701 should be synchronized with the moment when the charging current is 0 (i.e., synchronized with the second cycle) to ensure the formation of a negative pulse during the off-charging cycle. The operating frequency of control switch 701 should match the moment when the charging current is 0. Using hard-wired signals to control control switch 701 can reduce communication delay and improve response speed. Controller 401 can directly control control switch 701 via hard-wired signals to ensure accurate operation.

[0145] Referring to Figure 8, which is a schematic diagram of a power battery charging device, in one possible implementation, when the motor controller 205 controls the motor to drive the wheels, one end of the bus capacitor is disconnected from the DC positive port 201, and the other end of the bus capacitor is disconnected from the DC negative port 202. The high potential end of each phase arm of the power circuit is connected to the positive port 203 of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative port 204 of the power battery. The motor controller 205 receives the DC power output from the power battery 207 and controls the motor to drive the wheels.

[0146] In electric or hybrid vehicles, the motor controller 205 is responsible for converting the DC power supplied by the power battery 207 into AC power suitable for the motor.

[0147] In the power circuit, the high-side switch of each arm is connected to the positive terminal of the power battery 207, and the low-side switch is connected to the negative terminal of the power battery 207. Thus, when the motor controller 205 sends a control signal, these switches can convert direct current to alternating current for the motor. The motor controller 205, based on the vehicle's needs (such as acceleration or deceleration), adjusts the current and voltage output to the motor by controlling the switches in the power circuit, thereby driving the motor to rotate and ultimately driving the wheels.

[0148] Referring to Figure 9, which is a schematic diagram of a power battery charging device, in one possible implementation where the charging pile itself has a pulse charging function, when the motor controller 205 determines that the output of the DC charging pile 206 is a pulsed DC current, one end of the bus capacitor is connected to the DC positive port 201, and the other end of the bus capacitor is connected to the DC negative port 202. The high potential end of each phase bridge arm of the power circuit is connected to the positive port 203 of the power battery, and the low potential end of each phase bridge arm of the power circuit is connected to the negative port 204 of the power battery. The DC charging pile 206 performs pulse charging for the power battery 207.

[0149] After the charging gun is plugged into the vehicle's charging socket, the vehicle detects the physical connection and wakes up the battery management system. The charging pile provides low-voltage auxiliary power to the vehicle through the control guidance circuit and confirms the connection through the resistance value on the CP line and the PWM signal. Subsequently, the vehicle and the charging pile establish communication through the bus to determine the charging mode supported by the charging pile. When the charging pile supports and selects the pulse charging mode, the vehicle does not need to process the output of the charging pile through the power circuit in the motor controller 205, but can directly use the pulse current provided by the charging pile to charge the power battery 207.

[0150] One end of the bus capacitor is directly connected to the positive output terminal of the DC charging pile 206, and the other end is directly connected to the negative output terminal of the DC charging pile 206. In this way, the bus capacitor smooths voltage fluctuations and ensures voltage stability during charging. The high-potential end of each phase arm is connected to the positive port 203 of the power battery, and one end of the low-side switch of each arm is connected to the negative port 204 of the power battery. The motor controller 205 does not participate in the processing of the charging pile output; instead, it directly transmits the pulse current from the charging pile to the power battery 207.

[0151] Referring to Figure 10, which is a schematic diagram of the structure of a power battery charging device, the device further includes a first charging pile switch 1001, a second charging pile switch 1002, a first battery switch 1003, a second battery switch 1004, and a third battery switch 1005.

[0152] One end of the bus capacitor is used to connect to the DC positive port 201 via the first charging pile switch, and the other end of the bus capacitor is used to connect to the DC negative port 202 via the second charging pile switch. The center tap of the three-phase winding is also used to connect to the positive port 203 of the power battery via the first battery switch. The high potential end of each phase bridge arm of the power circuit is used to connect to the positive port 203 of the power battery via the second battery switch, and the low potential end of each phase bridge arm of the power circuit is used to connect to the negative port 204 of the power battery via the third battery switch.

[0153] The following describes the specific connection relationships of each switch under three different conditions:

[0154] The charging station does not have pulse charging functionality.

[0155] When the first charging pile switch 1001 and the second charging pile switch 1002 are closed, the bus capacitor is connected to the positive and negative ports of the DC charging pile 206 to smooth voltage fluctuations.

[0156] First battery switch 1003 is open: the center tap of the three-phase winding is not connected to the positive terminal 203 of the power battery.

[0157] When the second battery switch 1004 and the third battery switch 1005 are closed, the bridge arm of the power circuit is directly connected to the positive and negative ports of the power battery, and the normal charging process begins.

[0158] The charging station has a pulse charging function:

[0159] When the first charging pile switch 1001 and the second charging pile switch 1002 are closed, the bus capacitor is connected to the positive and negative ports of the DC charging pile 206 to smooth voltage fluctuations.

[0160] First battery switch 1003 is open: the center tap of the three-phase winding is not connected to the positive terminal 203 of the power battery.

[0161] When the second battery switch 1004 and the third battery switch 1005 are closed, the bridge arm of the power circuit is directly connected to the positive and negative ports of the power battery. However, at this time, the motor controller 205 does not participate in the current conversion, and the charging pile directly provides pulse current to the power battery.

[0162] Motor drive mode:

[0163] The first charging pile switch 1001 and the second charging pile switch 1002 are disconnected: the bus capacitor is disconnected from the DC charging pile 206.

[0164] The first battery switch 1003 is closed: the center tap of the three-phase winding is connected to the positive terminal 203 of the power battery.

[0165] When the second battery switch 1004 and the third battery switch 1005 are closed, the bridge arm of the power circuit is directly connected to the positive and negative ports of the power battery, and the motor controller 205 receives the DC power output from the power battery 207 and controls the motor to drive the wheels.

[0166] By combining multiple switches, various operating modes can be switched, including normal charging, pulse charging, and motor drive.

[0167] It allows for safe switching between different modes, avoids unnecessary electrical connections, reduces the risk of malfunctions, and in pulse charging mode, it can directly utilize the pulse current provided by the charging pile to improve charging efficiency.

[0168] Based on the same concept, this application provides a pulse charging method applied to an electric vehicle. The motor controller in the electric vehicle includes a power circuit and a bus capacitor. The midpoints of the three-phase bridge arms of the power circuit are respectively used to connect to the three-phase windings of the motor. The two ends of each phase bridge arm of the power circuit are respectively connected to the two ends of the bus capacitor. The method includes:

[0169] In the process of charging the power battery using a DC charging pile, one end of the control bus capacitor is connected to the positive terminal of the DC charging pile output, and the other end of the bus capacitor is connected to the negative terminal of the DC charging pile output. The center tap of the three-phase winding is connected to the positive terminal of the power battery, and the low potential end of each phase bridge arm of the power circuit is connected to the negative terminal of the power battery. The motor controller receives the DC power output from the DC charging pile and performs power conversion to provide pulse charging for the power battery.

[0170] As one possible implementation, the motor controller receives DC power output from the DC charging pile and performs power conversion on the DC power to provide pulse charging for the power battery, including:

[0171] During the first cycle, the motor controller receives the DC power output from the DC charging pile, performs power conversion on the DC power, and then charges the power battery with a current of a set amplitude.

[0172] During the second cycle, the current amplitude output by the motor controller is zero.

[0173] As one possible implementation, the motor controller receives DC power output from the DC charging pile and performs power conversion on the DC power to provide pulse charging for the power battery, including:

[0174] In the first sub-interval of the first cycle, the switch tube controlling the upper arm of at least one of the three-phase bridge arms is turned on, and the switch tube controlling the lower arm of at least one of the three-phase bridge arms is turned off. In the second sub-interval of the first cycle, the switch tube controlling the lower arm of at least one of the three-phase bridge arms is turned on, and the switch tube controlling the upper arm of at least one of the three-phase bridge arms is turned off.

[0175] As one possible implementation, the method further includes: acquiring the output voltage of the DC charging pile and the rated voltage of the power battery, and determining the duration of the first sub-interval and the second sub-interval based on the output voltage of the DC charging pile and the rated voltage of the power battery.

[0176] As one possible implementation method, the method specifically includes:

[0177] During the second cycle, each switch in the three-phase bridge arm is disconnected.

[0178] As one possible implementation, the method further includes: during the first cycle, acquiring the voltage of the power battery, and determining whether to switch to execute the action of the second cycle based on the voltage of the power battery and a first set voltage threshold.

[0179] As one possible implementation, the method further includes: during the second cycle, acquiring the voltage of the power battery, and determining whether to switch to execute the actions of the first cycle based on the voltage of the power battery and a second set voltage threshold.

[0180] As one possible implementation, the method further includes: during the charging process of the power battery by the DC charging pile, controlling the load inside the vehicle to be connected to both ends of the power battery, and the load inside the vehicle is in a state of power consumption.

[0181] As one possible implementation, the method further includes: during the second cycle, controlling the in-vehicle load to be connected to both ends of the power battery so that the power battery supplies power to the in-vehicle load.

[0182] In one possible implementation, the method further includes: when the motor controller controls the motor to drive the wheels, one end of the control bus capacitor is disconnected from the positive terminal of the DC charging pile, and the other end of the bus capacitor is disconnected from the negative terminal of the DC charging pile. The high potential end of each phase arm of the power circuit is connected to the positive terminal of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative terminal of the power battery. The motor controller receives the DC power output from the power battery and controls the motor to drive the wheels.

[0183] In one possible implementation, the method further includes: when the motor controller determines that the output of the DC charging pile is pulsed DC power, one end of the bus capacitor is connected to the positive terminal of the DC charging pile, and the other end of the bus capacitor is connected to the negative terminal of the DC charging pile. The high potential terminal of each phase arm of the power circuit is connected to the positive terminal of the power battery, and the low potential terminal of each phase arm of the power circuit is connected to the negative terminal of the power battery, so that the DC charging pile performs pulse charging for the power battery.

[0184] As one possible implementation, the motor controller receives DC power output from the DC charging pile and performs power conversion on the DC power to provide pulse charging for the power battery, including:

[0185] The charging process of a DC charging pile for a power battery includes a first cycle and a second cycle. The first cycle includes a first interval, a second interval, and a third interval.

[0186] The method also includes:

[0187] In the first sub-interval of the first interval, the switch tube controlling the upper arm of the first bridge arm of the three-phase bridge arm is turned on, and the switch tube controlling the lower arm of the first bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the first interval, the switch tube controlling the lower arm of the first bridge arm of the three-phase bridge arm is turned on, and the switch tube controlling the upper arm of the first bridge arm of the three-phase bridge arm is turned off.

[0188] In the first sub-interval of the second interval, the switch tube controlling the upper arm of the second bridge arm of the three-phase bridge arm is turned on, and the switch tube controlling the lower arm of the second bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the second interval, the switch tube controlling the lower arm of the second bridge arm of the three-phase bridge arm is turned on, and the switch tube controlling the upper arm of the second bridge arm of the three-phase bridge arm is turned off.

[0189] In the first sub-interval of the third interval, the switch tube controlling the upper bridge arm of the third bridge arm of the three-phase bridge arm is turned on, and the switch tube controlling the lower bridge arm of the third bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the third interval, the switch tube controlling the lower bridge arm of the third bridge arm of the three-phase bridge arm is turned on, and the switch tube controlling the upper bridge arm of the third bridge arm of the three-phase bridge arm is turned off.

[0190] The time interval between the start time of the first interval and the start time of the second interval is set, and the time interval between the start time of the second interval and the start time of the third interval is also set. During the second cycle, the current amplitude output by the motor controller is zero.

[0191] Based on the same concept, this application also provides an electric vehicle, including the power battery charging device shown in the above embodiments.

[0192] Based on the same concept, embodiments of this application provide a computer-readable storage medium storing program code that, when run on a computer, causes the computer to perform the above-described method.

[0193] Figure 11 is a schematic diagram of a chip structure. Based on the same concept, embodiments of this application provide a chip, which includes a processor coupled to a memory. The processor is used to execute computer programs or instructions stored in the memory to implement the above-described method.

[0194] In implementation, each step of the above method can be completed by the integrated logic circuitry of the hardware in processor 1101 or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly implemented by the hardware processor, or by a combination of hardware and software modules in processor 1101. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory 1102, and processor 1101 reads information from memory 1102 and, in conjunction with its hardware, completes the steps of the above method.

[0195] It should be understood that the processor 1101 described above can be a chip. For example, the processor 1101 can be a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0196] It is understood that the memory 1102 in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0197] In this embodiment of the application, the memory 1102 is used to store instructions, and the processor 1101 is used to execute the instructions stored in the memory 1102 to implement the above method.

[0198] As used in this specification, the terms "component," "unit," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0199] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0200] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0201] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0202] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0203] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0204] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0205] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the above claims.

Claims

1. A power battery charging device, characterized in that, The device includes a DC positive port, a DC negative port, a power battery positive port, a power battery negative port, and a motor controller. The DC positive port is used to connect to the positive terminal of the DC charging pile output, the DC negative port is used to connect to the negative terminal of the DC charging pile output, the power battery positive port is used to connect to the positive terminal of the power battery, and the power battery negative port is used to connect to the negative terminal of the power battery. The motor controller includes a power circuit and a bus capacitor. The midpoints of the three-phase bridge arms of the power circuit are respectively used to connect the three-phase windings of the motor. The two ends of each phase bridge arm of the power circuit are respectively connected to the two ends of the bus capacitor. One end of the bus capacitor is used to connect to the DC positive port, and the other end of the bus capacitor is used to connect to the DC negative port. The center tap of the three-phase winding is also used to connect to the positive port of the power battery. The low potential end of each phase arm of the power circuit is used to connect to the negative port of the power battery. The motor controller is used to receive the DC power output from the DC charging pile and perform power conversion on the DC power to perform pulse charging for the power battery.

2. The apparatus according to claim 1, characterized in that, The DC charging pile charges the power battery in a first cycle and a second cycle. During the first cycle, the motor controller is used to receive the DC power output from the DC charging pile and perform power conversion on the DC power to charge the power battery with a current of a set amplitude. During the second cycle, the current amplitude output by the motor controller is zero.

3. The apparatus according to claim 2, characterized in that, The device further includes a controller that, within a first sub-interval of the first cycle, controls the switching transistor of the upper arm of at least one of the three-phase bridge arms to be turned on and controls the switching transistor of the lower arm of at least one of the three-phase bridge arms to be turned off; and within a second sub-interval of the first cycle, controls the switching transistor of the lower arm of at least one of the three-phase bridge arms to be turned on and controls the switching transistor of the upper arm of at least one of the three-phase bridge arms to be turned off.

4. The apparatus according to claim 3, characterized in that, The controller is used to acquire the output voltage of the DC charging pile and the rated voltage of the power battery, and to determine the duration of the first sub-interval and the second sub-interval based on the output voltage of the DC charging pile and the rated voltage of the power battery.

5. The apparatus according to claim 3, characterized in that, The controller is used for: During the second cycle, each switch in the three-phase bridge arm is disconnected.

6. The apparatus according to claim 2, characterized in that, The controller is configured to: acquire the voltage of the power battery during the first cycle, and determine whether to switch to execute the action of the second cycle based on the voltage of the power battery and a first set voltage threshold.

7. The apparatus according to claim 2, characterized in that, The controller is configured to: acquire the voltage of the power battery during the second cycle, and determine whether to switch to execute the action of the first cycle based on the voltage of the power battery and a second set voltage threshold.

8. The apparatus according to any one of claims 1-7, characterized in that, During the charging process of the DC charging pile for the power battery, the in-vehicle load is connected to both ends of the power battery and is in a state of power consumption.

9. The apparatus according to claim 2, characterized in that, During the second cycle, the power battery is used to supply power to the loads inside the vehicle.

10. The apparatus according to claim 2, characterized in that, The device further includes at least one control switch, which corresponds to at least one in-vehicle load. The in-vehicle load is connected to both ends of the power battery through the corresponding control switch. During the second cycle, the controller is used to control the at least one control switch to be turned on.

11. The apparatus according to any one of claims 1-10, characterized in that, When the motor controller controls the motor to drive the wheel, one end of the bus capacitor is disconnected from the DC positive port, and the other end of the bus capacitor is disconnected from the DC negative port; the high potential end of each phase arm of the power circuit is connected to the positive port of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative port of the power battery; the motor controller receives the DC power output from the power battery and controls the motor to drive the wheel.

12. The apparatus according to any one of claims 1-11, characterized in that, When the motor controller determines that the output of the DC charging pile is pulsed DC, one end of the bus capacitor is connected to the positive DC port, and the other end of the bus capacitor is connected to the negative DC port; the high potential end of each phase arm of the power circuit is connected to the positive port of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative port of the power battery, and the DC charging pile performs pulse charging for the power battery.

13. The apparatus according to any one of claims 1-11, characterized in that, The device also includes a first charging pile switch, a second charging pile switch, a first battery switch, a second battery switch, and a third battery switch; One end of the bus capacitor is used to connect to the DC positive port through the first charging pile switch, and the other end of the bus capacitor is used to connect to the DC negative port through the second charging pile switch; the center tap of the three-phase winding is also used to connect to the positive port of the power battery through the first battery switch; the high potential end of each phase bridge arm of the power circuit is used to connect to the positive port of the power battery through the second battery switch, and the low potential end of each phase bridge arm of the power circuit is used to connect to the negative port of the power battery through the third battery switch.

14. The apparatus according to claim 13, characterized in that, The device also includes a controller. During the process of the DC charging pile charging the power battery, the controller is used to control the first charging pile switch, the second charging pile switch, the first battery switch and the third battery switch to be turned on, and the second battery switch to be turned off; When the motor controller controls the motor to drive the wheel, the controller is used to control the second battery switch and the third battery switch to be turned on, and the first charging pile switch, the second charging pile switch and the first battery switch to be turned off. When the motor controller determines that the output of the DC charging pile is pulsed DC power, the first charging pile switch, the second charging pile switch, the second battery switch, and the third battery switch are turned on, and the first battery switch is turned off.

15. The apparatus according to any one of claims 1-14, characterized in that, The DC charging pile charges the power battery in a first cycle and a second cycle. The device further includes a controller, which includes a first interval, a second interval, and a third interval in the first cycle; The controller is used for: In the first sub-interval of the first interval, the switch of the upper bridge arm of the first bridge arm of the three-phase bridge arm is turned on, and the switch of the lower bridge arm of the first bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the first interval, the switch of the lower bridge arm of the first bridge arm of the three-phase bridge arm is turned on, and the switch of the upper bridge arm of the first bridge arm of the three-phase bridge arm is turned off. In the first sub-interval of the second interval, the switch of the upper bridge arm of the second bridge arm of the three-phase bridge arm is turned on, and the switch of the lower bridge arm of the second bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the second interval, the switch of the lower bridge arm of the second bridge arm of the three-phase bridge arm is turned on, and the switch of the upper bridge arm of the second bridge arm of the three-phase bridge arm is turned off. In the first sub-interval of the third interval, the switch of the upper bridge arm in the third bridge arm of the three-phase bridge arm is turned on, and the switch of the lower bridge arm in the third bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the third interval, the switch of the lower bridge arm in the third bridge arm of the three-phase bridge arm is turned on, and the switch of the upper bridge arm in the third bridge arm of the three-phase bridge arm is turned off. The start time of the first interval and the start time of the second interval are separated by a set time interval, and the start time of the second interval and the start time of the third interval are separated by a set time interval. During the second cycle, the current amplitude output by the motor controller is zero.

16. A pulse charging method, characterized in that, Applied to electric vehicles, the motor controller in the electric vehicle includes a power circuit and a bus capacitor. The midpoints of the three-phase bridge arms of the power circuit are respectively used to connect the three-phase windings of the motor. The two ends of each phase bridge arm of the power circuit are respectively connected to the two ends of the bus capacitor. The method includes: During the process of charging the power battery using a DC charging pile, one end of the bus capacitor is connected to the positive terminal of the DC charging pile output, and the other end of the bus capacitor is connected to the negative terminal of the DC charging pile output; the center tap of the three-phase winding is connected to the positive terminal of the power battery, and the low potential end of each phase bridge arm of the power circuit is connected to the negative terminal of the power battery. The motor controller receives DC power output from the DC charging pile and performs power conversion on the DC power to provide pulse charging for the power battery.

17. The method according to claim 16, characterized in that, The process of controlling the motor controller to receive DC power output from the DC charging pile and to perform power conversion on the DC power to provide pulse charging for the power battery includes: During the first cycle, the motor controller receives the DC power output from the DC charging pile and performs power conversion on the DC power, then charges the power battery with a current of a set amplitude. During the second cycle, the current amplitude output by the motor controller is zero.

18. The method according to claim 16, characterized in that, Controlling the motor controller to receive DC power output from the DC charging pile and to perform power conversion on the DC power to provide pulse charging for the power battery includes: In the first sub-interval of the first cycle, the switch of the upper arm of at least one of the three-phase bridge arms is turned on, and the switch of the lower arm of at least one of the three-phase bridge arms is turned off. In the second sub-interval of the first cycle, the switch of the lower arm of at least one of the three-phase bridge arms is turned on, and the switch of the upper arm of at least one of the three-phase bridge arms is turned off.

19. The method according to claim 18, characterized in that, The method further includes: obtaining the output voltage of the DC charging pile and the rated voltage of the power battery, and determining the duration of the first sub-interval and the second sub-interval based on the output voltage of the DC charging pile and the rated voltage of the power battery.

20. The method according to claim 17, characterized in that, The method specifically includes: During the second cycle, each switch in the three-phase bridge arm is disconnected.

21. The method according to claim 17, characterized in that, The method further includes: during the first cycle, acquiring the voltage of the power battery, and determining whether to switch to execute the action of the second cycle based on the voltage of the power battery and a first set voltage threshold.

22. The method according to claim 17, characterized in that, The method further includes: during the second cycle, acquiring the voltage of the power battery, and determining whether to switch to execute the action of the first cycle based on the voltage of the power battery and a second set voltage threshold.

23. The method according to claim 16, characterized in that, The method further includes: During the charging process of the DC charging pile for the power battery, the load inside the vehicle is connected to both ends of the power battery, and the load inside the vehicle is in a state of power consumption.

24. The method according to claim 16, characterized in that, The method further includes: during the second cycle, controlling the in-vehicle load to be connected to both ends of the power battery so that the power battery supplies power to the in-vehicle load.

25. The method according to any one of claims 16-24, characterized in that, The method further includes: When the motor controller controls the motor to drive the wheels, one end of the bus capacitor is disconnected from the positive terminal of the DC charging pile, and the other end of the bus capacitor is disconnected from the negative terminal of the DC charging pile; the high potential end of each phase arm of the power circuit is connected to the positive terminal of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative terminal of the power battery; the motor controller receives the DC power output from the power battery and controls the motor to drive the wheels.

26. The method according to any one of claims 16-24, characterized in that, The method further includes: When the motor controller determines that the output of the DC charging pile is pulsed DC power, one end of the bus capacitor is connected to the positive terminal of the DC charging pile, and the other end of the bus capacitor is connected to the negative terminal of the DC charging pile; the high potential end of each phase arm of the power circuit is connected to the positive terminal of the power battery, and the low potential end of each phase arm of the power circuit is connected to the negative terminal of the power battery, and the DC charging pile performs pulse charging for the power battery.

27. The method according to any one of claims 16-24, characterized in that, The process of controlling the motor controller to receive DC power output from the DC charging pile and to perform power conversion on the DC power to provide pulse charging for the power battery includes: The DC charging pile charges the power battery in a first cycle and a second cycle, and the first cycle includes a first interval, a second interval and a third interval. The method further includes: In the first sub-interval of the first interval, the switch of the upper bridge arm of the first bridge arm of the three-phase bridge arm is turned on, and the switch of the lower bridge arm of the first bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the first interval, the switch of the lower bridge arm of the first bridge arm of the three-phase bridge arm is turned on, and the switch of the upper bridge arm of the first bridge arm of the three-phase bridge arm is turned off. In the first sub-interval of the second interval, the switch of the upper bridge arm of the second bridge arm of the three-phase bridge arm is turned on, and the switch of the lower bridge arm of the second bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the second interval, the switch of the lower bridge arm of the second bridge arm of the three-phase bridge arm is turned on, and the switch of the upper bridge arm of the second bridge arm of the three-phase bridge arm is turned off. In the first sub-interval of the third interval, the switch of the upper bridge arm in the third bridge arm of the three-phase bridge arm is turned on, and the switch of the lower bridge arm in the third bridge arm of the three-phase bridge arm is turned off. In the second sub-interval of the third interval, the switch of the lower bridge arm in the third bridge arm of the three-phase bridge arm is turned on, and the switch of the upper bridge arm in the third bridge arm of the three-phase bridge arm is turned off. The start time of the first interval and the start time of the second interval are separated by a set time interval, and the start time of the second interval and the start time of the third interval are separated by a set time interval. During the second cycle, the current amplitude output by the motor controller is zero.

28. An electric vehicle, characterized in that, Includes the power battery charging device as described in any one of claims 1-15.

29. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed by a computer, cause the method as described in any one of claims 16-27 to be implemented.

30. A computer program product, characterized in that, The computer program product includes a computer program or instructions that, when executed on a computer, cause the method as described in any one of claims 16-27 to be implemented.

31. A chip, characterized in that, The chip includes a processor coupled to a memory, the processor being configured to execute a computer program or instructions stored in the memory to implement the method as described in any one of claims 16-27.

Images