Power battery pre-charging control circuit, vehicle and power battery pre-charging control method

Abstract

This invention relates to the field of vehicles, and more particularly to a power battery pre-charge control circuit, a vehicle, and a power battery pre-charge control method. This invention controls the electronic fan to reverse to output a high-voltage pre-charge signal, so that the bus capacitor can be pre-charged based on the high-voltage pre-charge signal. When the voltage across the bus capacitor is close to the total voltage of the power battery system, the relay contacts are closed, thus avoiding the problem in the prior art where repeated power cycling in vehicles can damage the pre-charge circuit and affect vehicle operation.

Description

Technical Field

[0001] This invention relates to the field of vehicles, and more particularly to a power battery pre-charge control circuit, a vehicle, and a power battery pre-charge control method. Background Technology

[0002] Traditional electric vehicle high-voltage power-on process requires pre-charging through a pre-charging circuit to achieve a voltage difference across the main relay before closing the main relay. This is to prevent the large current surge from the high voltage difference from damaging the electrical circuit. Most traditional electric vehicles use a pre-charging circuit with a pre-charging resistor and a pre-charging relay to achieve high-voltage pre-charging. However, in this method, the pre-charging resistor heats up during the pre-charging process. Frequent power-on and power-off cycles cause the resistor to overheat and cannot dissipate heat in time, which can damage the pre-charging circuit. In addition, the overheating of the resistor causes temperature drift in the pre-charging resistance value, resulting in unstable pre-charging time. Summary of the Invention

[0003] The main objective of this invention is to provide a power battery pre-charge control circuit, a vehicle, and a power battery pre-charge control method, aiming to avoid the problem in the prior art where repeated power cycling in a vehicle can damage the pre-charge circuit and affect vehicle operation.

[0004] To achieve the above objectives, the present invention provides a power battery pre-charge control circuit, which includes a pre-charge circuit, a switching circuit, and a power battery circuit, wherein the pre-charge circuit, the switching circuit, and the power battery circuit are connected in sequence.

[0005] The pre-charging circuit is used to receive a high-voltage start signal and generate a high-voltage pre-charging signal based on the high-voltage start signal.

[0006] The switching circuit is used to receive the high-voltage precharge signal and control the opening and closing state of the switching circuit according to the high-voltage precharge signal.

[0007] The power battery circuit is used to output a high-voltage signal to complete high-voltage power-on when the switch is closed in the open / closed state.

[0008] Optionally, the pre-charging circuit includes: an electronic fan control module and an electronic fan motor;

[0009] The first input terminal of the electronic fan control module is connected to the vehicle controller, the first output terminal of the electronic fan control module is connected to the input terminal of the electronic fan motor, the output terminal of the electronic fan motor is connected to the second input terminal of the electronic fan control module, and the second output terminal of the electronic fan control module is connected to the second terminal of the switching circuit.

[0010] Optionally, the electric fan motor includes: a primary winding and a secondary high-voltage winding;

[0011] The primary coil winding is connected to the first output terminal of the electronic fan controller, and the secondary high-voltage coil winding is connected to the second input terminal of the electronic fan controller.

[0012] Optionally, the pre-charging circuit further includes: a first relay contact and a first diode;

[0013] The anode of the first diode is connected to the output terminal of the electronic fan motor, the cathode of the first diode is connected to the second terminal of the first relay contact, and the first terminal of the first relay contact is connected to the second input terminal of the electronic fan control module.

[0014] Optionally, the power battery precharge control circuit further includes a motor control circuit, wherein the input terminal of the motor control circuit is connected to the second terminal of the switch circuit and the second output terminal of the electronic fan control module U1, respectively.

[0015] The motor control circuit is used to receive the high-voltage precharge signal;

[0016] The motor control circuit is also used to precharge according to the high-voltage precharge signal.

[0017] Optionally, the motor control circuit includes: a first capacitor, a power control module, and a second motor;

[0018] Wherein, the first end of the first capacitor is connected to the first interface of the second output terminal of the electronic fan control module and the first input terminal of the power control module, the second end of the first capacitor is connected to the second interface of the second output terminal of the electronic fan control module and the second input terminal of the power control module, the first output terminal of the power control module is connected to the first input terminal of the second motor, the second output terminal of the power control module is connected to the second input terminal of the second motor, and the third output terminal of the power control module is connected to the third input terminal of the second motor.

[0019] Optionally, the power battery circuit includes: a battery pack connected in sequence.

[0020] Optionally, the switching circuit includes: a second relay contact and a third relay contact;

[0021] Wherein, the first end of the second relay contact is connected to the positive terminal of the battery pack, the second end of the second relay contact is connected to the first interface of the second output terminal of the electronic fan controller, the first end of the third relay contact is connected to the negative terminal of the battery pack, and the second end of the third relay contact is connected to the second interface of the second output terminal of the electronic fan controller.

[0022] The present invention also provides a vehicle, the vehicle including the power battery precharge control circuit as described above.

[0023] The present invention also provides a power battery pre-charge control method, wherein the power battery pre-charge control method is applied to the power battery pre-charge control circuit described above, and the power battery pre-charge control method includes:

[0024] Upon receiving a high-voltage start signal, a PWM pulse signal is generated based on the high-voltage start signal;

[0025] The operating state of the electronic fan motor is controlled based on the PWM pulse signal and the preset first motor working strategy;

[0026] The high-voltage pre-charge signal output by the electronic fan motor is obtained, and the bus voltage is determined based on the high-voltage pre-charge signal;

[0027] Based on the bus signal and the preset battery pack voltage, the power battery is controlled to complete high-voltage pre-charging.

[0028] This invention discloses a power battery pre-charge control circuit, comprising: a pre-charge circuit, a switching circuit, and a power battery circuit, wherein the pre-charge circuit, the switching circuit, and the power battery circuit are connected sequentially; the pre-charge circuit is used to receive a high-voltage start signal and generate a high-voltage pre-charge signal based on the high-voltage start signal; the switching circuit is used to receive the high-voltage pre-charge signal and control the opening and closing state of the switching circuit based on the high-voltage pre-charge signal; the power battery circuit is used to output a high-voltage signal when the switch is closed, thereby completing high-voltage power-on. This invention reverses the electronic fan to output a high-voltage pre-charge signal, so that the bus capacitor is pre-charged based on the high-voltage pre-charge signal, avoiding the problem in the prior art where repeated power-on and power-off cycles in vehicles can damage the pre-charge circuit and affect vehicle operation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the first embodiment of the power battery pre-charge control circuit of the present invention;

[0031] Figure 2 This is a circuit diagram of the first embodiment of the power battery pre-charge control circuit of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the second embodiment of the power battery pre-charge control method of the present invention;

[0033] Figure 4 This is a schematic diagram of the coil winding of the electronic fan in the pre-charge control circuit of the power battery of the present invention.

[0034] Explanation of icon numbers:

[0035]

[0036] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0037] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0040] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, the user should consider such a combination of technical solutions to be non-existent and not within the scope of protection claimed by this invention.

[0041] refer to Figure 1 , Figure 2 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the power battery pre-charge control circuit of the present invention; Figure 2 This is a schematic diagram of the circuit structure of the first embodiment of the power battery precharge control circuit of the present invention;

[0042] This invention discloses a power battery pre-charge control circuit, which includes a pre-charge circuit 10, a switching circuit 20, and a power battery circuit 30, wherein the pre-charge circuit 10, the switching circuit 20, and the power battery circuit 30 are connected in sequence.

[0043] The pre-charging circuit 10 is used to receive a high-voltage start signal and generate a high-voltage pre-charging signal based on the high-voltage start signal.

[0044] The switching circuit 20 is used to receive the high voltage precharge signal and control the opening and closing state of the switching circuit 20 according to the high voltage precharge signal.

[0045] The power battery circuit 30 is used to output a high-voltage signal to complete the high-voltage power-on when the switch is closed in the open / closed state.

[0046] It should be noted that the high-voltage start signal can be a signal output by the vehicle controller, used to control the pre-charging circuit 10 to be powered on, thereby generating a high-voltage pre-charging signal. In this embodiment, the connections between the various circuits are made through two-phase power.

[0047] It is worth noting that when a vehicle is powered on, due to the capacitive load in the electric vehicle's power supply circuit, the high-voltage system relay will suddenly close at the instant the circuit is connected. At this time, the capacitor's charge is zero. According to the transient characteristics of the circuit, the capacitor is equivalent to a short circuit, and the circuit resistance is low. The circuit resistance includes the battery's internal resistance, the high-voltage line resistance, the contact resistance of each contact point, and the internal resistance of the fuse. Therefore, the transient current of the high-voltage system becomes very large, resulting in a large current surge of several thousand amperes. This transient surge current will not only burn out the main and negative relays, but also cause serious damage to the entire power supply circuit and other electrical equipment. It may also endanger the personal safety of the driver and passengers.

[0048] In this embodiment, the high-voltage pre-charge signal can charge the bus capacitor. When the voltage difference across the bus capacitor reaches a preset threshold, the switch circuit 20 will be closed, thereby enabling the power battery system to provide operating voltage to the motor controller. The preset threshold can be the total voltage of the power battery system, that is, when the circuit is connected, the voltage across the switch is equal or close, thereby avoiding transient inrush current when the circuit is closed. This avoids the problem in the prior art where repeated power-on and power-off cycles can damage the pre-charge circuit and affect vehicle operation.

[0049] In practice, when the voltage across the bus capacitor is greater than or equal to 95% of the total voltage of the power battery system, the switch circuit 20 can be closed and the high-voltage switch inside the electronic fan can be disconnected, thereby completing the high-voltage power-on process.

[0050] The pre-charging circuit 10 includes an electronic fan control module U1 and an electronic fan motor M1. The first input terminal of the electronic fan control module U1 is connected to the vehicle controller, the first output terminal of the electronic fan control module U1 is connected to the input terminal of the electronic fan motor M1, the output terminal of the electronic fan motor M1 is connected to the second input terminal of the electronic fan control module U1, and the second output terminal of the electronic fan control module U1 is connected to the second terminal of the switching circuit 20.

[0051] In the specific implementation, the vehicle controller inputs a 12V high-voltage start signal to the electric fan control module U1. The electric fan control module U1 generates a PWM pulse signal based on the high-voltage start signal and transmits the PWM pulse signal to the electric fan motor M1, thereby controlling the 12V electric fan to reverse and gradually increase the speed to improve the high-voltage output voltage, realize the charging of the bus capacitor and gradually increase the voltage to be comparable to the voltage at the power battery terminal, and realize the pre-charging function.

[0052] The electronic fan motor M1 includes a primary coil winding and a secondary high-voltage coil winding. The primary coil winding is connected to the first output terminal of the electronic fan controller, and the secondary high-voltage coil winding is connected to the second input terminal of the electronic fan controller.

[0053] It should be noted that, in order to ensure that the coil winding in the electric fan motor M1 can meet the boosting requirements, in this embodiment, the electric fan motor M1 also adds a secondary high-voltage winding to meet the high-voltage pre-charge requirements.

[0054] The pre-charging circuit further includes: a first relay contact KM1 and a first diode D1; the anode of the first diode D1 is connected to the output terminal of the electronic fan motor, the cathode of the first diode D1 is connected to the second terminal of the first relay contact KM1, and the first terminal of the first relay contact KM1 is connected to the second input terminal of the electronic fan control module U1.

[0055] In this embodiment, since the rotation direction of the electric fan motor M1 during high-voltage pre-charging is different from that during normal heat dissipation, in order to prevent the working current generated by the electric fan motor M1 during normal operation from flowing back into the electric fan control module U1 and causing interference to the vehicle's high-voltage system, a unidirectional diode is added to achieve current interception.

[0056] The power battery precharge control circuit also includes a motor control circuit 40, the input terminal of which is connected to the second terminal of the switch circuit 20 and the second output terminal of the electronic fan control module U1, respectively.

[0057] The motor control circuit 40 is used to receive the high-voltage precharge signal;

[0058] The motor control circuit 40 is also used to precharge according to the high-voltage precharge signal.

[0059] The motor control circuit 40 includes: a first capacitor C1, a power control module U2, and a second motor M2;

[0060] Wherein, the first end of the first capacitor C1 is connected to the first interface of the second output terminal of the electronic fan control module U1 and the first input terminal of the power control module U2, respectively. The second end of the first capacitor C1 is connected to the second interface of the second output terminal of the electronic fan control module U1 and the second input terminal of the power control module U2, respectively. The first output terminal of the power control module U2 is connected to the first input terminal of the second motor M2, the second output terminal of the power control module U2 is connected to the second input terminal of the second motor M2, and the third output terminal of the power control module U2 is connected to the third input terminal of the second motor M2.

[0061] It is understandable that the first capacitor C1 refers to the bus capacitor. During high-voltage pre-charging, the high-voltage pre-charging signal generated by the rotation of the electric fan motor M1 will charge the first capacitor C1. When the voltage across the first capacitor C1 is greater than or equal to 95% of the total voltage of the power battery system, the switch circuit 20 can be closed and the high-voltage switch inside the electric fan can be disconnected, thereby completing the high-voltage power-on process.

[0062] The power battery circuit 30 includes: a battery pack connected in sequence.

[0063] The switching circuit 20 includes: a second relay contact KM2 and a third relay contact KM3;

[0064] Specifically, the first end of the second relay contact KM2 is connected to the positive terminal of the battery pack, the second end of the second relay contact KM2 is connected to the first interface of the second output terminal of the electronic fan controller, the first end of the third relay contact KM3 is connected to the negative terminal of the battery pack, and the second end of the third relay contact KM3 is connected to the second interface of the second output terminal of the electronic fan controller.

[0065] In this embodiment, the second relay contact KM2 can be a main positive relay contact, and the third relay contact KM3 can be a main negative relay contact. This embodiment does not impose specific restrictions on this.

[0066] This embodiment discloses that the high-voltage pre-charge signal is generated by the rotation of the electric fan motor M1, thereby charging the bus capacitor. When the voltage across the bus capacitor approaches the total voltage of the power battery system, the relay contacts will be closed to complete the high-voltage pre-charge function.

[0067] This invention provides a method for controlling the pre-charge of a power battery, referring to... Figure 3 , Figure 3 This is a flowchart illustrating the first embodiment of a power battery pre-charge control method according to the present invention.

[0068] In this embodiment, the power battery pre-charge control method includes the following steps:

[0069] Step S10: Upon receiving the high-voltage start signal, generate a PWM pulse signal based on the high-voltage start signal;

[0070] It should be noted that the execution subject of this embodiment of the invention can be a vehicle controller, or other devices with the same or similar functions. This embodiment does not impose any specific limitations on this.

[0071] Step S20: Control the operating state of the electronic fan motor M1 based on the PWM pulse signal and the preset first motor operating strategy;

[0072] It is worth noting that the high-voltage start signal refers to the control signal input by the user, which is used to start the electronic fan control module U1 to generate a PWM pulse signal.

[0073] It is understood that the preset first motor working strategy may include, but is not limited to, the rotation direction of the electric fan motor M1 and the start-up time of the electric fan motor M1, etc., and this embodiment does not impose specific restrictions on this.

[0074] In the specific implementation, after obtaining the PWM pulse signal, the timing, power and speed of the electric fan rotation are determined according to the PWM pulse signal. By transmitting the PWM pulse signal to the electric fan motor M1, the electric fan motor M1 can run counterclockwise according to the timing, power and speed of the electric fan rotation, thereby outputting high voltage through the principle of generating electricity by rotating magnetic field of permanent magnet.

[0075] In this embodiment, reference Figure 4 The electric fan motor M1 can use a low-voltage 12V cooling electric fan coil. In addition, a large turns ratio coil circuit is added next to the low-voltage coil. The typical ratio of the number of coil turns to the primary side is 1:(25~40), which meets the pre-charge requirement of 12V to 300~480V voltage.

[0076] Step S30: Obtain the high-voltage pre-charge signal output by the electronic fan motor M1, and determine the bus voltage based on the high-voltage pre-charge signal;

[0077] It should be understood that the bus voltage refers to the voltage across the first capacitor C1. When the bus voltage approaches the total voltage of the vehicle's power battery system, the relay contacts close, thereby enabling the vehicle's power battery system to supply power to the motor controller and complete the pre-charging. For example, when the capacitance across the first capacitor C1 is greater than or equal to 95% of the total voltage of the power battery system, the switch circuit 20 can be closed, and the high-voltage switch inside the electric fan can be disconnected, thereby completing the high-voltage power-on process.

[0078] Step S40: Based on the bus signal and the preset battery pack voltage, control the power battery to complete the high-voltage power-on pre-charge.

[0079] It should be understood that the preset battery pack voltage refers to the total voltage of multiple battery packs connected in sequence.

[0080] The step of controlling the power battery to complete high-voltage pre-charging based on the bus signal and the preset battery pack voltage includes:

[0081] The voltage deviation is determined based on the bus voltage and the preset battery pack voltage;

[0082] When the voltage deviation is less than a preset threshold, the main positive relay is controlled to close, so that the power battery outputs a high-voltage power-on signal to complete the high-voltage power-on pre-charge.

[0083] This embodiment discloses that upon receiving a high-voltage start signal, a PWM pulse signal is generated based on the high-voltage start signal; the operating state of the electric fan motor M1 is controlled based on the PWM pulse signal and a preset first motor operating strategy; the high-voltage pre-charge signal output by the electric fan motor M1 is acquired, and the bus voltage is determined based on the high-voltage pre-charge signal; the power battery is controlled to complete high-voltage pre-charge based on the bus signal and a preset battery pack voltage. Compared with the prior art, this embodiment generates a PWM pulse signal to control the operation of the electric fan motor M1 based on the high-voltage start signal, thereby controlling the electric fan motor M1 to generate a high-voltage pre-charge signal to charge the bus capacitor, thereby controlling the closing of the relay contacts to achieve high-voltage pre-charge. This avoids the problem in the prior art where repeated power-on and power-off cycles in vehicles can damage the pre-charge circuit and affect vehicle operation.

[0084] Since this vehicle adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0085] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0086] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0087] In addition, for technical details not described in detail in this embodiment, please refer to the power battery pre-charge control circuit provided in any embodiment of the present invention, which will not be repeated here.

[0088] Furthermore, it should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0089] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0090] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A power battery pre-charge control circuit, characterized in that, The power battery pre-charge control circuit includes: a pre-charge circuit, a switching circuit, and a power battery circuit, wherein the pre-charge circuit, the switching circuit, and the power battery circuit are connected in sequence. The pre-charging circuit is used to receive a high-voltage start signal and generate a high-voltage pre-charging signal based on the high-voltage start signal. The pre-charging circuit includes: an electronic fan control module and an electronic fan motor, wherein the electronic fan motor includes: a primary coil winding and a secondary coil high-voltage winding; The first input terminal of the electronic fan control module is connected to the vehicle controller, the first output terminal of the electronic fan control module is connected to the input terminal of the electronic fan motor, the output terminal of the electronic fan motor is connected to the second input terminal of the electronic fan control module, and the second output terminal of the electronic fan control module is connected to the second terminal of the switching circuit. The electronic fan control module is configured to generate a PWM pulse signal in response to the high-voltage start signal and control the electronic fan motor to reverse based on the PWM pulse signal, so as to output the high-voltage precharge signal through the high-voltage winding of the secondary coil. The primary coil winding is connected to the first output terminal of the electronic fan control module, and the secondary coil high voltage winding is connected to the second input terminal of the electronic fan control module. The switching circuit is used to receive the high-voltage precharge signal and control the opening and closing state of the switching circuit according to the high-voltage precharge signal. The power battery circuit is used to output a high-voltage signal to complete high-voltage power-on when the switch is closed in the open / closed state.

2. The power battery pre-charge control circuit as described in claim 1, characterized in that, The pre-charging circuit further includes: a first relay contact and a first diode; The anode of the first diode is connected to the output terminal of the electronic fan motor, the cathode of the first diode is connected to the second terminal of the first relay contact, and the first terminal of the first relay contact is connected to the second input terminal of the electronic fan control module.

3. The power battery pre-charge control circuit as described in claim 1, characterized in that, The power battery pre-charge control circuit further includes a motor control circuit, the input terminal of which is connected to the second terminal of the switch circuit and the second output terminal of the electronic fan control module, respectively. The motor control circuit is used to receive the high-voltage precharge signal; The motor control circuit is also used to precharge according to the high-voltage precharge signal.

4. The power battery pre-charge control circuit as described in claim 3, characterized in that, The motor control circuit includes: a first capacitor, a power control module, and a second motor; Wherein, the first end of the first capacitor is connected to the first interface of the second output terminal of the electronic fan control module and the first input terminal of the power control module, the second end of the first capacitor is connected to the second interface of the second output terminal of the electronic fan control module and the second input terminal of the power control module, the first output terminal of the power control module is connected to the first input terminal of the second motor, the second output terminal of the power control module is connected to the second input terminal of the second motor, and the third output terminal of the power control module is connected to the third input terminal of the second motor.

5. The power battery pre-charge control circuit as described in claim 4, characterized in that, The power battery circuit includes: a battery pack connected in sequence.

6. The power battery pre-charge control circuit as described in claim 5, characterized in that, The switching circuit includes: a second relay contact and a third relay contact; Wherein, the first end of the second relay contact is connected to the positive terminal of the battery pack, the second end of the second relay contact is connected to the first interface of the second output terminal of the electronic fan control module, the first end of the third relay contact is connected to the negative terminal of the battery pack, and the second end of the third relay contact is connected to the second interface of the second output terminal of the electronic fan control module.

7. A vehicle, characterized in that, The vehicle includes a power battery pre-charge control circuit as described in any one of claims 1-6.

8. A power battery pre-charge control method, wherein the power battery pre-charge control method is applied to the power battery pre-charge control circuit as described in any one of claims 1-6, characterized in that, The power battery pre-charge control method includes: Upon receiving a high-voltage start signal, a PWM pulse signal is generated based on the high-voltage start signal; The operating state of the electronic fan motor is controlled based on the PWM pulse signal and the preset first motor working strategy; The high-voltage pre-charge signal output by the electronic fan motor is obtained, and the bus voltage is determined based on the high-voltage pre-charge signal; Based on the bus voltage and the preset battery pack voltage, the power battery is controlled to complete high-voltage pre-charging.

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