High-voltage switching control system and control method for double-battery-pack vehicle type

Abstract

The invention discloses a high-voltage switching control system and a high-voltage switching control method for a double-battery-pack vehicle type, which are used for controlling the switching between a main power battery pack and a standby power battery pack equipped on an electric vehicle, and the main power battery pack and the standby power battery pack are connected in parallel and then are connected to a load main loop to supply power to a load. A main IGBT module is arranged in series in a high-voltage loop where the main power battery pack is located, and a standby IGBT module is arranged in series in a high-voltage loop where the standby power battery pack is located; the IGBT driving module and the control module are correspondingly matched with the main IGBT module and the standby IGBT module respectively; and the control module determines a current PWM duty ratio according to a current voltage value and a current current value of a load main loop and / or a power switching instruction sent by a driver, and controls the on-off of the main IGBT module and the standby IGBT module according to the current PWM duty ratio, so that the main power battery pack and the standby power battery pack are switched to supply power to the load.

Description

Technical Field

[0001] The present invention relates to a system and a method, and in particular to a high-voltage switching control system and a control method for a dual-battery pack vehicle. Background Art

[0002] The insufficient range of electric vehicles has always been a concern for users.

[0003] In order to solve this problem, the "power bank" function is introduced in electric vehicles, that is, a set of power batteries is equipped on the whole vehicle to charge the original battery or directly drive the vehicle. When the vehicle is equipped with two battery packs, there will be a problem of power source switching.

[0004] In the prior art, high-voltage relays are used to control high-voltage circuits to enable the "power bank" to charge the original vehicle battery pack or switch the power source. However, when using high-voltage relays for control, considering that the relay actuation time is in the order of seconds and the load cut-off life is limited, it is suitable to charge the "power bank" and the original vehicle battery pack or switch the power source when the vehicle is stopped. If it is cut off under heavy load, such as while driving, there will be changes in vehicle speed and even power interruption, causing safety hazards.

[0005] Alternatively, the voltage difference between the two battery groups can be adjusted by adding DC / DC and DC / AC modules. However, when using DC / DC and DC / AC modules to switch between the two battery groups, the required equipment is large in size due to the high power of the vehicle load end, requiring space to be reserved for the entire vehicle, and long-term operation requires heat dissipation.

[0006] In addition, there is a solution that uses separation elements instead of electromechanical contactors, but the irreversible separation element can only be activated when all poles must be disconnected or the rescue separation point is activated by rescuers. It is suitable for rescue scenarios and has limited usage scenarios. Summary of the invention

[0007] In view of the drawbacks of the prior art, the present invention provides a high-voltage switching control system and a control method for a dual-battery pack vehicle.

[0008] The high-voltage switching control system for a dual-battery pack vehicle of the present invention is used to control the switching between the main power battery pack and the backup power battery pack equipped on the electric vehicle. The main power battery pack and the backup power battery pack are connected in parallel to the load main circuit and supply power to the load. The high-voltage circuit where the main power battery pack is located is provided with a main IGBT module in series, and the high-voltage circuit where the backup power battery pack is located is provided with a backup IGBT module in series.

[0009] It also includes an IGBT drive module and a control module respectively matched with the main IGBT module and the standby IGBT module;

[0010] The control module determines the current PWM duty cycle according to the current voltage value, current current value and / or power switching command issued by the driver of the load main circuit, and controls the on and off of the main IGBT module and the backup IGBT module with the current PWM duty cycle to realize switching between the main power battery pack and the backup power battery pack to power the load.

[0011] In the high-voltage switching control system for a dual-battery pack vehicle of the present invention, a main current-carrying diode is also arranged in series in the high-voltage circuit where the main power battery pack is located;

[0012] The high-voltage circuit where the backup power battery pack is located is also provided with a backup current-carrying diode in series.

[0013] In the high-voltage switching control system for a dual-battery pack vehicle model described in the present invention, the high-voltage circuit where the main power battery pack is located also includes a main charging branch;

[0014] The high-voltage circuit where the backup power battery pack is located also includes a backup charging branch.

[0015] In the high-voltage switching control system for a dual-battery pack vehicle of the present invention, the main charging branch includes a main regenerative charging relay and a first main current-carrying diode arranged in series, and the main regenerative charging relay and the first main current-carrying diode are arranged in series and then connected in reverse parallel with the main current-carrying diode;

[0016] The main charging branch further includes a second main current-passing diode which is arranged in reverse parallel with the main IGBT module.

[0017] In the high-voltage switching control system for a dual-battery pack vehicle of the present invention, the standby charging branch includes a standby regenerative charging relay and a first standby current-carrying diode arranged in series, and the standby regenerative charging relay and the first standby current-carrying diode are arranged in series and then connected in reverse parallel with the standby current-carrying diode;

[0018] The standby charging branch further includes a second standby pass diode which is connected in reverse parallel to the standby IGBT module.

[0019] In the high-voltage switching control method for a dual-battery pack vehicle of the present invention, a main power battery pack and a backup power battery pack are provided, and the main power battery pack and the backup power battery pack are connected in parallel and then connected to a load main circuit to supply power to the load;

[0020] A main IGBT module is arranged in series in the high-voltage circuit where the main power battery pack is located, a backup IGBT module is arranged in series in the high-voltage circuit where the backup power battery pack is located, and an IGBT drive module and a control module are arranged that are matched with the main IGBT module and the backup IGBT module respectively;

[0021] The control module determines the current PWM duty cycle according to the current voltage value, current current value and / or power switching command issued by the driver of the load main circuit, and controls the on and off of the main IGBT module and the backup IGBT module with the current PWM duty cycle to realize switching between the main power battery pack and the backup power battery pack to power the load.

[0022] In the high-voltage switching control method for a dual-battery pack vehicle of the present invention, a main current-carrying diode is arranged in series with the high-voltage circuit where the main power battery pack is located, and a main charging branch is arranged in the high-voltage circuit where the main power battery pack is located;

[0023] The main charging branch includes a main regenerative charging relay and a first main current-carrying diode which are arranged in series, and the main regenerative charging relay and the first main current-carrying diode are arranged in series and then connected in reverse parallel with the main current-carrying diode;

[0024] The main charging branch also includes a second main current-carrying diode which is arranged in reverse parallel with the main IGBT module;

[0025] A backup current-carrying diode is arranged in series in the high-voltage circuit where the backup power battery pack is located, and a backup charging branch is arranged in the high-voltage circuit where the backup power battery pack is located;

[0026] The standby charging branch includes a standby feedback charging relay and a first standby current-carrying diode which are arranged in series, and the standby feedback charging relay and the first standby current-carrying diode are arranged in series and then connected in reverse parallel with the standby current-carrying diode;

[0027] The standby charging branch further includes a second standby current-carrying diode which is arranged in reverse parallel with the standby IGBT module;

[0028] When the vehicle is driving, when the voltage of the main power battery pack is lower than that of the backup power battery pack, the following process is used to control the switch from the main power battery pack to the backup power battery pack:

[0029] The main IGBT module is closed, the main power battery pack supplies power to the load, the main regenerative charging relay is disconnected to turn off the vehicle regenerative mode, and the current PWM duty cycle is determined;

[0030] The standby IGBT module is closed, and the on and off of the standby IGBT module is controlled according to the current PWM duty cycle determined above. When the load circuit voltage reaches the voltage value of the standby power battery pack, the standby IGBT module remains on, and the main IGBT module is disconnected, and the standby power battery pack supplies power to the load;

[0031] Close the standby regenerative charging relay to start the vehicle regenerative mode.

[0032] In the high-voltage switching control method for a dual-battery pack vehicle of the present invention, when the voltage of the main power battery pack is higher than the voltage of the backup power battery pack during vehicle driving, the following process is used to control the switching from the main power battery pack to the backup power battery pack for powering the load:

[0033] The main IGBT module is closed, the main power battery pack supplies power to the load, and the main regenerative charging relay is disconnected to turn off the vehicle regenerative mode;

[0034] The backup IGBT module is closed and the main IGBT module is disconnected, and the backup power battery pack supplies power to the load;

[0035] Close the standby regenerative charging relay to start the vehicle regenerative mode.

[0036] In the high-voltage switching control method for a dual-battery pack vehicle of the present invention, when the vehicle is stopped, the main power battery pack is charged according to the following process:

[0037] Controlling the on and off of the main IGBT module according to a preset PWM duty cycle to slowly increase the voltage across the capacitor;

[0038] The main feedback charging relay is closed, the vehicle sends a request for charging current to the charging pile, and the charging of the main power battery pack starts.

[0039] In the high-voltage switching control system and control method for a dual-battery pack vehicle described in the present invention, by controlling the on-off frequency of the main IGBT module T1 and the backup IGBT module T2, the high-voltage circuit can be switched with load at any time without power interruption and without the need to stop the vehicle to switch between the two battery groups, thereby improving the convenience of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of the high-voltage switching control system for a dual-battery pack vehicle according to the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0042] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] like Figure 1As shown, the high-voltage switching control system and control method for dual-battery pack vehicles described in the present invention are suitable for vehicles equipped with two power battery packs, that is, electric vehicles equipped with a main power battery pack P1 and a backup power battery pack P2 (the backup power battery pack P2 can be composed of a single battery module, or multiple battery modules connected in series and parallel to supply power to the outside). In such electric vehicles, an on-board charger (i.e., OBC) that is adapted to AC charging will also be configured.

[0044] The high-voltage switching control system for a dual-battery pack vehicle described in the present invention is used to control the switching between the main power battery pack P2 and the backup power battery pack P3 equipped on the electric vehicle. The main power battery pack P1 and the backup power battery pack P2 are connected in parallel and connected to the load main circuit and supply power to the load. In the present invention, a main IGBT module T1 is arranged in series in the high-voltage circuit where the main power battery pack P1 is located, and a backup IGBT module T2 is arranged in series in the high-voltage circuit where the backup power battery pack P2 is located. At the same time, IGBT drive modules and control modules corresponding to the main IGBT module and the backup IGBT module are also matched and arranged respectively.

[0045] The control module can determine the current PWM duty cycle according to the current voltage value, current current value, and / or power switching command issued by the driver of the load main circuit, and control the on and off of the main IGBT module T1 and the backup IGBT module T2 with the current PWM duty cycle to realize the switch between the main power battery pack P1 and the backup power battery pack P2 to power the load, that is, the current main power battery pack P1 is switched to the backup power battery pack P2 to power the load, or the current backup power battery pack P2 is switched to the main power battery pack P1 to power the load. The present invention realizes the switching of the high-voltage circuit at any time with load by controlling the on and off frequency of the main IGBT module T1 and the backup IGBT module T2, and there is no power interruption, and there is no need to stop the vehicle to switch between the two groups of batteries, thereby improving the convenience of the whole vehicle.

[0046] In the high-voltage switching control system for a dual-battery pack vehicle described in the present invention, in order to prevent the phenomenon that the high-voltage battery charges the low-voltage battery due to the voltage difference during the switching process between the main power battery pack P1 and the backup power battery pack P2, a main current-passing diode D1 is also arranged in series in the high-voltage circuit where the main power battery pack P1 is located, and a backup current-passing diode D3 is also arranged in series in the high-voltage circuit where the backup power battery pack P2 is located.

[0047] In addition, in the high-voltage switching control system for a dual-battery pack vehicle model described in the present invention, the high-voltage circuit where the main power battery pack P1 is located also includes a main charging branch, and the high-voltage circuit where the backup power battery pack P2 is located also includes a backup charging branch. The main charging branch includes a main feedback charging relay W1 and a first main current-carrying diode D2 arranged in series, and the main feedback charging relay W1 and the first main current-carrying diode D2 are arranged in series and then reversely connected in parallel with the main current-carrying diode D1. The main charging branch also includes a second main current-carrying diode D5 arranged in reverse parallel with the main IGBT module T1. The backup charging branch includes a backup feedback charging relay W2 and a first backup current-carrying diode D4 arranged in series, and the backup feedback charging relay W2 and the first backup current-carrying diode D4 are arranged in series and then reversely connected in parallel with the backup current-carrying diode D3. The backup charging branch also includes a second backup current-carrying diode D6 arranged in reverse parallel with the backup IGBT module T2.

[0048] The present invention also discloses a high voltage switching control method for a dual battery pack vehicle, wherein the hardware system is as follows: Figure 1 As shown, a main power battery pack P1 and a backup power battery pack P2 are arranged on the electric vehicle, and the main power battery pack P1 and the backup power battery pack P2 are connected in parallel and connected to the load main circuit to supply power to the load. At the same time, a main IGBT module T1 is arranged in series with the high-voltage circuit where the main power battery pack P1 is located, and a backup IGBT module T2 is arranged in series with the high-voltage circuit where the backup power battery pack P2 is located, and an IGBT driving module and a control module are arranged to match the main IGBT module T1 and the backup IGBT module T2 respectively. The control module determines the current PWM duty cycle according to the current voltage value, current current value, and / or the power switching command issued by the driver of the load main circuit, and controls the on and off of the main IGBT module T1 and the backup IGBT module T2 with the current PWM duty cycle, so as to realize the switching between the main power battery pack P1 and the backup power battery pack P2 to supply power to the load. That is, the current main power battery pack P1 switches to the backup power battery pack P2, or the current backup power battery pack P2 switches to the main power battery pack P1. The present invention controls the on-off frequency of the main IGBT module T1 and the backup IGBT module T2, so as to realize the switching of the high-voltage circuit at any time without power interruption, and there is no need to stop the vehicle to switch between the two battery groups, thereby improving the convenience of the vehicle.

[0049] In the high-voltage switching control method for a dual-battery pack vehicle model described in the present invention, a main current-carrying diode D1 is also arranged in series in the high-voltage circuit where the main power battery pack P1 is located, and a main charging branch is arranged in the high-voltage circuit where the main power battery pack P1 is located; a backup current-carrying diode D3 is arranged in series in the high-voltage circuit where the backup power battery pack P2 is located, and a backup charging branch is arranged in the high-voltage circuit where the backup power battery pack P2 is located. Wherein, the main charging branch specifically includes a main feedback charging relay W1 and a first main current-carrying diode D2 arranged in series, and the main feedback charging relay W1 and the first main current-carrying diode D2 are arranged in series and then connected in reverse parallel with the main current-carrying diode D1. The main charging branch also includes a second main current-carrying diode D5 arranged in reverse parallel with the main IGBT module T1. The backup charging branch includes a backup feedback charging relay W2 and a first backup current-carrying diode D4 arranged in series, and the backup feedback charging relay W2 and the first backup current-carrying diode D4 are arranged in series and then connected in reverse parallel with the backup current-carrying diode D3. The standby charging branch further includes a second standby pass diode D6 which is connected in reverse parallel with the standby IGBT module T2.

[0050] During vehicle driving, when the voltage of the main power battery pack is lower than that of the backup power battery pack (i.e., the power of the main power battery pack P1 is about to be exhausted and needs to be switched to the backup power battery pack P2 for power supply), the following process can be used to control the switch from the main power battery pack to the backup power battery pack for powering the load:

[0051] At present, the main IGBT module T1 is closed, and the main power battery pack P1 supplies power to the load. At this time, if the power of the main power battery pack P1 is too low or the driver's instruction on power switching is received, the main regenerative charging relay W1 is disconnected to turn off the vehicle regenerative mode, and the time for the capacitor discharge to reach the MCU undervoltage protection value is calculated based on the collected load voltage and current values, and the current PWM duty cycle is determined by combining the capacitor impact current extreme value calculation;

[0052] Then, the standby IGBT module T2 is closed, and the on and off of the standby IGBT module T2 is controlled according to the current PWM duty cycle determined above, so that when the load circuit voltage reaches the voltage value of the standby power battery pack, the standby IGBT module T2 remains on, the standby power battery pack P2 supplies power to the load, and the main IGBT module T1 is disconnected. At this point, the switch from the main power battery pack P1 to the standby power battery pack P2 is completed, and the standby feedback charging relay W2 is closed to start the vehicle feedback mode.

[0053] During vehicle driving, there is another use case, that is, the driver wants to retain the power of the main power battery pack P1 and switch to the backup power battery pack P2 for power supply. At this time, the voltage of the main power battery pack is higher than the voltage of the backup power battery pack, and the control process is as follows: the main power battery pack switches to the backup power battery pack for powering the load:

[0054] The main IGBT module is currently closed, and the main power battery pack supplies power to the load. At this time, the driver's instruction on power switching is received. Since the voltage of the main power battery pack P1 is higher than the voltage of the backup power battery pack P2, for capacitor components, the process of switching from the main power battery pack P1 to the backup power battery pack P2 is a voltage drop process (discharge), and the switching of the power source at this time will not cause current shock. Therefore, the main feedback charging relay W1 can be disconnected to turn off the vehicle feedback mode;

[0055] Then, the standby IGBT module T2 is closed, and the main IGBT module T1 is disconnected, and the standby power battery pack P2 supplies power to the load;

[0056] Afterwards, the standby regenerative charging relay W2 is closed to start the vehicle regenerative mode.

[0057] In the present invention, when the vehicle stops for charging, control can be performed according to the following process (taking the charging of the main power battery pack P1 as an example):

[0058] The vehicle recognizes the charging pile signal, enters the charging process, and controls the on and off of the main IGBT module T1 according to the preset PWM duty cycle, so that the voltage across the capacitor slowly rises to 90% of the current voltage of the main power battery pack P1. ;

[0059] Then, the main feedback charging relay T1 is closed, the vehicle sends a request charging current to the charging pile, and the charging of the main power battery pack starts.

Claims

1. A high-voltage switching control system for a dual-battery pack vehicle, used to control the switching between the main power battery pack and the backup power battery pack equipped on an electric vehicle, wherein the main power battery pack and the backup power battery pack are connected in parallel to the load main circuit and supply power to the load, characterized in that: The high-voltage circuit where the main power battery pack is located is provided with a main IGBT module in series, and the high-voltage circuit where the backup power battery pack is located is provided with a backup IGBT module in series; It also includes an IGBT drive module and a control module respectively matched with the main IGBT module and the standby IGBT module; The control module determines the current PWM duty cycle according to the current voltage value, current current value and / or power switching command issued by the driver of the load main circuit, and controls the on and off of the main IGBT module and the backup IGBT module with the current PWM duty cycle to realize switching between the main power battery pack and the backup power battery pack to power the load.

2. The high voltage switching control system for a dual battery pack vehicle according to claim 1, characterized in that: The high-voltage circuit where the main power battery pack is located is also provided with a main current-carrying diode in series; The high-voltage circuit where the backup power battery pack is located is also provided with a backup current-carrying diode in series.

3. The high voltage switching control system for a dual battery pack vehicle according to claim 1 or 2, characterized in that: The high-voltage circuit where the main power battery pack is located also includes a main charging branch; The high-voltage circuit where the backup power battery pack is located also includes a backup charging branch.

4. The high voltage switching control system for a dual battery pack vehicle according to claim 3, characterized in that: The main charging branch includes a main regenerative charging relay and a first main current-carrying diode which are arranged in series, and the main regenerative charging relay and the first main current-carrying diode are arranged in series and then connected in reverse parallel with the main current-carrying diode; The main charging branch further includes a second main current-passing diode which is arranged in reverse parallel with the main IGBT module.

5. The high-voltage switching control system for a dual-battery pack vehicle according to claim 3, wherein the standby charging branch comprises a standby feedback charging relay and a first standby current-carrying diode arranged in series, and the standby feedback charging relay and the first standby current-carrying diode are arranged in series and then connected in reverse parallel with the standby current-carrying diode; The standby charging branch further includes a second standby pass diode which is connected in reverse parallel to the standby IGBT module.

6. A high voltage switching control method for a dual battery pack vehicle, characterized in that: A main power battery pack and a backup power battery pack are provided, and the main power battery pack and the backup power battery pack are connected in parallel and then connected to a load main circuit to supply power to the load; A main IGBT module is arranged in series in the high-voltage circuit where the main power battery pack is located, a backup IGBT module is arranged in series in the high-voltage circuit where the backup power battery pack is located, and an IGBT drive module and a control module are arranged that are matched with the main IGBT module and the backup IGBT module respectively; The control module determines the current PWM duty cycle according to the current voltage value, current current value and / or power switching command issued by the driver of the load main circuit, and controls the on and off of the main IGBT module and the backup IGBT module with the current PWM duty cycle to realize switching between the main power battery pack and the backup power battery pack to power the load.

7. The high voltage switching control method for a dual battery pack vehicle according to claim 6, characterized in that: A main current-carrying diode is arranged in series in the high-voltage circuit where the main power battery pack is located, and a main charging branch is arranged in the high-voltage circuit where the main power battery pack is located; The main charging branch includes a main regenerative charging relay and a first main current-carrying diode which are arranged in series, and the main regenerative charging relay and the first main current-carrying diode are arranged in series and then connected in reverse parallel with the main current-carrying diode; The main charging branch also includes a second main current-carrying diode which is arranged in reverse parallel with the main IGBT module; A backup current-carrying diode is arranged in series in the high-voltage circuit where the backup power battery pack is located, and a backup charging branch is arranged in the high-voltage circuit where the backup power battery pack is located; The standby charging branch includes a standby feedback charging relay and a first standby current-carrying diode which are arranged in series, and the standby feedback charging relay and the first standby current-carrying diode are arranged in series and then connected in reverse parallel with the standby current-carrying diode; The standby charging branch further includes a second standby current-carrying diode which is arranged in reverse parallel with the standby IGBT module; When the vehicle is driving, when the voltage of the main power battery pack is lower than that of the backup power battery pack, the following process is used to control the switch from the main power battery pack to the backup power battery pack: The main IGBT module is closed, the main power battery pack supplies power to the load, the main regenerative charging relay is disconnected to turn off the vehicle regenerative mode, and the current PWM duty cycle is determined; The standby IGBT module is closed, and the on and off of the standby IGBT module is controlled according to the current PWM duty cycle determined above. When the load circuit voltage reaches the voltage value of the standby power battery pack, the standby IGBT module remains on, and the main IGBT module is disconnected, and the standby power battery pack supplies power to the load; Close the standby regenerative charging relay to start the vehicle regenerative mode.

8. The high voltage switching control method for a dual battery pack vehicle according to claim 7, characterized in that: When the vehicle is driving, when the voltage of the main power battery pack is higher than that of the backup power battery pack, the following process is used to control the switch from the main power battery pack to the backup power battery pack: The main IGBT module is closed, the main power battery pack supplies power to the load, and the main regenerative charging relay is disconnected to turn off the vehicle regenerative mode; The backup IGBT module is closed and the main IGBT module is disconnected, and the backup power battery pack supplies power to the load; Close the standby regenerative charging relay to start the vehicle regenerative mode.

9. The high voltage switching control method for a dual battery pack vehicle according to claim 7, characterized in that: When the vehicle is stopped, the main power battery pack is charged according to the following process: Controlling the on and off of the main IGBT module according to a preset PWM duty cycle to slowly increase the voltage across the capacitor; The main feedback charging relay is closed, the vehicle sends a request for charging current to the charging pile, and the charging of the main power battery pack starts.

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