Double-pack parallel power battery system for vehicle and power-on and power-off control method

Abstract

The invention discloses a double-pack parallel power battery system for a vehicle and a power-on and power-off control method. The parallel connection result of the two power battery packs with the same appearance is used as the battery core of the double-pack parallel connection power battery system, the first power battery pack and the second power battery pack are identified through the double-pack parallel connection ID, and when the voltage difference between the two battery packs is within a certain range, double-pack parallel connection simultaneous power-on can be achieved; if the voltage difference between the two battery packs is out of a certain range, the main pack with the high voltage enters the whole vehicle system to discharge independently, and when the main pack is discharged to the required range of the voltage difference between the two battery packs, the main pack enters the discharging process at the same time. The problem that the pressure difference between the two battery packs is too large is solved, independent operation of the single battery pack can be achieved, better environmental adaptability is achieved, and the driving experience is improved.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, specifically to a dual-pack parallel power battery system for vehicles and a power-on / off control method. Background Technology

[0002] Traditional gasoline-powered all-terrain vehicles (ATVs), as special vehicles integrating practicality, entertainment, and sports, are mainly used for long-distance expeditions and multi-day treks, heavy-duty agricultural / forestry operations, professional hunting, and fieldwork. While their long range, reliability, and adaptability to extreme environments are irreplaceable, the engines of traditional gasoline-powered ATVs emit pollutants such as carbon monoxide, hydrocarbons, nitrogen oxides, and lead during operation, causing air and soil pollution in the local environment. Furthermore, the engine noise not only disrupts the natural tranquility but also affects the quality of life of nearby residents. Therefore, with the development of environmental protection and new energy concepts, the electrification of traditional ATVs has become a trend. Currently, pure electric ATVs on the market generally use lead-acid batteries or low-capacity, naturally cooled lithium batteries.

[0003] Pure electric all-terrain vehicles have advantages such as zero emissions during operation (completely no exhaust emissions), extremely low noise, high torque in real time (strong starting, climbing, and getting out of trouble), low use and maintenance costs, and high degree of intelligent integration. However, pure electric all-terrain vehicles usually have range anxiety issues, such as a full-charge range of 60-120km and frequent charging.

[0004] Therefore, effectively managing the charging and discharging of the vehicle's power battery system to meet customer needs, possessing large capacity, high density, long range, short charging time, long service life, and no pollution, while also meeting the power requirements for driving on various complex road surfaces such as beaches, grasslands, mountain roads, and tourist destinations, has become a challenge. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-pack parallel power battery system for vehicles and a power-on / off control method. The system uses BMS within the two battery packs to independently monitor various parameters such as battery voltage, current, and temperature, and control them with high-voltage relays. This allows both batteries to work simultaneously, or a single battery pack to work independently.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A dual-pack parallel power battery system for vehicles includes the following steps: a first power battery pack, a second power battery pack, an on-board charger (OBC), a vehicle controller (VCU), a motor controller (MCU), and a motor. The high-voltage positive and high-voltage negative terminals of the first and second power battery packs are both connected to the on-board charger (OBC), achieving a physical parallel connection within the OBC. The vehicle controller (VCU) communicates with both the motor controller (MCU) and the OBC, and the MCU is connected to the motor. In this dual-pack parallel power battery system, the high-voltage positive (HV+) and high-voltage negative (HV-) terminals of the first and second power battery packs are physically connected in parallel within the OBC to enable simultaneous charging and discharging control of both battery packs.

[0007] Both the first and second power battery packs are equipped with a battery management system (BMS), a cooling system, an electrical system, and functional accessories. The BMS is used to monitor the cell status of the battery pack in real time and communicate with the vehicle control unit (VCU). The pre-charge relay, main positive relay, and main negative relay are used to control the connection and disconnection of the battery pack to achieve safe start-stop. The electrical system includes the pre-charge relay, main positive relay, and main negative relay.

[0008] The first and second power battery packs are equipped with a dual-pack parallel ID pin at their low-voltage communication interface. This ID pin and related circuitry identify the first and second power battery packs, providing feasibility for the dual-pack parallel design and power-on / off control. Simultaneously, the battery management system (BMS) within both the first and second power battery packs can independently monitor the cell voltage, current, and temperature in real time, as follows: The BMS can adjust the charging and discharging current and voltage based on the monitored state of charge and discharge of the battery to ensure that the battery system operates within the appropriate range. The BMS can adjust the operation of the cooling system based on the temperature of the cells inside the battery pack to prevent overheating or overcooling. BMS can monitor various parameters in the battery pack in real time, such as voltage, current, and temperature, and issue alarms when abnormalities occur so that timely repairs or replacements can be carried out. The BMS can communicate with the VCU and OBC through the low-voltage communication interface of the battery pack to achieve centralized management and control of the low battery system.

[0009] According to the above technical solution, the charging power of the on-board charger (OBC) is greater than or equal to twice the charging power of the on-board charger (OBC) in a single-pack power battery system.

[0010] Without changing the original power battery pack, a new power battery pack can be connected in parallel. If the original OBC charging power is 3.3kW, then after connecting a new power battery pack in parallel, the OBC charging power will be adjusted to 6.6kW. This not only doubles the capacity of the vehicle's power battery system, but also keeps the charging time basically unchanged.

[0011] Another technical solution is a power-on / off control method for a dual-pack parallel power battery system for vehicles, including power-on of the dual-pack parallel power battery system, normal power-off of the dual-pack parallel power battery system, and emergency power-off of the dual-pack parallel power battery system.

[0012] According to the above technical solution, the power-on steps of the dual-pack parallel power battery system include: The vehicle control unit (VCU) is awakened. After starting, it sends a CAN message requesting the high-voltage interlock HVIL circuit hard wire and low-voltage relay. At the same time, it monitors the status of the high-voltage interlock HVIL circuit and wakes up the battery management system (BMS) of the first and / or second power battery packs. After the battery management system (BMS) of the first power battery pack and / or the second power battery pack is woken up, it performs a self-test operation to monitor the status of the high-voltage interlock HVIL circuit and confirm whether the insulation status is normal. If the battery management system (BMS) of the first and second power battery packs is fault-free, the current B+ voltage of the first / second power battery pack is determined: If the current B+ voltage difference of the first power battery pack / second power battery pack is greater than the threshold A, the first power battery pack enters the discharge process state and at the same time reports a fault in the second power battery pack. When the current B+ voltage difference of the first power battery pack / second power battery pack is less than or equal to the threshold A, the first power battery pack / second power battery pack simultaneously enters the discharge process.

[0013] The dual-pack parallel power battery system identifies the first and second power battery packs via a dual-pack parallel ID. When the voltage difference between the two battery packs is within a certain range, both packs can be powered on simultaneously in parallel. If the voltage difference exceeds this range, the battery pack with the higher voltage will discharge independently, powering the entire vehicle system. Once the voltage difference between the two packs falls within the required range, they will simultaneously resume the discharge process. This dual-pack parallel design not only solves the problem of excessive voltage difference between the two battery packs but also allows each pack to operate independently, giving pure electric all-terrain vehicles better environmental adaptability and greatly satisfying customers' demands for a better driving experience.

[0014] According to the above technical solution, if the second power battery pack fails during the power-on process of the dual-pack parallel power battery system, the second power battery pack will reduce its high voltage and report the fault, while the first power battery pack will continue to enter the discharge process. If the first power battery pack malfunctions, both the first power battery pack and the second power battery pack will be subjected to high voltage simultaneously.

[0015] According to the above technical solution, the normal power-down steps of the dual-pack parallel power battery system include: When the key signal is detected to be stopped, the vehicle control unit (VCU) immediately requests the DC / DC module in the on-board charger (OBC) and the motor controller (MCU) module to leave the working mode. The vehicle control unit (VCU) then requests the battery management system (BMS) of the first / second power battery pack to disconnect the main positive relay / main negative relay. After the battery management system (BMS) of the first power battery pack / second power battery pack completes the power-down response, the vehicle controller (VCU) disconnects the HVIL circuit and the low-voltage relay, and each node enters the power-down sleep state.

[0016] According to the above technical solution, during the normal power-down process of the dual-pack parallel power battery system, when the battery management system (BMS) of the first power battery pack / second power battery pack receives the power-down command from the vehicle controller (VCU), if the bus current is less than the safe current, it will disconnect the main positive relay and the main negative relay in sequence, and then judge the bus voltage. When the voltage drops to a preset value, the battery management system (BMS) of the first power battery pack / second power battery pack will feed back the power-down command to the vehicle controller (VCU) and enter the power-down Afterrun state. At the same time, after the battery management system (BMS) of the first power battery pack / second power battery pack sends the power-down command, it will automatically enter the sleep state after the sleep conditions are met.

[0017] The Afterrun state is a transitional state in which the vehicle or ECU (electronic control unit) maintains a short power supply after ignition / high voltage power-off to complete necessary follow-up work before entering hibernation or being completely powered off.

[0018] According to the above technical solution, the emergency power-off steps of the dual-pack parallel power battery system include: Under normal high-voltage power-on operation of the vehicle, when an emergency high-voltage failure occurs, the vehicle controller (VCU) requests the motor controller (MCU) to set the torque to 0. When the vehicle speed is less than or equal to threshold B, the VCU commands the parking system to brake and stop. Subsequently, it commands the DC / DC module in the on-board charger (OBC) to power down, and then commands the battery management system (BMS) of the first / second power battery pack to disconnect the high-voltage connection. The BMS of the first / second power battery pack sequentially disconnects the main positive contactor and the main negative contactor. Then, it commands the vehicle controller (MCU) to perform active discharge. The vehicle controller (MCU) discharges the bus voltage to below voltage M within ts. The VCU sends a shutdown power-down command to each controller and disconnects the hard-wired high-level wake-up.

[0019] The shutdown command is a control command issued by the vehicle control system (such as VCU, BCM, or engine ECU) to terminate the operation of the equipment / system and enter a power-off or hibernation state. It is the core signal for realizing the orderly switching of the vehicle from the running state to the power-off state.

[0020] Including a technical solution, the present invention further provides an electronic device, comprising: one or more processors; and a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to execute the power-on / off control method for a dual-pack parallel power battery system for vehicles as described in any of the above technical solutions.

[0021] Including a technical solution, the present invention further provides a storage medium storing at least one instruction, which is loaded and executed by a processor to implement the power-on / off control method for a dual-pack parallel power battery system for vehicles as described in any of the above technical solutions.

[0022] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: The dual-pack parallel power battery system of this invention adopts two identical battery packs with built-in BMS, achieving high-voltage parallel connection within an external OBC. Because the two battery packs use the same design, the commonality of components is greatly improved, significantly reducing production and management costs. Simultaneously, the BMS within each battery pack allows for independent monitoring of various parameters such as battery voltage, current, and temperature, as well as high-voltage relay control. This enables simultaneous operation of both batteries or independent operation of a single battery pack, significantly improving the environmental adaptability of pure electric all-terrain vehicles and meeting users' requirements for long driving range on various complex road surfaces such as beaches, grasslands, mountain roads, and tourist destinations. Furthermore, it solves both the environmental pollution problems of traditional internal combustion engine all-terrain vehicles and the range anxiety caused by the low capacity of single battery packs. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a vehicle layout diagram of a dual-pack parallel power battery system for vehicles according to the present invention; Figure 2 This is a diagram of the battery pack in a dual-pack parallel power battery system. Figure 3 This is an electrical schematic diagram of a dual-pack parallel power battery system as an example. Figure 4This is a flowchart illustrating the power-on process of a dual-pack parallel power battery system in an embodiment. Figure 5 This is a flowchart illustrating the normal power-down process of a dual-pack parallel power battery system in an embodiment. Figure 6 This is a flowchart illustrating the emergency power-off process of a dual-pack parallel power battery system in an embodiment. Detailed Implementation

[0024] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: A dual-pack parallel power battery system for vehicles includes: a first power battery pack, a second power battery pack, an on-board charger (OBC), a vehicle controller (VCU), a motor controller (MCU), and a motor. The high-voltage positive and negative terminals of both the first and second power battery packs are connected to the OBC, achieving a physical parallel connection within the OBC. The VCU communicates with both the MCU and the OBC, and the MCU is connected to the motor. By adding another power battery pack in parallel without altering the original battery pack, and by adjusting the OBC charging power from 3.3kW to 6.6kW, the overall vehicle power battery system capacity is doubled while maintaining a relatively constant charging time.

[0026] Among them, the first power battery pack 2 and the second power battery pack 3 are the core battery units of a dual-pack parallel power battery system for vehicles. They are fixed to the vehicle frame 1 through their respective mounting points 9, and are arranged as a whole under the front and rear seats of the vehicle. Figure 1 As shown. The bottom of the battery pack has a pre-drilled lifting hole 10 for lifting operations during installation and maintenance.

[0027] Battery pack outline diagram as follows Figure 2 As shown, both the first power battery pack 2 and the second power battery pack 3 are equipped with a battery management system (BMS), a cooling system, an electrical system, and functional accessories.

[0028] Cooling system: The inlet 5 of the first power battery pack 2 or the second power battery pack 3 is connected to the vehicle cooling pipeline. After the coolant enters the battery pack and completes heat exchange, it flows back to the vehicle cooling circuit through the outlet 6, thereby maintaining the battery in a suitable temperature range.

[0029] Electrical system connections: High-voltage circuit: The first power battery pack 2 and the second power battery pack 3 adopt a dual-pack parallel design. The two are connected in parallel through their respective high-voltage connectors 7 to provide high-voltage DC power to the whole vehicle.

[0030] Low-voltage circuit: The low-voltage connector 8 of the first power battery pack 2 and the second power battery pack 3 is responsible for connecting the battery management system (BMS) and the vehicle controller, and is used to transmit battery status monitoring signals such as temperature, voltage and current, as well as receive control commands from the vehicle.

[0031] The explosion-proof valve 4 installed on the top of the battery pack is a passive safety device. When thermal runaway, high pressure or high temperature occur inside the battery pack, the explosion-proof valve will open to release the internal pressure and prevent the battery pack from undergoing violent deformation or explosion.

[0032] The electrical schematic diagram of the dual-pack parallel power battery system is as follows: Figure 3 As shown, the dual-pack parallel power battery system consists of a first power battery pack 2 and a second power battery pack 3. Both the first power battery pack 2 and the second power battery pack 3 are equipped with a battery management system (BMS), a pre-charge relay, a main positive relay, a main negative relay, and current sensors. In the dual-pack parallel power battery system, the HV+ and HV- of the main and auxiliary packs are physically connected in parallel within the OBC (On-Board Charger) to enable simultaneous charging and discharging control of both battery packs.

[0033] Example 2: Power-on steps for a dual-pack parallel power battery system are as follows Figure 4 : The vehicle control unit (VCU) is woken up (by key, network, or hard-wired charging CC signal). After startup, it sends a CAN message requesting the high-voltage interlock HVIL circuit hard-wired and the 12V low-voltage relay. At the same time, it monitors the status of the high-voltage interlock HVIL circuit and wakes up the battery management system (BMS) of the first and / or second power battery packs (the CU sends a network management CAN message or KL_30 signal to wake up). After the battery management system (BMS) of the first and / or second power battery packs is woken up, it performs a self-test operation, monitors the status of the high-voltage interlock HVIL circuit, and confirms whether the insulation status is normal. If the battery management system (BMS) of the first and second power battery packs is fault-free, the current B+ voltage of the first / second power battery pack is determined: If the current B+ voltage difference between the first power battery pack and the second power battery pack is greater than 5V, the first power battery pack enters the discharge process state and reports a fault in the second power battery pack at the same time. When the current B+ voltage difference of the first power battery pack / second power battery pack is less than or equal to 5V, the first power battery pack / second power battery pack simultaneously enters the discharge process.

[0034] If a Level 4 fault occurs in the second power battery pack during the power-on process of the dual-pack parallel power battery system, the second power battery pack will reduce its high voltage and report the fault, while the first power battery pack will continue to enter the discharge process. If the first power battery pack experiences a level 4 fault, both the first and second power battery packs will be subjected to high voltage simultaneously.

[0035] Example 3: Normal power-down procedure for a dual-pack parallel power battery system ( Figure 5 )include: Upon detecting that the key signal has stopped, the Vehicle Control Unit (VCU) immediately requests the DC / DC module and MCU module within the Onboard Battery (OBC) to exit operating mode. Then, the VCU requests the Battery Management System (BMS) of the first / second battery pack to disconnect the main positive / negative relays. After the BMS completes its power-down response, the VCU disconnects the HVIL circuit and the low-voltage relay, and all nodes enter a power-down sleep state.

[0036] When the BMS receives a power-down command from the VCU, if the bus current is less than the safe current, it will sequentially disconnect the main positive relay and the main negative relay. Then, it will check the bus voltage; when the voltage drops to a preset value, the BMS will send a power-down command back to the VCU and enter the power-down Afterrun state. Simultaneously, after sending the power-down command, the BMS will automatically enter sleep mode if the sleep conditions are met.

[0037] Example 4: Emergency power-off procedure for a dual-pack parallel power battery system ( Figure 6 )include: Under normal high-voltage power-on operation, when an emergency high-voltage failure occurs in the vehicle, battery system, drive system, or high-voltage components, the vehicle controller (VCU) requests zero torque from the motor controller (MCU). At a vehicle speed ≤2 km / h, the VCU commands the EPB parking system to brake and stop the vehicle. Subsequently, it commands the DC / DC converter to power down, then commands the BMS of the first / second battery pack to disconnect the high-voltage connection. The BMS sequentially disconnects the main positive and negative contactors, and then commands the MCU to perform active discharge. The MCU discharges the bus voltage to below 60V within 3 seconds. Finally, the VCU sends a shutdown command to each controller and disconnects the hard-wired high-level wake-up signal.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-pack parallel power battery system for vehicles, characterized in that, include: The system consists of a first power battery pack, a second power battery pack, an on-board charger (OBC), a vehicle controller (VCU), a motor controller (MCU), and a motor. The high-voltage positive and high-voltage negative terminals of the first and second power battery packs are both connected to the on-board charger (OBC), and are physically connected in parallel inside the OBC; the vehicle controller (VCU) communicates with the motor controller (MCU) and the OBC respectively, and the motor controller (MCU) is connected to the motor; Both the first and second power battery packs are equipped with a battery management system (BMS), a cooling system, an electrical system, and functional accessories. The battery management system (BMS) is used to monitor the cell status of the battery pack in real time and communicate with the vehicle control unit (VCU).

2. The dual-pack parallel power battery system for vehicles according to claim 1, characterized in that, The charging power of the on-board charger (OBC) is greater than or equal to twice the charging power of the on-board charger (OBC) in a single-pack power battery system.

3. A method for controlling the power-on and power-off of a dual-pack parallel power battery system for vehicles, characterized in that, This includes powering on the dual-pack parallel power battery system, normal powering off the dual-pack parallel power battery system, and emergency powering off the dual-pack parallel power battery system.

4. The power-on / off control method for a dual-pack parallel power battery system for vehicles according to claim 3, characterized in that, The power-on steps for the dual-pack parallel power battery system include: The vehicle control unit (VCU) is awakened. After starting, it sends a CAN message requesting the high-voltage interlock HVIL circuit hard wire and low-voltage relay. At the same time, it monitors the status of the high-voltage interlock HVIL circuit and wakes up the battery management system (BMS) of the first and / or second power battery packs. After the battery management system (BMS) of the first power battery pack and / or the second power battery pack is woken up, it performs a self-test operation to monitor the status of the high-voltage interlock HVIL circuit and confirm whether the insulation status is normal. If the battery management system (BMS) of the first and second power battery packs is fault-free, the current B+ voltage of the first / second power battery pack is determined: If the current B+ voltage difference of the first power battery pack / second power battery pack is greater than the threshold A, the first power battery pack enters the discharge process state and at the same time reports a fault in the second power battery pack. When the current B+ voltage difference of the first power battery pack / second power battery pack is less than or equal to the threshold A, the first power battery pack / second power battery pack simultaneously enters the discharge process.

5. The power-on / off control method for a dual-pack parallel power battery system for vehicles according to claim 4, characterized in that, If the second power battery pack fails during the power-on process of the dual-pack parallel power battery system, the second power battery pack will reduce its high voltage and report the fault, while the first power battery pack will continue to enter the discharge process. If the first power battery pack malfunctions, both the first power battery pack and the second power battery pack will be subjected to high voltage simultaneously.

6. The power-on / off control method for a dual-pack parallel power battery system for vehicles according to claim 5, characterized in that, The normal power-down procedure for the dual-pack parallel power battery system includes: When the key signal is detected to be stopped, the vehicle control unit (VCU) immediately requests the DC / DC module in the on-board charger (OBC) and the motor controller (MCU) module to leave the working mode. The vehicle control unit (VCU) then requests the battery management system (BMS) of the first / second power battery pack to disconnect the main positive relay / main negative relay. After the battery management system (BMS) of the first power battery pack / second power battery pack completes the power-down response, the vehicle controller (VCU) disconnects the HVIL circuit and the low-voltage relay, and each node enters the power-down sleep state.

7. The power-on / off control method for a dual-pack parallel power battery system for vehicles according to claim 6, characterized in that, During the normal power-down process of the dual-pack parallel power battery system, when the battery management system (BMS) of the first power battery pack / second power battery pack receives the power-down command from the vehicle controller (VCU), if the bus current is less than the safe current, it will disconnect the main positive relay and the main negative relay in sequence, and then judge the bus voltage. When the voltage drops to a preset value, the battery management system (BMS) of the first power battery pack / second power battery pack will feed back the power-down command to the vehicle controller (VCU) and enter the power-down Afterrun state. At the same time, after the battery management system (BMS) of the first power battery pack / second power battery pack sends the power-down command, it will automatically enter the sleep state after the sleep conditions are met.

8. The power-on / off control method for a dual-pack parallel power battery system for vehicles according to claim 7, characterized in that, The emergency power-off steps for the dual-pack parallel power battery system include: Under normal high-voltage power-on operation of the vehicle, when an emergency high-voltage failure occurs, the vehicle controller (VCU) requests the motor controller (MCU) to set the torque to 0. When the vehicle speed is less than or equal to threshold B, the VCU commands the parking system to brake and stop. Subsequently, it commands the DC / DC module in the on-board charger (OBC) to power down, and then commands the battery management system (BMS) of the first / second power battery pack to disconnect the high-voltage connection. The BMS of the first / second power battery pack sequentially disconnects the main positive contactor and the main negative contactor. Then, it commands the vehicle controller (MCU) to perform active discharge. The vehicle controller (MCU) discharges the bus voltage to below voltage M within ts. The VCU sends a shutdown power-down command to each controller and disconnects the hard-wired high-level wake-up.

9. An electronic device, characterized in that, include: One or more processors; A storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to perform the method according to any one of claims 3-8.

10. A storage medium, characterized in that, The storage medium stores at least one instruction, which is loaded and executed by a processor to implement the method as described in any one of claims 3-8.

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