Heavy electric vehicle high-voltage power distribution system and control method

Abstract

The invention relates to the technical field of vehicle control, and discloses a heavy electric vehicle high-voltage power distribution system and a control method. The battery power distribution unit is integrated with a high-voltage main loop on-off module, a centralized pre-charging module and a short-circuit protection module, and is used for centralized on-off control and centralized pre-charging management of high-voltage electric energy; the charging interface is used for external charging; the power electronic unit is integrated with a motor controller, a direct-current converter, an auxiliary system controller and a power distribution module and forms a plurality of high-voltage power utilization loops, and high-voltage electric energy transmitted by the integrated battery power distribution unit is distributed to the high-voltage power utilization loops; the motor controller is configured to actively discharge the high-voltage electric loop; the power distribution system and the high-voltage electric appliance are cooperatively controlled through a whole vehicle CAN network. According to the invention, system architecture hardware simplification is realized by optimizing a whole vehicle CAN network communication mechanism and a whole vehicle high-voltage control strategy, and the reliability and safety of a high-voltage power distribution system are improved through a control mode of centralized pre-charging and sequential enabling of electric appliances.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to a heavy electric vehicle high-voltage power distribution system and a control method. BACKGROUND

[0002] The current heavy truck high-voltage power distribution system generally adopts a decentralized power distribution architecture in which each high-voltage accessory load (such as an electric air conditioner compressor EAC, a positive temperature coefficient heater PTC, a vehicle-mounted power supply SDCAC, and a DCDC converter) is independently configured with a high-voltage relay.

[0003] When the above architecture is used, there are problems: after the whole vehicle high-voltage power is turned on, only the MCU and the DCDC are in the high-voltage power supply state by default, and the remaining accessory loops are in the high-voltage power-off state, which needs to rely on the VCU to enable the PDU to close the corresponding relay to be powered on. Since each accessory loop does not integrate a pre-charge loop, and the internal power module usually contains a large capacitive load, a sharp inrush current will be generated at the moment of direct closure of the relay, which can easily cause electric arc, contact welding, or even permanent sticking of the relay, seriously threatening the system reliability. At the same time, due to the lack of a unified pre-charge and power-off management mechanism, when the main drive high-voltage loop is cut off, some accessory loops may still have residual high-voltage bus, forming a risk of electric shock or secondary short circuit. In addition, this scheme separately configures a high-voltage relay, a drive circuit, and a control signal interface for each load, which not only significantly increases the hardware cost, but also leads to complex system wiring, numerous control nodes, strong communication dependency, and rising failure rate, making it difficult to meet the comprehensive technical needs of heavy truck platforms for high-voltage power distribution systems in terms of safety, integration, reliability, and cost control. SUMMARY

[0004] The present application aims to provide a heavy electric vehicle high-voltage power distribution system and a control method, which optimizes the whole vehicle CAN network communication mechanism and the whole vehicle high-voltage control strategy, simplifies the hardware of the high-voltage power distribution architecture, reduces the hardware cost and the number of system nodes, enables the control of the electric appliances in sequence through centralized pre-charging, improves the control reliability and fault predictability of the nodes through CAN networking, and effectively improves the overall safety of the high-voltage system.

[0005] The basic scheme provided by the present application is: a heavy electric vehicle high-voltage power distribution system, comprising: a battery system outputting high-voltage direct current; an integrated battery power distribution unit connected with the total positive and total negative bus of the battery system, integrating a high-voltage main loop on-off module, a centralized pre-charge loop, and a short-circuit protection module, for centralized on-off control of high-voltage electric energy and centralized pre-charge management of all high-voltage electric loops; a charging interface connected with the integrated battery power distribution unit through a charging bus, for external charging; The integrated power electronic unit is connected with the integrated battery distribution unit through a main loop bus, and is integrated with a motor controller, a direct current converter, an auxiliary system controller and a distribution module, and forms a plurality of high-voltage electrical circuits by connecting corresponding high-voltage electrical appliances respectively, and the high-voltage electrical energy transmitted by the integrated battery distribution unit is distributed to each high-voltage electrical circuit through the distribution logic integrated in the integrated power electronic unit, wherein the motor controller is configured to actively discharge the high-voltage electrical circuit. The distribution system and the high-voltage electrical appliance perform at least power-on and fault detection control through the vehicle CAN network.

[0006] The application also provides a high-voltage distribution control method for a heavy electric vehicle, which utilizes a high-voltage distribution system for a heavy electric vehicle. After the power-on wake-up condition is met, the vehicle controller sends a high-voltage-on instruction. The battery management system closes the main negative relay and the main positive pre-charging relay in sequence according to the preset condition to start centralized pre-charging of the high-voltage electrical circuit, closes the main positive relay after pre-charging is successfully judged, disconnects the pre-charging relay, and reports the high-voltage-on completion state to the vehicle controller after success. The vehicle controller confirms the high-voltage-on completion, and enables the direct current converter and the high-voltage electrical appliance in sequence through the vehicle CAN network. The vehicle controller detects that the vehicle meets the condition and sends a drivable state, and the high-voltage power-on process is completed.

[0007] The working principle and advantages of the application are as follows: The high-voltage distribution system architecture is highly integrated, and the dispersed high-voltage components are integrated into a centralized high-voltage distribution system through the two-stage distribution integrated architecture of the integrated battery distribution unit BDU and the integrated power electronic unit PEU, replacing the traditional dispersed distribution mode, the BDU centrally realizes high-voltage on-off and distribution on the battery side and the charging side, only three relays and two fuses are configured, the PEU centrally integrates power control, low-voltage conversion and auxiliary distribution functions, greatly reduces the number of dispersed components and redundant lines, reduces system complexity, and improves system reliability.

[0008] The BDU is integrated with a centralized pre-charging circuit, which pre-charges the capacitive load of all high-voltage electrical circuits (MCU, DCDC, auxiliary system, etc.) in the PEU when the vehicle is powered on, avoids the instantaneous large current caused by the closure of the main relay, and eliminates the need for independent pre-charging circuits in each sub-module, thereby reducing costs.

[0009] With a charging and discharging compatible design, the BDU supports both "battery discharge (driving the vehicle)" and "external charging (CS1 / CS2)" functions, enabling bidirectional energy management.

[0010] By adopting a multi-load power distribution strategy, the power distribution in the PEU can be realized in multiple scenarios, including "power drive (MCU + motor), low-voltage power supply (DCDC + 24V battery), and auxiliary system (SDCAC, PDU + various loads)," to meet the complex power needs of heavy-duty electric vehicles.

[0011] CAN networking enhances the control reliability and fault prediction capabilities of nodes. The BDU, PEU, and various submodules achieve command interaction and status synchronization via the CAN network. Optimized using the vehicle's CAN network, all high-voltage electrical circuits are powered on via a high-voltage pre-charge circuit when the vehicle is powered on, preventing capacitive loads in high-voltage circuits from causing relay sticking. This enables coordinated operation of various components, increasing system reliability and maintainability. Active discharge functionality is implemented by MCU1 / MCU2 within the PEU. When the system is powered off, the characteristics of the drive motor windings are used to release residual energy in the high-voltage circuits, improving safety.

[0012] This invention simplifies hardware through optimization of the CAN network and vehicle control strategy, effectively reducing the complexity of the high-voltage power distribution system in electric heavy-duty trucks, minimizing the use of high-voltage relays, and avoiding the increased system cost of reusing pre-charge circuits. It also simplifies system nodes and improves system reliability and maintainability. The system retains the fast-charging relay while merging the main and negative relays to comply with GB / T 20234.3-2011 requirements. Based on this optimization, the vehicle meets the requirements of GB / T 18384-2020 collision safety and GB / T 38031-2020 battery mandatory testing, demonstrating significant market application value. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a high-voltage power distribution system for a heavy-duty electric vehicle provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the high-voltage power-on process provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the high-voltage power-down process provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the charging process provided in an embodiment of the present invention. Detailed Implementation

[0014] The following detailed explanation illustrates the specific implementation methods: The basic implementation examples are as follows: Figure 1 As shown: A high-voltage power distribution system for heavy-duty electric vehicles, comprising: The battery system outputs high-voltage direct current. The integrated battery distribution unit (BDU) is connected to the main positive and main negative busbars of the battery system. It integrates a high-voltage main circuit switching module, a centralized pre-charge circuit and a short-circuit protection module, and is used for centralized switching control of high-voltage power, centralized pre-charge management and active discharge management of all high-voltage power circuits. The charging interfaces (CS1, CS2) are connected to the integrated battery distribution unit (BDU) via a charging bus for external charging. The integrated power electronic unit (PEU) is connected to the integrated battery distribution unit (BDU) via the main circuit bus. It integrates a motor controller (MCU), a DC-DC converter (DCDC), an auxiliary system controller (SDCAC), and a power distribution module (PDU). It forms multiple high-voltage power circuits by connecting to corresponding high-voltage electrical appliances. Through the power distribution logic integrated within the integrated power electronic unit (PEU), the high-voltage power delivered by the integrated battery distribution unit (BDU) is distributed to each high-voltage power circuit. The motor controller (MCU) is configured to actively discharge the high-voltage circuits. The power distribution system and high-voltage electrical appliances are controlled via the vehicle's CAN network for at least power-on / off and fault detection.

[0015] Specifically: This high-voltage power distribution system adopts a core architecture consisting of a battery system, BDU, PEU, and high-voltage loads, and works in conjunction with a charging interface to achieve complete high-voltage energy storage, distribution, use, and replenishment functions. The core components and their connections are as follows: Battery system: Composed of multiple battery boxes (battery box 1, battery box 2, battery box 3, and battery box 4), providing high-voltage DC power to the system. Power is output through the main positive and main negative busbars, with a busbar specification of 70mm². 2 It can adapt to different current requirements.

[0016] BDU: The high-voltage power distribution hub of the system, connecting the battery system, charging interface, and PEU, realizing power distribution, on / off control, and fault protection between the battery and other high-voltage components. The high-voltage main circuit switching module of the BDU includes one main positive relay, one main negative relay, and one main positive pre-charge relay. The centralized pre-charge circuit consists of the main positive pre-charge relay and one pre-charge resistor connected in series. All high-voltage power circuits are pre-charged through the single centralized pre-charge circuit in the BDU, eliminating the need to configure pre-charge relays and corresponding fuses for each high-voltage submodule. This eliminates the need for separate pre-charge relays and corresponding fuses for each high-voltage submodule, reducing the number of components and system cost while eliminating relay sticking caused by capacitive loads. The short-circuit protection module includes two manual maintenance switches (MSDs) with built-in fuses, which control two branches respectively. The two branches are connected in parallel and then in series at the front end of the battery's main positive bus entering the BDU. This is the ultimate protection for the high-voltage main circuit, used to deal with extreme faults such as overcurrent and short circuit in the main circuit, and quickly blows the fuse to cut off the circuit. It also includes a charging circuit fuse, which is connected in series in the branch connecting the CS1 / CS2 charging interface and the BDU. This protects the charging circuit separately and prevents overcurrent damage to the battery or BDU during charging. There are no other redundant fuses (such as collision-specific fuses). The structure is optimized and simplified through control strategies.

[0017] Charging interfaces: Includes two charging interfaces, CS1 and CS2, connected via positive and negative charging buses (both can use 70mm). 2 It connects to the BDU to enable external charging equipment to replenish the battery system, thus realizing the high-voltage charging function of the vehicle.

[0018] PEU: The core of high-voltage power control, integrating five sub-modules: MCU1 (motor controller 1), MCU2 (motor controller 2), DCDC (DC converter), SDCAC (auxiliary system controller), and PDU (power distribution module), responsible for converting and distributing high-voltage power to various loads.

[0019] High-voltage electrical appliances include drive motors (TM1, TM2), 24V batteries, PM (auxiliary motors, such as air conditioning compressors), PTCC (coolant heaters), PTB1 / PTB2 (pumps, such as air compressors), ACCM (other auxiliary components), etc., covering power drive, low-voltage power supply and auxiliary function requirements.

[0020] The above core components are connected to form the following circuit: 1) Main power supply circuit: Battery → BDU → PEU → Drive load The battery system is connected to the BDU via the "Battery Total Positive" and "Battery Total Negative" buses. After being controlled by the internal on / off circuit of the BDU, the battery power is transmitted to the PEU via the "Main Circuit Positive" and "Main Circuit Negative" buses. Bus specifications can be found in [reference needed]. Figure 1 Data design, such as the total positive 1 of the battery using a 70mm diameter. 2 .

[0021] After receiving high-voltage electrical energy, the PEU drives TM1 and TM2 (drive motors) respectively through MCU1 and MCU2 to provide power to the vehicle; at the same time, it converts the high-voltage DC power to low-voltage DC power through DCDC to charge the 24V battery and ensure the operation of the low-voltage system.

[0022] 2) Charging circuit: Charging interface → BDU → Battery system External charging devices are connected via the CS1 or CS2 interface and transmitted to the BDU via the "charging positive" and "charging negative" buses. The BDU controls the input of charging energy into the battery system to replenish the battery.

[0023] 3) Auxiliary power supply circuit: PEU → Auxiliary load The SDCAC inside the PEU drives the PM (auxiliary motor), and the PDU (power distribution module) distributes electrical energy to the PTCC (coolant heater), PTB1 / PTB2 (pump components), and ACCM (other auxiliary components) to meet the power needs of auxiliary functions such as vehicle air conditioning, thermal management, and brake assist.

[0024] Based on the aforementioned high-voltage power distribution system for heavy-duty electric vehicles, this embodiment also provides a control method for the high-voltage power distribution system for heavy-duty electric vehicles; the method includes a power-on strategy, such as... Figure 2 As shown: The entire process from vehicle wake-up to stable power supply to the high-voltage system is essentially "safety verification → pre-charging → main circuit closure".

[0025] Upon receiving the vehicle power-on signal, the Vehicle Control Unit (VCU) wakes up each high-voltage node via hard-wired low-voltage control. If each high-voltage node performs a self-test without faults and the Battery Management System (BMS) allows discharge, the VCU sends a high-voltage power-on command. The BMS then closes the main negative relay and the main positive pre-charge relay according to preset conditions to initiate centralized pre-charging of the high-voltage power circuit. If pre-charging is successful, the main positive relay closes and the pre-charge relay opens. Upon successful pre-charging, the BMS reports the high-voltage power-on completion status to the VCU. Once the VCU confirms high-voltage power-on completion, it sequentially enables the DC-DC converter and high-voltage electrical components via the vehicle's CAN network. When conditions such as no charging signal, neutral gear, and normal brake air pressure are met, the VCU sends a "Ready" status, completing the high-voltage power-on process.

[0026] The specific procedure for applying high voltage is as follows: Wake-up and initialization phase: 1) The VCU (Vehicle Controller) receives the vehicle power-on signal (keyon wake-up signal), performs low-voltage power-on, and wakes up all high-voltage nodes, including BDU, PEU, and BMS (Battery Management System), through hard-wired low-voltage. At this time, the VCU must ensure that the high-voltage components (high-voltage electrical appliances) are disabled before the BMS main circuit relay is closed. 2) Each high-voltage node (BDU, PEU, BMS) performs a self-test and reports its status to the VCU after confirming there are no faults. The self-test items include (the following items must be met simultaneously): summary data collection (voltage, SOC, temperature); whether each high-voltage relay is disconnected and fault-free; no high-voltage interlock faults; no faults in the fault list that are not allowed to apply high voltage to the system. 3) The BMS completes battery status detection and allows discharge, then feeds back the discharge permission signal to the VCU; 4) After the VCU confirms that all self-tests have passed and the BMS allows discharge, it sends a high-voltage command to the BMS and enters the pre-charge preparation state.

[0027] Centralized pre-charging and main circuit closure stage (core) 5) After the BMS receives the high voltage command and continues for the first preset time (e.g., 300ms), it closes the main negative relay, then closes the pre-charge relay to start the centralized pre-charge of the high voltage power circuit and judges whether the pre-charge is successful. 6) After the pre-charge judgment is successful, and the voltage at the rear end of the main positive relay is detected, if the voltage difference between the front and rear ends of the main positive relay is less than 20V, close the main positive relay; 7) After the main positive relay closes and remains closed for a second preset time (e.g., 100ms), the BMS disconnects the precharge relay and reports the high-voltage completion status (status code: 0x2: HV closed) to the VCU. The BMS sends the current high-voltage status to the vehicle's BMS: ID: 0x1883EFF3; Bit: 32 33; BMS current high-voltage status = 2; 0 "HV open" High voltage not connected; 1 "Precharge or Precheck" Precharge / Precheck in progress; 2 "HV closed" High voltage connected; 3 "Fail to HV on" High voltage connection failed.

[0028] 8) After the VCU confirms that the high voltage has been applied, it enables the DC-DC converter via the CAN network. Once the DC-DC converter is successfully enabled, the high voltage electrical appliances are enabled. Ready state activation phase: 9) The VCU detects that the vehicle has no charging signal, the gear is in N gear, and the brake air pressure is normal; the VCU sends a Ready status and the high-voltage power-on process is completed.

[0029] It also includes power-down strategies, such as Figure 3As shown: The process from the power-down command trigger to the complete disconnection of the high-voltage circuit is the core of "load unloading → active discharge → circuit disconnection", with a specially designed MCU active discharge step.

[0030] Upon receiving a normal (key) or level 3 fault power-down command, the VCU disables all high-voltage electrical components and sends a BMS power-down command. After the BMS detects that the conditions are met, it disconnects the main negative and main positive relays as required and sends a high-voltage power-down completion signal to the vehicle controller. The VCU instructs the MCU to actively discharge all high-voltage electrical circuits. After the discharge completion requirement is met, the vehicle controller disables the DC-DC converter and motor controller via the CAN bus. Once all high-voltage electrical components are ready for low-voltage power-down, the vehicle controller then disconnects the low-voltage power supply via a hard-wired signal.

[0031] The specific procedure for energizing high voltage is as follows: Power-down triggering and load unloading phase: 1) The VCU receives a key power-off command or detects a level 3 fault, triggering the power-off process; Among them, the BMS can send a "request to reduce high voltage" command normally when there is no fault; send a "request to reduce high voltage" command when a fault in the fault table requests the vehicle to reduce high voltage; send a "request to reduce high voltage" command when a limit fault in the fault table or a fault that the BMS can cut off high voltage; and trigger the power-off process.

[0032] 2) The VCU sends a command to disable all high-voltage electrical appliances, and after confirming that the high-voltage electrical appliances are disabled, it sends a command to reduce the high voltage to the BMS. 3) The BMS monitors the bus current in real time.

[0033] Main circuit disconnection and active discharge phase (core safety design): 4) When a high voltage command is received and lasts for 200ms, and the bus current is less than or equal to 5A and lasts for a third time (e.g., 5s), the BMS control will sequentially disconnect the main positive and main negative relays, and the BMS will send a high voltage completion message to the VCU. After a 5s delay, the BMS will go into sleep mode. 5) After the VCU receives the high voltage, it instructs the MCU to start the active discharge function to release the residual electrical energy in all high-voltage power circuits; 6) The MCU collects the voltage between the positive and negative buses of the main circuit in real time and feeds it back to the VCU through the CAN network; 7) When the bus voltage drops to the safe threshold (less than 60V), the MCU feedback discharge is completed.

[0034] Low-voltage power-on completion stage: 8) The VCU receives the MCU discharge completion signal and enters the low-voltage power-down preparation phase; 9) After each high-voltage node completes data storage and reports no abnormalities, the VCU disconnects the hard wire for low-voltage wake-up, completes low-voltage power-off, and then goes into sleep mode after a 10-second delay.

[0035] It also includes charging strategies, such as Figure 4 As shown: The process from connecting to the charging interface to the completion of charging is the core of "connection detection → charging control → termination when fully charged", and the charging circuit protection is realized by relying on BDU.

[0036] BMS wakes up during charging and waits for high voltage to be applied. After the vehicle completes the high voltage application, it enters fast charging according to the standard (national standard) charging process. After the battery is fully charged, BMS disconnects the fast charging relay and waits for VCU instructions to determine whether to enter the corresponding state or process (high voltage discharge state, high voltage reduction process).

[0037] The specific charging process is as follows: Charging wake-up and high-voltage preparation phase: 1) The charging equipment connects to the vehicle via the CS1 or CS2 interface, and the BMS is woken up by charging; 2) The BMS waits for the vehicle's high voltage to be powered on, and the VCU completes the vehicle's high voltage establishment according to the high voltage power-on procedure (same as "high voltage power-on procedure"). 3) The BMS sends the corresponding charging connection signal to the VCU. The VCU performs charging and driving mutual exclusion. The vehicle and the charging equipment complete the communication handshake, confirm the charging parameters, and meet the national standard charging process requirements.

[0038] Fast charging process stages: 4) Following the national standard charging procedure, the VCU enters fast charging mode and sends a charging permission command to the BDU and BMS; 5) After the BMS receives the charging permission command and determines that the conditions for entering the corresponding charging mode are met, it controls the closing of the fast charging relay, and the charging energy is input into the battery system through the BDU; (if the BMS receives a high voltage command from the VCU when charging in the OFF position, it must first go through the high voltage power-on process). 6) Overcurrent protection is monitored in real time by the current sensor in the circuit. When an overcurrent occurs, the BMS limits the discharge power. If the load does not respond for 30 seconds, the relay overcurrent protection will be cut off. Under extreme conditions, the BDU achieves short-circuit protection through the fuse. The BMS monitors the battery voltage, SOC and temperature in real time and dynamically adjusts the charging current. 7) The VCU, in conjunction with the BMS, feeds back the charging status to the charging equipment to ensure a stable charging process.

[0039] Charging termination and subsequent procedures: 8) When the conditions for exiting the corresponding charging mode are met, the corresponding charging mode stop process will be entered; Exit charging conditions: full charge, exit charging failure, card swipe stop, VCU prohibits charging, etc., such as when the battery SOC reaches the preset full charge value or the BMS detects a fault, etc. 9) The BMS controls the fast charging relay to cut off, and the BMS sends a charging completion signal to the VCU; 10) After receiving the charging completion signal, the VCU issues an instruction according to the requirements, and the BMS enters the corresponding state or process (high-voltage discharge state or executes the high-voltage power-off process). After that, the charging equipment disconnects from the vehicle and is disconnected. (In the On position, the charging is completed and the HVON state is maintained. In the OFF position, the charging is completed and the VCU requests power-off to go through the high-voltage power-off process before going into sleep mode).

[0040] Air conditioning activation strategy: After the high voltage is successfully applied, the VCU will activate the air conditioning via CAN enable control as needed. 0x1: VCU_PasAcAllow, 0x1: VCU_PasPtcAllow. After receiving the VCU command and the driver's request, the TMS controller will activate the air conditioning for cooling or heating.

[0041] This embodiment provides a high-voltage power distribution system and control method for heavy-duty electric vehicles. By optimizing the vehicle's CAN network communication mechanism and high-voltage control strategy, the hardware of the high-voltage power distribution architecture is simplified. While reducing hardware costs and the number of system nodes, the control method of enabling electrical appliances sequentially through centralized pre-charging and utilizing CAN networking improves the control reliability and fault prediction of nodes, effectively enhancing the overall safety of the high-voltage system.

[0042] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A high-voltage power distribution system for heavy-duty electric vehicles, characterized in that, include: The battery system outputs high-voltage direct current. The integrated battery power distribution unit is connected to the main positive and main negative busbars of the battery system. It integrates a high-voltage main circuit switching module, a centralized pre-charge circuit and a short-circuit protection module, which are used for centralized switching control of high-voltage power and centralized pre-charge management of all high-voltage power circuits. The charging interface is connected to the integrated battery power distribution unit via a charging bus for external charging. The integrated power electronics unit, connected to the integrated battery distribution unit via the main circuit bus, integrates a motor controller, DC-DC converter, auxiliary system controller, and power distribution module. It forms multiple high-voltage power circuits by connecting corresponding high-voltage electrical appliances. Through the power distribution logic integrated within the integrated power electronics unit, the high-voltage electrical energy delivered by the integrated battery distribution unit is distributed to each high-voltage power circuit. The motor controller is configured to actively discharge the high-voltage power circuits. The power distribution system and high-voltage electrical appliances are controlled via the vehicle's CAN network for at least power-on / off and fault detection.

2. The high-voltage power distribution system for heavy-duty electric vehicles according to claim 1, characterized in that, The high-voltage main circuit switching module includes one main positive relay, one main negative relay and one main positive precharge relay; the centralized precharge circuit is composed of the main positive precharge relay and one precharge resistor connected in series.

3. The high-voltage power distribution system and control method for heavy-duty electric vehicles according to claim 1, characterized in that, The short-circuit protection module includes two manual maintenance switches with built-in fuses, which are used to control two branches respectively. The two branches are connected in parallel and then connected in series at the front end of the battery's main positive bus into the integrated battery power distribution unit. It also includes a charging circuit fuse, which is connected in series in the branch connecting the charging interface and the integrated battery power distribution unit.

4. A high-voltage power distribution control method for heavy-duty electric vehicles, characterized in that, A heavy-duty electric vehicle high-voltage power distribution system according to any one of claims 1-3; the method includes a power-on strategy: Once the power-on wake-up conditions are met, the vehicle controller sends a high-voltage command. The battery management system sequentially closes the main negative relay and the main positive pre-charge relay according to preset conditions to start centralized pre-charging of the high-voltage power circuit. After the pre-charging is successfully judged, the main positive relay is closed and the pre-charge relay is opened. After success, the high-voltage completion status is reported to the vehicle controller. Once the vehicle controller confirms that the high voltage connection is complete, it sequentially enables the DC-DC converter and high-voltage electrical components via the vehicle's CAN network. After the vehicle controller detects that the vehicle meets the conditions, it sends a driving status, and the high-voltage power-on process is completed.

5. The high-voltage power distribution control method for heavy-duty electric vehicles according to claim 4, characterized in that, The conditions for power-on wake-up include: the vehicle controller receiving the vehicle power-on signal, and low-voltage wake-up including all high-voltage nodes such as the integrated battery power distribution unit, integrated power electronics unit, and battery management system; After each high-voltage node has a self-test with no faults and the battery management system sends a discharge permission message, the vehicle controller sends a high-voltage connection command.

6. The high-voltage power distribution control method for heavy-duty electric vehicles according to claim 4, characterized in that, The vehicle controller prevents high-voltage electrical appliances from operating before the battery management system closes the main negative relay.

7. The high-voltage power distribution control method for heavy-duty electric vehicles according to claim 5, characterized in that, The self-test without faults includes determining whether each high-voltage relay is disconnected and fault-free through summary data collection, whether there are no high-voltage interlock faults, and whether the fault list does not allow high-voltage faults on the system.

8. The high-voltage power distribution control method for heavy-duty electric vehicles according to claim 4, characterized in that, It also includes power-down strategies: After receiving a normal or level 3 fault power-down command, the vehicle controller sends a command to disable all high-voltage electrical appliances and sends a power-down command to the battery management system. After the battery management system detects that the conditions are met, it disconnects the main negative and main positive relays as required and sends the high voltage down to the vehicle controller. The vehicle controller instructs the motor controller to start actively discharging all high-voltage power circuits. After the discharge completion requirements are met, the vehicle controller disables the DC-DC converter and motor controller via the CAN bus. Once all high-voltage electrical appliances are ready to be powered down at low voltage, the vehicle controller then cuts off the low-voltage power supply via a hard-wired signal.

9. A high-voltage power distribution control method for heavy-duty electric vehicles according to claim 8, characterized in that, During active discharge, the motor controller collects the voltage between the positive and negative buses of the main circuit in real time and feeds it back to the vehicle controller via the CAN network; when the voltage drops to a safe threshold, the motor controller reports that the discharge is complete.

10. A high-voltage power distribution control method for heavy-duty electric vehicles according to claim 4, characterized in that, It also includes charging strategies: the battery management system wakes up for charging and waits for high voltage to be applied; after the vehicle completes the high voltage application, it enters fast charging according to the standard charging process; after the battery is fully charged, the battery management system disconnects the fast charging relay and waits for the vehicle controller to determine whether to enter the corresponding state or process.

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