Low-voltage battery pack electrical system for industrial vehicle and control method

Abstract

The invention relates to a low-voltage battery pack electrical system for an industrial vehicle and a control method, and belongs to the technical field of battery and industrial vehicle electrical architecture design and control. High voltage output by a battery pack is converted into low voltage through a DC / DC module, and then constant electricity and wake-up signals are provided for a BMS controller and a VCU controller; therefore, control over conventional functions (upper and lower high voltage, charging and heating) of the vehicle is achieved in cooperation with the BMS controller, the DC / DC module does not need to conduct frequent charging and discharging management like a lead-acid storage battery, control is convenient, efficient and safe operation of the battery system can be achieved, and the BMS controller can be reversely awakened to improve the safety of the vehicle under the abnormal condition of the battery.

Description

Technical Field

[0001] This invention relates to an electrical system and control method for a low-voltage battery pack used in industrial vehicles, belonging to the field of battery and industrial vehicle electrical architecture design and control technology. Background Technology

[0002] The electrification of industrial vehicles (such as forklifts, tractors, and pallet trucks) has become an inevitable trend for green and low-carbon transformation in logistics warehousing, ports, and manufacturing workshops. Compared with traditional internal combustion engine vehicles, electric industrial vehicles can achieve "zero emissions" at the end, have lower life cycle operating costs, and are of great significance in improving air quality in the working environment and reducing greenhouse gas emissions. They are a key path to practicing the concept of green development.

[0003] Currently, electric industrial vehicles on the market generally use lithium-ion batteries as their power source. However, the electrical architecture and control methods of existing battery packs still have many shortcomings, such as: 1) Some vehicles have eliminated the use of low-voltage lead-acid batteries, resulting in no constant power supply and making it impossible to wake up the vehicle in case of an emergency; 2) For vehicles equipped with low-voltage lead-acid batteries, the lead-acid batteries have a short lifespan, pollute the environment, and require constant charging and discharging management, making control relatively complex. Summary of the Invention

[0004] The purpose of this invention is to provide an electrical system and control method for a low-voltage battery pack in industrial vehicles. A DC / DC module converts the high voltage output from the battery pack into low voltage, providing constant power and wake-up signals to the BMS controller and VCU controller. This, in conjunction with the BMS controller, enables the vehicle's routine functions (high voltage adjustment, charging, heating) control. Unlike lead-acid batteries, the DC / DC module does not require frequent charging and discharging management, making control convenient and enabling efficient and safe operation of the battery system. Furthermore, in case of battery malfunction, it can reverse-wake up the BMS controller to improve vehicle safety.

[0005] In a first aspect, the present invention provides a low-voltage battery pack electrical system for industrial vehicles, comprising: The system includes a battery pack, a BMS controller, a VCU controller, and a DC / DC module. The VCU controller is connected to the BMS controller via the vehicle's CAN bus. The DC / DC input circuit connects the positive terminal of the battery pack to the negative terminal of the battery pack via a manual switch, a DC / DC fuse, a DC / DC enable port, a DC / DC positive input port, a DC / DC negative input port, and a main circuit fuse. The DC / DC output circuit includes a first DC / DC power supply branch, a second DC / DC power supply branch, and a DC / DC wake-up branch connected in parallel; The first DC / DC power supply branch is connected from the positive output port of the DC / DC module to the negative output port of the DC / DC module via the low-voltage positive power supply port of the BMS controller and the low-voltage negative power supply port of the BMS controller. The second DC / DC power supply branch is connected from the positive output port of the DC / DC module to the negative output port of the DC / DC module via the positive power supply port of the battery pack interface, the low-voltage positive power supply port of the VCU controller, the low-voltage negative power supply port of the VCU controller, and the negative power supply port of the DC / DC module of the battery pack interface. The DC / DC wake-up branch is connected from the positive output port of the DC / DC module to the first terminal of the key switch via the positive power supply port of the battery pack interface. The second terminal of the key switch is connected to the vehicle wake-up port of the VCU controller and to the DC / DC wake-up port of the BMS controller via the auxiliary wake-up port of the battery pack interface. The battery discharge circuit connects the positive terminal of the battery pack to the negative terminal of the battery pack via a main positive relay, the positive discharge port of the battery box, the negative discharge port of the battery box, a main negative relay, and a main circuit fuse. Both the main positive relay and the main negative relay are communicatively connected to the BMS controller. The battery pre-charge circuit connects the positive terminal of the battery pack to the negative terminal of the battery pack via a pre-charge relay, a pre-charge resistor, the positive discharge port of the battery box, the negative discharge port of the battery box, the main negative relay, and the main circuit fuse. The pre-charge relay is communicatively connected to the BMS controller.

[0006] Optionally, it also includes: A fast charging dock is used to connect to a charging pile. The fast charging dock is connected to the BMS controller via a charging CAN bus. The fast charging auxiliary circuit includes a fast charging auxiliary power supply branch and a fast charging auxiliary wake-up branch connected in parallel; The fast charging auxiliary power supply branch is connected from the fast charging positive power supply port of the fast charging socket through the fast charging auxiliary diode, the low-voltage positive power supply port of the BMS controller, and the low-voltage negative power supply port of the BMS controller to the fast charging negative power supply port of the fast charging socket. The fast charging auxiliary wake-up branch route connects the fast charging positive power supply port of the fast charging dock to the fast charging negative power supply port of the fast charging dock through the fast charging positive activation port and the fast charging negative activation port of the BMS controller. The fast charging connection confirmation circuit is connected from the charging connection feedback port of the fast charging socket to the charging connection confirmation port of the BMS controller. The fast charging circuit is connected from the fast charging DC positive output port of the fast charging socket through a fast charging positive relay, the positive terminal of the battery pack, the negative terminal of the battery pack, and a fast charging negative relay to the fast charging DC negative output port of the fast charging socket; both the fast charging positive relay and the fast charging negative relay are communicatively connected to the BMS controller.

[0007] Optionally, it also includes: The fast charging temperature acquisition circuit connects the temperature detection port of the fast charging socket to the temperature acquisition port of the BMS controller. The fast charging heating circuit is connected from the fast charging DC positive output port of the fast charging socket through a fast charging positive relay, a heating positive relay, a heating fuse, a heating film, a heating negative relay, and a fast charging negative relay to the fast charging DC negative output port of the fast charging socket.

[0008] Optionally, it also includes: An on-board charger is used to connect to mains power via a power plug, and the on-board charger is connected to the BMS controller via a charging CAN bus. The slow charging auxiliary circuit includes a slow charging auxiliary power supply branch and a slow charging auxiliary wake-up branch connected in parallel; The slow charging auxiliary power supply branch is connected from the slow charging positive power supply port of the vehicle charger through the slow charging positive power supply port of the battery pack interface, the slow charging diode, the low-voltage positive power supply port of the BMS controller, the low-voltage negative power supply port of the BMS controller, and the battery pack slow charging negative power supply port of the battery pack interface to the charger slow charging negative power supply port of the vehicle charger. The slow-charging auxiliary wake-up branch connects the slow-charging positive power supply port of the on-board charger to the slow-charging wake-up port of the BMS controller through the slow-charging positive power supply port of the battery pack interface. The slow charging circuit is connected from the slow charging DC positive output port of the on-board charger through the slow charging positive port of the battery box, the slow charging positive relay, the positive terminal of the battery pack, the negative terminal of the battery pack, the slow charging negative relay, and the slow charging negative port of the battery box to the slow charging DC negative output port of the on-board charger; the slow charging positive relay and the slow charging negative relay are both connected to the BMS controller. The slow charging connection confirmation circuit is connected from the slow charging connection feedback port of the battery pack interface to the slow charging connection confirmation port of the BMS controller. The slow charging control circuit is connected to the slow charging control port of the BMS controller via the slow charging signal input port of the battery pack interface.

[0009] Optionally, it also includes: The slow charging heating circuit is connected from the slow charging DC positive output port of the on-board charger through the slow charging positive port of the battery box, the slow charging positive relay, the heating positive relay, the heating fuse, the heating film, the heating negative relay, the slow charging negative relay, and the slow charging negative port of the battery box to the slow charging DC negative output port of the on-board charger.

[0010] Optionally, it also includes: The discharge heating circuit consists of the positive terminal of the battery pack, a current acquisition module, a heating positive relay, a heating fuse, a heating film, a heating negative relay, and a main circuit fuse connected to the negative terminal of the battery pack.

[0011] Secondly, the present invention provides a control method for a low-voltage battery pack electrical system for industrial vehicles, which is based on the aforementioned low-voltage battery pack electrical system for industrial vehicles, the control method comprising: When the vehicle needs high-voltage power-on, the manual switch is closed, the DC / DC input circuit is turned on, and the first DC / DC power supply branch supplies power to the BMS controller. After the key switch is closed, the DC / DC wake-up branch is turned on, activating the BMS controller and VCU controller. The second DC / DC power supply branch supplies power to the VCU controller. After the BMS controller and VCU controller are powered on and running, the VCU controller sends a high-voltage power-on command to the BMS controller via the vehicle CAN bus. After receiving the high-voltage power-on command, the BMS controller performs a self-test. If there are no abnormalities in the self-test, it controls the battery pack to perform the high-voltage power-on process according to the high-voltage power-on command sent by the VCU controller. The BMS controller controls the main negative relay, pre-charge relay, and main positive relay to close sequentially. After the BMS controller detects that the main negative relay, pre-charge relay, and main positive relay have all been energized, it disconnects the pre-charge relay, and the high-voltage power-on is completed. If the BMS controller detects a closing fault in the main negative relay, pre-charge relay, or main positive relay, or a disconnection fault in the pre-charge relay, the high-voltage power-on fails and the cause of the fault is uploaded to the management terminal via the vehicle CAN bus. When the vehicle needs to perform a normal high-voltage power-down, the VCU controller sends a high-voltage power-down command to the BMS controller through the vehicle CAN. The BMS controller first controls the main positive relay to disconnect, and then controls the main negative relay to disconnect. If the BMS controller detects a disconnection fault in the main positive relay or the main negative relay, the high-voltage power-down fails and the cause of the fault is uploaded to the management terminal through the vehicle CAN. When the BMS controller detects a vehicle fault, it needs to perform an abnormal high-voltage power-down. The BMS controller requests a high-voltage power-down control request from the VCU controller via the vehicle CAN bus. After receiving the request, the VCU controller adjusts the vehicle to a safe operating condition according to preset rules, and then replies with a high-voltage power-down permission command to the BMS controller via the vehicle CAN bus. The BMS controller then executes the abnormal high-voltage power-down procedure. If the BMS controller does not receive a high-voltage power-down permission command from the VCU controller within a preset time after requesting the high-voltage power-down control request, it automatically executes the abnormal high-voltage power-down procedure. The BMS controller first controls the main positive relay to disconnect, and then controls the main negative relay to disconnect. If the BMS controller detects a disconnection fault in either the main positive or main negative relay, the high-voltage power-down fails, and the cause of the fault is uploaded to the management terminal via the vehicle CAN bus.

[0012] Thirdly, the present invention provides another control method for a low-voltage battery pack electrical system for industrial vehicles, which is based on the aforementioned low-voltage battery pack electrical system for industrial vehicles, the control method comprising: When the vehicle needs to be fast charged, if the manual switch is closed, the first DC / DC power supply branch and the DC / DC wake-up branch are connected, and the BMS controller is woken up and powered on. If the manual switch is open, when the charging gun of the fast charging pile is inserted into the fast charging socket, the fast charging auxiliary power supply branch and the fast charging auxiliary wake-up branch are connected, and the BMS controller is woken up and powered on. After the BMS controller determines that the charging gun and the fast charging dock are successfully connected through the fast charging connection confirmation circuit, the BMS controller controls the fast charging positive relay and the fast charging negative relay to close to fast charge the battery pack. During the charging process, the BMS controller and the fast charging dock exchange charging data through the charging CAN. When charging ends normally or abnormally, the BMS controller sends a fast charging stop request to the fast charging dock. After receiving the fast charging stop request, the fast charging dock adjusts the charging current to a safe range according to preset rules and replies to the BMS controller with a fast charging stop permission command. After receiving the fast charging stop permission command, the BMS controller controls the fast charging positive relay and fast charging negative relay to disconnect, and fast charging ends.

[0013] Fourthly, the present invention provides another control method for a low-voltage battery pack electrical system for industrial vehicles, which is based on the aforementioned low-voltage battery pack electrical system for industrial vehicles, the control method comprising: When the vehicle needs to be charged slowly, if the manual switch is closed, the first DC / DC power supply branch and the DC / DC wake-up branch are turned on, and the BMS controller is woken up and powered on. If the manual switch is open, the on-board charger is connected to the mains power through the power plug, the slow charging auxiliary power supply branch and the slow charging auxiliary wake-up branch are turned on, and the BMS controller is woken up and powered on. After the BMS controller determines that the on-board charger and the battery box are successfully connected through the slow charging connection confirmation circuit, it controls the slow charging positive relay and the slow charging negative relay to close to slowly charge the battery pack. During the charging process, the BMS controller and the on-board charger exchange charging data through the charging CAN. When charging ends normally or abnormally, the BMS controller sends a slow charging stop request to the on-board charger. After receiving the slow charging stop request, the on-board charger 8 adjusts the charging current to a safe range according to preset rules and replies to the BMS controller with a slow charging stop permission command. After receiving the slow charging stop permission command, the BMS controller controls the slow charging positive relay and the slow charging negative relay to disconnect, and the slow charging ends.

[0014] Fourthly, the present invention provides yet another control method for a low-voltage battery pack electrical system for industrial vehicles, which is based on the aforementioned low-voltage battery pack electrical system for industrial vehicles, the control method comprising: After the vehicle is powered off, the manual switch is closed, the DC / DC input circuit is turned on, the first DC / DC power supply branch provides constant power to the BMS controller, the BMS controller is in sleep mode, the AFE module of the BMS controller is awakened when it detects a battery pack abnormality, the AFE module sends an interrupt signal to the BMS controller, the BMS controller is awakened after receiving the interrupt signal, the BMS controller reads the fault information of the AFE module and executes the corresponding processing program, the BMS controller also uses the vehicle CAN to wake up the VCU controller, the VCU controller enters normal working mode, the VCU controller uploads the fault information read by the BMS controller to the management terminal.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This invention includes a DC / DC input circuit, which connects the positive terminal of the battery pack to the negative terminal 403 via a manual switch, a DC / DC fuse, a DC / DC enable port, a DC / DC positive input port, a DC / DC negative input port, and a main circuit fuse. The DC / DC module can convert the high voltage output from the battery pack into a low voltage. This invention also includes a DC / DC output circuit, comprising a first DC / DC power supply branch, a second DC / DC power supply branch, and a DC / DC wake-up branch connected in parallel. The first DC / DC power supply branch connects the positive output port of the DC / DC module to the negative output port of the DC / DC module via the low-voltage positive power supply port and the low-voltage negative power supply port of the BMS controller. The second DC / DC power supply branch connects the positive output port of the DC / DC module to the negative output port of the DC / DC module via the positive power supply port of the battery pack interface, the low-voltage positive power supply port of the VCU controller, the low-voltage negative power supply port of the VCU controller, and the negative power supply port of the battery pack interface. The DC / DC wake-up branch connects the positive output port of the DC / DC module to the first terminal of the key switch via the positive power supply port of the battery pack interface. The second terminal of the key switch is connected to the vehicle wake-up port of the VCU controller and to the DC / DC wake-up port of the BMS controller via the auxiliary wake-up port 504 of the battery pack interface. The DC / DC module of the present invention can supply power to the BMS controller and the VCU controller respectively through the first DC / DC power supply branch and the second DC / DC power supply branch, and the DC / DC wake-up branch can provide wake-up signals to the BMS controller and the VCU controller. The DC / DC module can work with the BMS controller to control the vehicle's routine functions (high voltage, charging, heating); unlike lead-acid batteries, the DC / DC module does not require frequent charging and discharging management, making it easy to control and enabling efficient and safe operation of the battery system. Furthermore, in case of battery malfunction, it can wake up the BMS controller to improve vehicle safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the electrical architecture of a low-voltage battery pack electrical system for industrial vehicles provided in an embodiment of the present invention; Figure 2 This is a flowchart of the high-voltage power-on control process for a low-voltage battery pack electrical system for industrial vehicles, provided in an embodiment of the present invention. Figure 3 This is a flowchart illustrating the normal high-voltage down-pressure control of an electrical system for a low-voltage battery pack in an industrial vehicle, provided in an embodiment of the present invention. Figure 4 This is a flowchart illustrating the abnormal high voltage flow of the electrical system for a low-voltage battery pack in an industrial vehicle, provided as an embodiment of the present invention. Detailed Implementation

[0017] It should be noted that: The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0018] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0019] Combination Figure 1 This embodiment provides an electrical system for a low-voltage battery pack for industrial vehicles, which includes a battery pack 4 (a lithium battery pack in this embodiment), a BMS controller 1, a VCU controller 923, and a DC / DC module 2 (12VDC or 24VDC). The VCU controller 923 is connected to the BMS controller 1 via the vehicle CAN bus (including vehicle CAN H and vehicle CAN L).

[0020] The low-voltage battery pack electrical system of this embodiment is applied to the battery pack 4 with a relatively small voltage. The voltage of the battery pack 4 is generally <80V. It is composed of individual cells 401 connected in series and parallel to achieve the designed voltage and capacity values. The battery pack 4 stores or releases battery energy. When the capacity is low, it converts electrical energy into the chemical energy of the lithium battery through charging. When discharging, it is used to drive the vehicle to work and move, converting the chemical energy of the lithium battery into electrical energy and mechanical energy.

[0021] In this embodiment, the DC / DC module 2 provides constant power to the VCU controller 923, BMS controller 1, and other vehicle components. The overall electrical architecture is simpler and more flexible, enabling efficient and safe operation of the battery system under the centralized control of the BMS controller. The BMS controller 1 is the control core of the battery pack system. By collecting data on the temperature, individual cell voltage, current, and other charging and discharging data of the battery pack 4, the BMS controller 1 intelligently manages and maintains each individual battery cell 401, monitors the status of each individual battery cell 401, and prevents overcharging and over-discharging of individual batteries 401 to extend battery life. The core functions of the BMS controller 1 include battery status monitoring, battery status estimation, battery protection, battery equalization, heating, data communication and storage, national standard fast charging, national standard slow charging, relay control, and other vehicle control functions.

[0022] The DC / DC module 2 is an isolated-step-down DC / DC converter. Electrical isolation between the input and output terminals is achieved through a transformer and related devices. The DC / DC module 2 can convert the high voltage of the lithium battery pack into a low voltage (generally 12V or 24V, and the DC / DC in this embodiment is preferably a 12V output type) for powering the VCU controller 923, BMS controller 1, instruments and other vehicle components.

[0023] The low-voltage battery pack electrical system of this embodiment includes a DC / DC input circuit and a DC / DC output circuit. The DC / DC input circuit connects the positive terminal 401 of the battery pack 4 to the negative terminal 403 of the battery pack 4 via a manual switch 901, a DC / DC fuse 902, a DC / DC enable port 204, a DC / DC positive input port 203, a DC / DC negative input port 202, and a main circuit fuse 920. The DC / DC output circuit includes a first DC / DC power supply branch, a second DC / DC power supply branch, and a DC / DC wake-up branch connected in parallel. The first DC / DC power supply branch connects the DC / DC positive output port 202 of the DC / DC module 2 to the DC / DC negative output port 201 of the BMS controller 1 via the low-voltage positive power supply port 120 and the low-voltage negative power supply port 121 of the BMS controller 1. 01; The second DC / DC power supply branch route is from the DC / DC positive output port 202 of DC / DC module 2 through the DC / DC positive power supply port 501 of battery pack interface 5, the low-voltage positive power supply port 927 of VCU controller 923, the low-voltage negative power supply port 928 of VCU controller 923, and the DC / DC negative power supply port 513 of battery pack interface 5 to the DC / DC negative output port 201 of DC / DC module 2; the DC / DC wake-up branch route is from the DC / DC positive output port 202 of DC / DC module 2 through the DC / DC positive power supply port 501 of battery pack interface 5 to the first end of key switch 921, the second end of key switch 921 is connected to the vehicle wake-up port 923 of VCU 923 and connected to the DC / DC wake-up port 124 of BMS controller 1 through the auxiliary wake-up port 504 of battery pack interface 5.

[0024] The manual switch 901 is located outside the battery box. Through the manual switch 901 and the built-in DC / DC module 2, the power supply and disconnection of the entire low-voltage system can be achieved, replacing the traditional low-voltage lead-acid battery architecture. This improves system control costs, and since low-voltage lead-acid batteries require charging, the low-voltage electricity is directly converted from the battery pack 4 via the DC / DC module 2, eliminating the need for charging and simplifying the control method. When the vehicle is not in use for an extended period, the manual switch 901 can be disconnected to save power. Under normal circumstances, the manual switch 901 is generally kept closed, and the DC / DC module 2 provides power to the VCU controller 923, BMS controller 1, instruments, and other vehicle components, enabling the intelligent, safety, and memory functions required by the vehicle.

[0025] The low-voltage battery pack electrical system of this embodiment also includes a battery discharge circuit and a battery pre-charge circuit. The battery discharge circuit connects the positive terminal 401 of the battery pack 4 to the negative terminal 403 of the battery pack 4 via a main positive relay 914, the positive discharge port 916 of the battery box, the negative discharge port 917 of the battery box, a main negative relay 909, and a main circuit fuse. Both the main positive relay 914 and the main negative relay 909 are communicatively connected to the BMS controller 1. The battery pre-charge circuit connects the positive terminal 401 of the battery pack 4 via a pre-charge relay 912, a pre-charge resistor 913, the positive discharge port 916 of the battery box, the negative discharge port 917 of the battery box, the main negative relay 909, and a main circuit fuse to the negative terminal 403 of the battery pack 4. The pre-charge relay 912 is communicatively connected to the BMS controller 1.

[0026] The battery pack electrical system of this embodiment can realize the national standard fast charging, national standard slow charging, discharging and heating functions of battery pack 4, so as to realize the battery's energy replenishment and drive the vehicle to work and move.

[0027] The battery pack electrical system includes a fast charging dock 6 for connecting to a charging pile 7. The fast charging dock 6 is connected to the BMS controller 1 via a charging CAN bus. The fast charging auxiliary circuit of the battery pack electrical system includes a parallel fast charging auxiliary power supply branch and a fast charging auxiliary wake-up branch. The fast charging auxiliary power supply branch connects the fast charging positive power supply port 602 of the fast charging dock 6 through the fast charging auxiliary diode 929, the low-voltage positive power supply port 120 of the BMS controller 1, and the low-voltage negative power supply port 121 of the BMS controller 1 to the fast charging negative power supply port 603 of the fast charging dock 6. The fast charging auxiliary wake-up branch connects the fast charging positive power supply port 602 of the fast charging dock 6 through the fast charging positive activation port 121 of the BMS controller 1. 34. The fast charging negative activation port 135 of the BMS controller 1 is connected to the fast charging negative power supply port 603 of the fast charging socket 6; the battery pack electrical system also includes a fast charging connection confirmation circuit and a fast charging circuit. The fast charging connection confirmation circuit is connected to the charging connection confirmation port 133 of the BMS controller 1 via the charging connection feedback port 601 of the fast charging socket; the fast charging circuit is connected to the fast charging DC negative output port 102 of the fast charging socket 6 via the fast charging positive relay 915, the positive terminal of the battery pack 4, the negative terminal of the battery pack 4, and the fast charging negative relay 910; the fast charging positive relay 915 and the fast charging negative relay 910 are both communicatively connected to the BMS controller 1.

[0028] The battery pack electrical system in this embodiment performs fast charging in accordance with national standards such as GB / T27930-2015, GB / T18487.1-2015, GB / T 20234.1-2015, and GB / T 20234.3-2015. After the fast charging gun is inserted into the fast charging socket 6, clicking "Start Charging" on the charging pile 7 activates the fast charging auxiliary wake-up branch and wakes up the BMS controller 1. The BMS controller 1 controls the fast charging positive relay 915 and fast charging negative relay 910 to close, activating the fast charging circuit to fast charge the battery. Furthermore, to ensure charging safety, the battery pack electrical system in this embodiment also includes a fast charging temperature acquisition circuit. This circuit is connected from the temperature detection port of the fast charging socket 6 to the temperature acquisition port of the BMS controller 1. If the charging temperature is abnormal, the BMS controller 1 can execute a pre-set program to terminate fast charging.

[0029] The battery pack electrical system includes an on-board charger 8, which is connected to the mains power supply via a power plug 809. The on-board charger 8 is connected to the BMS controller 1 via a charging CAN bus. The battery pack electrical system also includes a slow-charging auxiliary circuit, which includes a parallel slow-charging auxiliary power supply branch and a slow-charging auxiliary wake-up branch. The slow-charging auxiliary power supply branch is connected from the slow-charging positive power supply port 807 of the on-board charger 8 through the slow-charging positive power supply port 503 of the battery pack interface 5, the slow-charging diode (903), the low-voltage positive power supply port 120 of the BMS controller 1, the low-voltage negative power supply port 121 of the BMS controller 1, and the battery pack slow-charging negative power supply port 502 of the battery pack interface to the charger's slow-charging negative power supply port. The slow-charging circuit... The slow-charging DC positive output port 802 of the on-board charger 8 is connected to the slow-charging DC negative output port 801 of the on-board charger 8 via the slow-charging positive port 918 of the battery box, the slow-charging positive relay 911, the positive terminal 401 of the battery pack 4, the negative terminal 403 of the battery pack 4, the slow-charging negative relay 908, and the slow-charging negative port 919 of the battery box. The slow-charging positive relay 911 and the slow-charging negative relay 908 are both communicatively connected to the BMS controller 1. The slow-charging connection confirmation circuit of the battery pack electrical system is connected to the slow-charging connection confirmation port 125 of the BMS controller via the slow-charging connection feedback port 505 of the battery pack interface 5. The slow-charging control circuit of the battery pack electrical system is connected to the slow-charging control port 126 of the BMS controller 1 via the slow-charging signal input port 5 of the battery pack interface 5.

[0030] The battery pack electrical system in this embodiment performs slow charging in accordance with national standards such as GB / T 18487.1-2015, GB / T20234.1-2015, and GB / T 20234.2-2015. After plugging in the slow charging gun and clicking "Start Charging," the slow charging auxiliary power supply branch and the slow charging auxiliary wake-up branch are activated, the BMS controller 1 is woken up and powered on, the slow charging connection confirmation circuit confirms that CC is normal, the BMS controller 1 controls the slow charging positive relay 911 and the slow charging negative relay 908 to close, and the slow charging circuit is activated to fast charge the battery.

[0031] The low-voltage battery pack electrical system of this embodiment also includes a fast-charging heating circuit, a slow-charging heating circuit, and a discharge heating circuit. The fast-charging heating circuit is connected from the fast-charging DC positive output port 101 of the fast-charging socket 6 to the fast-charging DC negative output port 102 of the fast-charging socket 6 via a fast-charging positive relay 915, a heating positive relay 904, a heating fuse 905, a heating film 906, a heating negative relay 907, and a fast-charging negative relay 910. The slow-charging heating circuit is connected from the slow-charging DC positive output port 802 of the on-board charger 8 to the slow-charging DC negative output port 801 of the on-board charger via the slow-charging positive port 918 of the battery box, a slow-charging positive relay 911, a heating positive relay 904, a heating fuse 905, a heating film 906, a heating negative relay 907, a slow-charging negative relay 908, and the slow-charging negative port 919 of the battery box. The discharge heating circuit consists of the positive terminal 401 of the battery pack 4, the current acquisition module 3, the heating positive relay 904, the heating fuse 905, the heating film 906, the heating negative relay 907, and the main circuit fuse 920, all connected to the negative terminal 403 of the battery pack.

[0032] The heating control in this embodiment can be performed individually or in conjunction with fast charging, slow charging, or discharging heating circuits. The heating film 906 features constant power heating. Its two ends are connected to the positive electrode 401 and negative electrode 403 of the battery pack 4, respectively. The heating film 906 can heat the battery pack 4 at low temperatures. It consists of a heating core, an insulator, a connector, wiring harness, and related components. In charging or discharging mode, the heating mode is activated when both the positive heating relay 904 and the negative heating relay 907 are simultaneously turned on; the heating mode is deactivated when either the positive or negative relay 904 is disconnected. The heating fuse 905 can quickly melt when a large heating current flows into the fast charging, slow charging, or discharging heating circuit, thereby protecting the battery.

[0033] The specific control methods will be explained in detail below: Combination Figure 2 When a vehicle requires high-voltage power, the control methods for the electrical system of a low-voltage battery pack in industrial vehicles include: Step 1: By default, manual switch 901 is in the closed state. The voltage of battery pack 4 will pass through positive terminal 401 → current acquisition module 3 → manual switch 901 → DC / DC fuse 902 → DC / DC enable port 204 and DC / DC positive input port 203 → DC / DC negative input port 205 → main circuit fuse 920 → negative terminal 403 of battery pack 4. DC / DC module 2 normally outputs 12V low-voltage DC power. Among them, DC / DC positive output port 202 is connected as constant positive to low-voltage positive power supply port 120 of BMS controller 1, and DC / DC negative output port 201 is connected as constant negative to low-voltage negative power supply port 121 of BMS controller 1. At the same time, DC / DC positive output port 202 is connected to the vehicle-side key switch 921 through the DC / DC positive power supply port 501 of battery pack interface 5 designed in battery box 922.

[0034] Step 2: Close the key switch 921. The DC / DC positive power supply port 501 of the battery pack interface 5 is connected to the first terminal of the key switch 921 on the vehicle side. The second terminal of the key switch 921 is connected to the vehicle wake-up port 923 of the VCU controller 923 and connected to the DC / DC wake-up port 124 of the BMS controller 1 through the auxiliary wake-up port 504 of the battery pack interface 5. After the key switch 921 is closed, the wake-up signal can be input to the vehicle wake-up port 923 of the VCU controller 923 and the DC / DC wake-up port 124 of the BMS controller 1. / DC wake-up port 124 is used to activate BMS controller 1 and VCU controller 923; the DC / DC positive power supply port 501 of battery pack interface 5 is connected to the low-voltage positive power supply port 927 of VCU controller 923, and the DC / DC negative power supply port 513 of battery pack interface 5 is connected to the low-voltage negative power supply port 201 of VCU controller 923 to supply power to VCU controller 923; after BMS controller 1 and VCU controller 923 are powered on and running; VCU controller 923 sends a high-voltage command to BMS controller 1 through twisted pair CAN signals (vehicle CAN H924, vehicle CAN L925); after BMS runs, it will perform self-checks on hardware, communication and battery status, etc. If there are no abnormal faults, it will control battery pack 4 to perform the high-voltage process according to the high-voltage command of VCU controller 923; Step 3: BMS controller 1 controls 114 to close main negative relay 909 via main negative relay. When it detects that the HV G2 voltage at the back end of the main negative relay is close to the negative terminal voltage HV G0 of battery pack 4 (generally the difference is ±5% (TBD)), it is determined that the main negative relay 909 has been successfully engaged. If the main negative relay 909 cannot be closed within 0.5 seconds, a fault will be triggered that the main negative relay 909 cannot be closed, resulting in failure to apply high voltage and uploading the fault cause to the management terminal. Step 4: BMS controller 1 closes precharge relay 912 via precharge relay control 113. Under the action of precharge resistor 913, the precharge current of the entire discharge circuit is limited to the allowable range. When the voltage HVP3 at the back end of precharge relay 912 is detected to be close to the positive terminal voltage HVP1 of battery pack 4 (generally the difference is ±5% (TBD)), it is determined that precharge relay 912 has been successfully engaged. If precharge relay 912 cannot be closed within 0.5 seconds, a precharge relay 912 failure to close fault will be triggered, high voltage connection will fail, and the fault cause will be uploaded to the management terminal. Step 5: BMS controller 1 controls 115 to close main positive relay 914 via main positive relay. When it detects that the HV P3 voltage at the back end of the main positive relay is close to the battery pack positive terminal voltage HV P1 (generally the difference is ±5% (TBD)), it is determined that the main positive relay has been successfully engaged. If the main positive relay cannot be closed within 0.5 seconds, a main positive relay failure to close fault will be triggered, high voltage connection will fail, and the fault cause will be uploaded to the management terminal. Step 6: BMS controller 1 disconnects precharge relay 912 via precharge relay 113, thus completing the high-voltage power-on. If the precharge main positive relay cannot be disconnected within 0.5 seconds, a precharge relay disconnection failure will be triggered, resulting in high-voltage power-on failure and the fault cause being uploaded to the management terminal.

[0035] Combination Figure 3 When the vehicle requires normal high-voltage power, the control methods for the electrical system of the low-voltage battery pack in industrial vehicles include: Step 1: During normal operation of BMS controller 1, VCU controller 923 sends a high-voltage power-down command to BMS controller 1 through twisted pair CAN signals (vehicle CANH924, vehicle CAN L925). Step 2: BMS controller 1 controls the main positive relay 914 to disconnect via the main positive relay 115. When it is detected that the HV P3 voltage at the back end of the main positive relay 914 is not within the range of [battery pack positive terminal voltage HV P1*(1-5%(TBD)), battery pack positive terminal voltage HV P1*(1+5%(TBD))], the main positive relay 914 is considered to have disconnected successfully. If the main positive relay 914 cannot be disconnected within 1 second (TBD), a fault that the main positive relay 914 cannot be disconnected will be triggered, and the cause of the fault will be reported to the management terminal. Step 3: Regardless of whether the main positive relay 914 is successfully disconnected, BMS controller 1 continues to control the main negative relay 909 to disconnect. BMS controller 1 controls 114 to disconnect the main negative relay 909 through the main negative relay. When BMS controller 1 detects that the HV G2 voltage at the back end of the main negative relay 909 is not within the range of [battery pack negative terminal voltage HV G0*(1-5%(TBD)), battery pack negative terminal voltage HV G0*(1+5%(TBD))], it is determined that the main negative relay 909 has been successfully disconnected. If the main negative relay cannot be disconnected within 1 second (TBD), a fault will be triggered that the main negative relay 909 cannot be disconnected, the high voltage will fail, and the fault cause will be uploaded to the management terminal.

[0036] Combination Figure 4 When the BMS controller detects a fault in the vehicle, it needs to perform a high-voltage abnormality power-off. The control methods for the electrical system of the low-voltage battery pack in industrial vehicles include: Step 1: When BMS controller 1 detects a system fault (such as high-level faults such as battery thermal runaway, overheating, low cell voltage, abnormal voltage, etc.) and needs to perform high-voltage control on the whole vehicle, BMS controller 1 requests high-voltage control from VCU controller 923 through twisted pair CAN signals (vehicle CAN H924, vehicle CAN L925). Step 2: When the VCU receives the request to reduce high voltage, it will perform operations such as power reduction and speed reduction according to the vehicle's operating status. Once the vehicle is in a relatively safe condition, the VCU will reply to the BMS with a command to allow the high voltage to be reduced via twisted pair CAN signals (vehicle CAN H924, vehicle CAN L925). Step 3: When BMS controller 1 sends a high-voltage reduction request to VCU controller 923, and does not receive a high-voltage reduction permission command from VCU controller 923 after 10 seconds (TBD), considering vehicle safety and other issues, it will automatically execute the abnormal high-voltage reduction process. Step 4: BMS controller 1 disconnects main positive relay 914 via main positive relay control 115. When it detects that the HV P3 voltage at the back end of the main positive relay is not within the range of [battery pack positive terminal voltage HV P1*(1-5%(TBD)), battery pack positive terminal voltage HV P1*(1+5%(TBD))], it is determined that the main positive relay 914 has been successfully disconnected. If the main positive relay 914 cannot be disconnected within 1 second (TBD), a fault that the main positive relay 914 cannot be disconnected will be triggered, and the cause of the fault will be reported to the management terminal. Step 5: Regardless of whether the main positive relay 914 is successfully disconnected, the BMS will next control the disconnection of the main negative relay 914; the main negative relay 909 is disconnected through the main negative relay control 114. When the HV G2 voltage at the back end of the main negative relay 914 is not within the range of [battery pack negative terminal voltage HV G0*(1-5%(TBD)), battery pack negative terminal voltage HV G0*(1+5%(TBD))], the main negative relay 914 is considered to have been successfully disconnected. If the main negative relay 914 cannot be disconnected within 1 second (TBD), a fault will be triggered indicating that the main negative relay 914 cannot be disconnected, the high voltage will fail, and the fault cause will be uploaded to the management terminal.

[0037] When rapid charging is required in the manual switch 901 closed mode, the control methods for the electrical system of the low-voltage battery pack for industrial vehicles include: Step 1: With manual switch 901 in the closed state, DC / DC module 2 supplies power to BMS controller 1; Step 2: Insert the charging gun 702 from the fast charging station 7 into the fast charging socket 6 on the battery box 922, ensuring that it is properly connected; Step 3: Click the start button on display 701 on the fast charging pile 7; the charging control and interaction between the fast charging pile and the battery pack / BMS strictly comply with the following standards: GB / T 18487.1-2015 Conductive charging system for electric vehicles - Part 1: General requirements, GB / T20234.1-2015 Connecting device for conductive charging of electric vehicles - Part 1: General requirements, GB / T 20234.3-2015 Connecting device for conductive charging of electric vehicles - Part 3: DC charging interface, and GB / T 27930-2015 Communication protocol between off-board conductive charger and battery management system for electric vehicles. Step 4: Click the meter to start charging. The fast charging positive power supply port 602 and fast charging negative power supply port 603 of the fast charging dock 6 output signals to the fast charging positive activation port 134 and fast charging negative activation port 135 of the BMS controller 1 to wake up the BMS controller 1. The BMS controller 1 sends a charging connection confirmation signal CC2 from the charging connection feedback port 601 of the fast charging dock to the charging connection confirmation port 133 of the BMS controller 1 to determine that the charging gun and the fast charging dock 6 are correctly connected. The charging pile is connected to the charging CAN H131 and fast charging CAN L132 of the BMS controller through the charging CANH606 and charging CAN L607 to exchange information (in accordance with GB / T 27930-2015 Communication Protocol between Off-board Conductive Charger and Battery Management System for Electric Vehicles; The BMS controller 1 also detects the first temperature detection port 604 and the second temperature detection port 605 of the fast charging socket 6 through the first temperature acquisition port 136 and the second temperature acquisition port 137 respectively, to monitor the temperature of the fast charging socket 6 at all times and prevent the fast charging socket 6 from being damaged due to high temperature, which would lead to charging safety issues; Step 5: BMS controller 1 controls fast charging positive relay 915 and fast charging negative relay 910 to execute closing commands through fast charging positive relay control 119 and fast charging negative relay control 118, respectively. If the voltage at high voltage acquisition port HV G1 108 is close to the battery pack negative terminal voltage HV G0 (generally the difference is ±5% (TBD)), fast charging negative relay 910 is considered to have closed successfully; if the voltage at high voltage acquisition port HV P2 103 is close to the battery pack positive terminal voltage HV P1 (generally the difference is ±5% (TBD)), fast charging positive relay 915 is considered to have closed successfully. Step 6: During the charging process, BMS controller 1 will send the following messages to charging station 7 cyclically: The Battery Charging Request Message (BCL) includes the battery pack voltage requirement, current requirement, and charging mode request. The Battery Charge Status Message (BCS) includes information such as charging voltage, charging current, highest cell voltage and number, SOC value, and estimated remaining charging time. The Battery Status Information (BSM) message includes the number of the highest single battery cell voltage, the highest / lowest battery temperature, the number corresponding to the highest / lowest temperature, and information such as single cell voltage fault, SOC fault, and current fault. The individual battery voltage message (BMV) contains the voltage values ​​of each individual power battery cell; The individual battery temperature report (BMT) includes the power battery temperature value; During the charging process, the charging pile will send the following information to the BMS controller 1 cyclically: The charging status message (CCS) of the charging pile includes information such as charging voltage, charging current, cumulative charging time, and charging permission flag; Step 7: When fully charged, when the manually set charging cutoff condition is reached, or when the charging station / battery system malfunctions: BMS controller 1 actively stops sending (BST) to allow charging pile 7 to confirm that BMS controller 1 will send a stop charging message to cause charging pile 7 to end the charging process and the reason for ending the charging; When the charging station 7 actively stops charging, it will send a (CST) to the BMS controller 1 to confirm that the charger will end charging and the reason for ending charging. Step 8: Charging complete; BMS controller 1 will send a statistical data message (BSD) to the charging pile 7 to confirm the charging statistics data of BMS controller 1 for this charging process; Charging station 7 will send (CSD) to confirm the charging statistics of the current charging process; Step 9: If an error is detected by either BMS controller 1 or charger during the charging process, an error message will be sent respectively. When BMS controller 1 detects an error, it sends a charging error message (BEM) to charging pile 7 until BMS controller 1 receives a charger identification message (CRM) from charging pile 7 or unplugs the charging plug.

[0038] When the charging pile 7 detects an error, it sends a charging error message (CEM) to the BMS controller 1 until the charging pile 7 receives a BRM message from the BMS controller 1 or the charging plug is unplugged.

[0039] Step 10: When charging ends normally or abnormally, BMS controller 1 sends a fast charging stop request to charging pile 7. Upon receiving the fast charging stop request, charging pile 7 controls the charging current to be <5A (TBD) and sends a fast charging stop command to BMS controller 1. BMS controller 1 will control fast charging positive relay 915 and fast charging negative relay 910 to execute disconnect commands through fast charging positive relay control 119 and fast charging negative relay control 118, respectively. If the voltage value of high voltage acquisition port HV P2 103 is not within the range of [battery pack positive terminal voltage HV P1*(1-5%(TBD)), battery pack positive terminal voltage HV P1*(1+5%(TBD))], it is considered that fast charging positive relay 915 has been disconnected. If the voltage value of high voltage acquisition port HV G1 108 is not within the range of [battery pack positive terminal voltage HV G0*(1-5%(TBD)), battery pack positive terminal voltage HV When the value is within the range of G0*(1+5%(TBD))], the fast charging negative relay 910 is considered to have completed disconnection. Step 10: Fast charging is complete.

[0040] When rapid charging is required in the manual switch 901 off mode, the control methods for the electrical system of the low-voltage battery pack for industrial vehicles include: Step 1: With manual switch 901 in the off state, DC / DC module 2 is not working and cannot supply power to BMS controller 1; Step 2: Insert the charging gun 702 from the fast charging station 7 into the fast charging socket 6 on the battery box 922, ensuring that it is properly connected; Step 3: Click the start button on display 701 on the fast charging pile 7; the charging control and interaction between the fast charging pile and the battery pack / BMS strictly comply with the following standards: GB / T 18487.1-2015 Conductive charging system for electric vehicles - Part 1: General requirements, GB / T20234.1-2015 Connecting device for conductive charging of electric vehicles - Part 1: General requirements, GB / T 20234.3-2015 Connecting device for conductive charging of electric vehicles - Part 3: DC charging interface, and GB / T 27930-2015 Communication protocol between off-board conductive charger and battery management system for electric vehicles. Step 4: Click the meter to start charging. The fast charging positive power supply port 602 of the fast charging dock 6 is connected to the low-voltage positive power supply port 120 of the BMS controller 1 through the fast charging auxiliary diode 929. The fast charging negative power supply port 603 of the fast charging dock 6 is connected to the low-voltage negative power supply port 121 of the BMS controller 1 to replace the DC / DC module 2 to power the BMS controller 1. The fast charging positive power supply port 602 and the fast charging negative power supply port 603 of the fast charging dock 6 output signals to the fast charging positive activation port 134 and the fast charging negative activation port 135 of the BMS controller 1 to wake up the BMS controller 1. The subsequent control method after the BMS controller 1 is powered on and activated is the same as the control method in the manual switch 901 closed mode, and will not be described in detail here.

[0041] When slow charging is required in the manual switch 901 closed mode, the control methods for the electrical system of the low-voltage battery pack for industrial vehicles include: Step 1: The manual switch (901) is in the closed state; Step 2: Powering and activating BMS1 controller 1 with DC / DC module 2, the DC / DC positive output port 202 → BMS controller 1 low-voltage positive power supply port 120 → BMS controller 1 low-voltage negative power supply port 121 → DC / DC module 2 DC / DC negative output port 201 provides constant power to BMS controller 1. Connect the power plug 809 of the on-board charger 8 to the mains power. At this time, the slow charging low-voltage power supply circuit is as follows: on-board charger 8 slow charging positive power supply port 807 → battery pack interface 5 slow charging positive power supply port 503 → slow charging diode 903 → BMS controller 1 low-voltage positive power supply port 120 → BMS controller 1 low-voltage negative power supply port 121 → battery pack interface 5 battery pack interface 5 battery pack slow charging negative power supply port 502 → on-board charger 8 charger slow charging negative power supply port 808, forming a power supply circuit to BMS controller 1. Slow charging activates the BMS circuit: the slow charging positive power supply port 807 of the on-board charger 8 → the slow charging positive power supply port 503 of the battery pack interface 5 → the slow charging wake-up port 123 of the BMS controller 1 → the BMS controller 1, forming a slow charging activation circuit, activating the BMS controller 1 to prepare for slow charging.

[0042] Step 3: Establish communication between the on-board charger 8 and the BMS controller 1. The on-board charger 8 communicates with the BMS controller via the charging CAN bus: On-board charger 8's slow charging CAN bus H804 → Battery pack interface 5's CAN bus H511 → BMS controller 1's charging CAN bus H131 → BMS controller 1 → BMS controller 1's charging CAN bus L132 → Battery pack interface 5's CAN bus L512 → On-board charger 8's slow charging CAN bus L80), where the baud rate is preferably 250Kbps. The fast charging CAN bus and the slow charging CAN bus share the charging CAN bus channels (CAN bus H131, CAN bus L132).

[0043] Step 4: Close the slow charging relay. The BMS controller 1 controls the slow charging positive relay 911 and the slow charging negative relay 908 to execute the closing command through the slow charging positive relay control 116 and the slow charging negative relay control 117, respectively. If the high voltage acquisition port HVG3 106 detects that the voltage of HV G3 at the back end of the slow charging negative relay 908 is close to the voltage of HV G0 at the negative end of the battery pack (generally the difference is ±5% (TBD)), the slow charging negative relay 908 is considered to be closed. If the high voltage acquisition port HV P5 (110) detects that the voltage of HV P5 at the back end of the slow charging positive relay 908 is close to the voltage of HV P1 at the positive end of the battery pack (generally the difference is ±5% (TBD)), the slow charging positive relay 908 is considered to be closed.

[0044] Step 5: During the charging process, BMS controller 1 interacts with the on-board unit in real time. During charging, BMS controller 1 periodically sends battery charging demand and status messages to on-board charger 8, including battery pack voltage requirements, current requirements, maximum single-cell voltage, battery temperature, SOC, remaining charging time, and other charging data. On-board charger 8 periodically sends on-board charger status messages to BMS controller 1, including charging voltage, charging current, cumulative charging time, charging permission flag, and other charging data. Step 6: When fully charged or when the onboard charger / battery system malfunctions: When the BMS controller 1 detects a serious fault, it will send a stop charging request to the on-board charger 8, reduce the charging current and charging voltage to zero, send a charging disallowed flag and information such as the reason for ending the charging; When the on-board charger 8 detects a serious fault, it will actively stop charging and send a command to end charging and the reason for ending charging to the BMS controller 1. Step 7: Charging complete, data interaction; BMS controller 1 will send a statistical data message to on-board charger 8, so that on-board charger 8 can confirm the charging statistics data of BMS controller 1 for this charging process; The on-board charger 8 will send a statistical data message to the BMS controller 1 to confirm the charging statistics of the on-board charger 8 during this charging process; Step 9: When charging ends normally or abnormally, BMS controller 1 sends a charging stop request to on-board charger 8. After receiving the charging stop request, on-board charger 8 controls the charging current. After the on-board charger 8 adjusts the charging current to <5A (TBD), it sends a request to the BMS controller 1 to allow charging to stop. The BMS controller 1 will control the slow charging positive relay 911 and the slow charging negative relay 908 to execute disconnect commands through the slow charging positive relay control 116 and the slow charging negative relay control 117, respectively. If the high-voltage acquisition port HV G3 106 detects that the HV G3 voltage value at the end of the slow charging negative relay 908 is not within the range of [battery pack negative terminal voltage HV G0*(1-5%(TBD)), battery pack positive terminal voltage HV G0*(1+5%(TBD))], it is determined that the slow charging negative relay 908 has been disconnected. If the high-voltage acquisition port HV P5 (110) detects that the HV P5 voltage value at the end of the slow charging positive relay 911 is not within the range of [battery pack negative terminal voltage HV P1*(1-5%(TBD)), battery pack positive terminal voltage HV When the value is within the range of P1*(1+5%(TBD))], the slow charging positive relay 911 is considered to have completed disconnection.

[0045] Step 10: Slow charging is complete.

[0046] When slow charging is required in the manual switch 901 off mode, the control methods for the electrical system of the low-voltage battery pack for industrial vehicles include: Step 1: When manual switch 901 is in the off state, DC / DC module 2 does not work and cannot supply power to BMS controller 1; Step 2: Connect the power plug 809 of the on-board charger 8 to the mains power. The slow charging positive power supply port 807 of the on-board charger 8 connects to the slow charging negative power supply port 808 of the on-board charger 8 via the slow charging positive power supply port 503 of the battery pack interface 5, the slow charging diode 903, the low-voltage positive power supply port 120 of the BMS controller 1, the low-voltage negative power supply port 121 of the BMS controller 1, and the battery pack slow charging negative power supply port 502 of the battery pack interface 5, forming a power supply circuit to the BMS controller 1. The slow charging positive power supply port 807 of the on-board charger 8 connects to the slow charging wake-up port 123 of the BMS controller 1 via the slow charging positive power supply port 503 of the battery pack interface 5, forming a slow charging activation circuit to activate the BMS controller for slow charging preparation. The subsequent control method after the BMS controller 1 is powered on and activated is the same as the control method in the manual switch 901 closed mode, and will not be described in detail here.

[0047] When battery discharge heating is required, the control methods for the electrical system of low-voltage battery packs in industrial vehicles include: Step 1: By default, manual switch 901 is in the closed state, and DC / DC module 2 supplies power to BMS controller 1; Step 2: After the vehicle is connected to high voltage, determine whether the heating function needs to be turned on. If the lowest battery temperature is <-10℃ and the average battery temperature is <0℃, turn on the heating function; Step 3: BMS controller 1 will control heating positive relay 904 and heating negative relay 907 to execute closing commands through heating positive relay control 111 and heating negative relay control 112 respectively. If the high voltage acquisition port HV G4 (105) detects that the voltage of HV G4 at the back end of the heating negative relay is close to that of the battery pack negative terminal voltage HV G0 (generally the difference is ±5% (TBD)), the heating negative relay 907 is considered to be closed. If the high voltage acquisition port HV P6 (109) detects that the voltage of HV P6 at the back end of the heating positive relay 904 is close to that of the battery pack positive terminal voltage HV P1 (generally the difference is ±5% (TBD)), the heating positive relay 904 is considered to be closed.

[0048] Step 4: During the heating process, the heating current flows from the positive terminal 401 of the lithium battery pack 4 → current acquisition module 3 → heating positive relay 904 → heating fuse 905 → heating film 906 → heating negative relay 907 → main circuit fuse 920 → negative terminal 403 of the lithium battery pack 4; among them, the heating fuse 905 prevents the heating current from overcurrent and protects the heating film and battery. Step 5: If the battery's lowest temperature is >0℃, turn off the heating function; Step 6: BMS controller 1 will control heating positive relay 904 and heating negative relay 907 to execute disconnect commands through heating positive relay control 111 and heating negative relay control 112 respectively. If the high voltage acquisition port HV G4 105 detects that the HV G4 voltage value at the rear end of heating negative relay 907 is not within the range of [battery pack negative terminal voltage HV G0*(1-5%(TBD)), battery pack positive terminal voltage HV G0*(1+5%(TBD))], it is determined that heating negative relay 907 has been disconnected. If the high voltage acquisition port HV P6 109 detects that the HV P6 voltage value at the rear end of heating positive relay 904 is not within the range of [battery pack negative terminal voltage HV P1*(1-5%(TBD)), battery pack positive terminal voltage HV P1*(1+5%(TBD))], it is determined that heating positive relay 904 has been disconnected.

[0049] Step 7: Discharge heating ends.

[0050] When fast charging and heating of the battery are required, the control methods for the electrical system of the low-voltage battery pack in industrial vehicles include: Step 1: With manual switch 901 in the closed state, DC / DC module 2 is working normally to provide constant power to BMS controller 1; Step 2: If the battery temperature is less than 0°C before charging begins, turn on the charging station to heat the battery pack. Once the temperature reaches a certain threshold, start charging the battery. Step 3: BMS controller 1 controls fast charging positive relay 915 and fast charging negative relay 910 to execute closing commands through fast charging positive relay control 119 and fast charging negative relay control 118, respectively. If the voltage at high voltage acquisition port HV G1 108 is close to the battery pack negative terminal voltage HV G0 (generally the difference is ±5% (TBD)), fast charging negative relay 910 is considered to have closed successfully; if the voltage at high voltage acquisition port HV P2 103 is close to the battery pack positive terminal voltage HV P1 (generally the difference is ±5% (TBD)), fast charging positive relay 915 is considered to have closed successfully. Step 4: BMS controller 1 controls heating positive relay 904 and heating negative relay 907 to execute closing commands through heating positive relay control 111 and heating negative relay control 112, respectively. If the high voltage acquisition port HV G4 105 detects that the voltage of HV G4 at the rear end of the heating negative relay is close to that of the battery pack negative terminal voltage HV G0 (generally the difference is ±5% (TBD)), the heating negative relay 907 is considered to have closed successfully. If the high voltage acquisition port HV P6 109 detects that the voltage of HV P6 at the rear end of the heating positive relay 904 is close to that of the battery pack positive terminal voltage HV P1 (generally the difference is ±5% (TBD)), the heating positive relay 904 is considered to have closed successfully.

[0051] Step 5: In charging mode, request constant current charging mode, charging current is 20A (TBD), voltage is requested to be greater than (battery pack voltage + 2)V; at this time, the current does not flow into battery pack 4, but only flows to heating film 906 to heat battery pack 4.

[0052] Step 6: Continuously monitor the heating status. If the average temperature of battery pack 4 is >5℃ and the minimum temperature is >0℃ for 1 minute, then turn off the heating and start the pure charging mode.

[0053] Step 7: BMS controller 1 controls heating positive relay 904 and heating negative relay 907 to execute disconnect commands via heating positive relay control 111 and heating negative relay control 112, respectively. If the high-voltage acquisition port HV G4 105 detects that the HV G4 voltage value at the rear end of heating negative relay 907 is not within the range of [battery pack negative terminal voltage HV G0*(1-5%(TBD)), battery pack positive terminal voltage HV G0*(1+5%(TBD))], it is determined that heating negative relay 907 has been disconnected. If the high-voltage acquisition port HV P6 109 detects that the HV P6 voltage value at the rear end of heating positive relay 904 is not within the range of [battery pack negative terminal voltage HV P1*(1-5%(TBD)), battery pack positive terminal voltage HV P1*(1+5%(TBD))], it is determined that heating positive relay 904 has been disconnected.

[0054] Step 8: After the charging and heating process is complete, begin charging. Finally, follow the charging procedure for the next steps.

[0055] When slow charging and heating of the battery are required, the control methods for the electrical system of the low-voltage battery pack in industrial vehicles include: Step 1: With manual switch 901 in the closed state, DC / DC module 2 is working normally to provide constant power to BMS controller 1; Step 2: If the battery temperature is less than 0°C before charging begins, turn on the charger to heat the battery pack. Once the temperature reaches a certain threshold, start charging the battery. Step 3: BMS controller 1 controls slow charging positive relay 911 and slow charging negative relay 908 to execute closing commands through slow charging positive relay control 116 and slow charging negative relay control 117, respectively. If the voltage at high voltage acquisition port HV G3 106 is close to the battery pack negative terminal voltage HV G0 (generally the difference is ±5% (TBD)), the slow charging negative relay 908 is considered to have closed successfully; if the voltage at high voltage acquisition port HV P5 110 is close to the battery pack positive terminal voltage HV P1 (generally the difference is ±5% (TBD)), the slow charging positive relay 911 is considered to have closed successfully. Step 4: BMS controller 1 controls heating positive relay 904 and heating negative relay 907 to execute closing commands through heating positive relay control 111 and heating negative relay control 112, respectively. If the high voltage acquisition port HV G4 105 detects that the voltage of HV G4 at the rear end of the heating negative relay is close to that of the battery pack negative terminal voltage HV G0 (generally the difference is ±5% (TBD)), the heating negative relay 907 is considered to have closed successfully. If the high voltage acquisition port HV P6 109 detects that the voltage of HV P6 at the rear end of the heating positive relay 904 is close to that of the battery pack positive terminal voltage HV P1 (generally the difference is ±5% (TBD)), the heating positive relay 904 is considered to have closed successfully.

[0056] Step 5: In charging mode, request constant current charging mode, charging current is 20A (TBD), voltage is requested to be greater than (battery pack voltage + 2)V; at this time, the current does not flow into battery pack 4, but only flows to heating film 906 to heat battery pack 4.

[0057] Step 6: Continuously monitor the heating status. If the average temperature of battery pack 4 is >5℃ and the minimum temperature is >0℃ for 1 minute, then turn off the heating and start the pure charging mode.

[0058] Step 7: BMS controller 1 controls heating positive relay 904 and heating negative relay 907 to execute disconnect commands via heating positive relay control 111 and heating negative relay control 112, respectively. If the high-voltage acquisition port HV G4 105 detects that the HV G4 voltage value at the rear end of heating negative relay 907 is not within the range of [battery pack negative terminal voltage HV G0*(1-5%(TBD)), battery pack positive terminal voltage HV G0*(1+5%(TBD))], it is determined that heating negative relay 907 has been disconnected. If the high-voltage acquisition port HV P6 109 detects that the HV P6 voltage value at the rear end of heating positive relay 904 is not within the range of [battery pack negative terminal voltage HV P1*(1-5%(TBD)), battery pack positive terminal voltage HV P1*(1+5%(TBD))], it is determined that heating positive relay 904 has been disconnected.

[0059] Step 8: After the charging and heating process is complete, begin charging. Finally, follow the charging procedure for the next steps.

[0060] The control methods for abnormal reverse wake-up of the BMS by the battery pack when the vehicle is powered off include: Step 1: Close the manual switch, and the DC / DC module 2 provides constant power to the BMS controller 1; Step 2: After the vehicle has been in operation for the last time and is powered off, the BMS controller 1 enters a sleep state, i.e., a low-power mode. The AFE module, as part of the BMS, also enters a low-power SLEEP mode. The AFE acts as a "sentinel" and "messenger." When the AFE enters sleep mode, it continuously monitors abnormal conditions such as battery voltage / temperature. Step 3: If the battery voltage is lower than 2.5V (TBD), the AFE module will immediately wake up the AFE module from SLEEP mode and restore it to normal working state (e.g., enter READY mode) if it detects that the voltage change of the undervoltage pin exceeds the threshold (which can be set). The whole process is completed automatically by the hardware and does not require any intervention from the BMS controller 1. Step 4: After the AFE module is woken up, it will send an interrupt signal (a falling edge) to BMS controller 1 through its INTB pin. Step 5: The interrupt signal is transmitted to the interrupt pin of BMS controller 1; Step 6: BMS controller 1 is awakened by a hardware interrupt signal and exits sleep mode; Step 7: BMS controller 1 reinitializes SPI; Step 8: BMS controller 1 reads the AFE fault register via SPI; Step 9: BMS controller 1 analyzes the specific cause of the fault and executes the corresponding processing procedure. BMS controller 1 can command AFE to perform corresponding operations, such as restarting battery voltage monitoring and evaluating the system status to determine the next action. Step 10: BMS controller 1 wakes up VCU controller 923 using CAN communication. VCU controller 923 has CAN wake-up function. BMS controller 1 wakes up VCU by sending a specified CAN message through the vehicle CAN interface (vehicle CAN H509, vehicle CAN L510) on battery pack interface 5 and the vehicle CAN interface (vehicle CAN H924, vehicle CAN L925) on VCU controller 923. VCU controller 923 exits low power mode and enters normal operation mode.

[0061] Step 11: The VCU controller 923 will upload the fault information to the vehicle's instrument panel, cloud platform, or vehicle mobile APP to remind the owner or after-sales service provider to take appropriate measures in advance to avoid irreversible damage to the battery and shorten its lifespan.

[0062] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0063] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0064] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0065] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0066] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An electrical system for a low-voltage battery pack in an industrial vehicle, characterized in that, include: The battery pack (4), BMS controller (1), VCU controller (923) and DC / DC module (2) are connected to the BMS controller (1) via the vehicle CAN bus. The DC / DC input circuit is connected from the positive terminal (401) of the battery pack (4) through a manual switch (901), a DC / DC fuse, a DC / DC enable port (204), a DC / DC positive input port (203), a DC / DC negative input port (205), and a main circuit fuse (920) to the negative terminal (403) of the battery pack (4). The DC / DC output circuit includes a first DC / DC power supply branch, a second DC / DC power supply branch, and a DC / DC wake-up branch connected in parallel; The first DC / DC power supply branch is connected to the DC / DC negative output port (201) of the DC / DC module (2) via the DC / DC positive output port (202) of the DC / DC module (2), the low-voltage positive power supply port (120) of the BMS controller (1), and the low-voltage negative power supply port (121) of the BMS controller (1). The second DC / DC power supply branch is connected to the DC / DC negative output port (201) of the DC / DC module (2) via the DC / DC positive output port (202) of the battery pack interface (5), the low-voltage positive power supply port (927) of the VCU controller (923), the low-voltage negative power supply port (928) of the VCU controller (923), and the DC / DC negative power supply port (513) of the battery pack interface (5). The DC / DC wake-up branch is connected to the first end of the key switch (921) via the DC / DC positive output port (202) of the DC / DC module (2) and the DC / DC positive power supply port (501) of the battery pack interface (5); the second end of the key switch (921) is connected to the vehicle wake-up port (926) of the VCU controller (923), and is connected to the DC / DC wake-up port (124) of the BMS controller (1) via the auxiliary wake-up port (504) of the battery pack interface (5).

2. The low-voltage battery pack electrical system for industrial vehicles according to claim 1, characterized in that, Also includes: A fast charging dock (6) is used to connect to a charging pile (7). The fast charging dock (6) is connected to the BMS controller (1) via a charging CAN bus. The fast charging auxiliary circuit includes a fast charging auxiliary power supply branch and a fast charging auxiliary wake-up branch connected in parallel; The fast charging auxiliary power supply branch is connected to the fast charging negative power supply port (603) of the fast charging base (6) via the fast charging auxiliary diode (929), the low voltage positive power supply port (120) of the BMS controller (1), and the low voltage negative power supply port (121) of the BMS controller (1). The fast charging auxiliary wake-up branch route connects the fast charging positive power supply port (602) of the fast charging dock (6) to the fast charging negative power supply port (603) of the fast charging dock (6) via the fast charging positive activation port (134) and the fast charging negative activation port (135) of the BMS controller (1). The fast charging connection confirmation circuit is connected from the charging connection feedback port (601) of the fast charging socket to the charging connection confirmation port (133) of the BMS controller (1). The fast charging circuit is connected from the fast charging DC positive output port (101) of the fast charging socket (6) through the fast charging positive relay (915), the positive terminal (401) of the battery pack (4), the negative terminal (403) of the battery pack (4), and the fast charging negative relay (910) to the fast charging DC negative output port (102) of the fast charging socket (6); the fast charging positive relay (915) and the fast charging negative relay (910) are both connected to the BMS controller (1) for communication.

3. The low-voltage battery pack electrical system for industrial vehicles according to claim 2, characterized in that, Also includes: The fast charging temperature acquisition circuit is connected from the temperature detection port of the fast charging socket (6) to the temperature acquisition port of the BMS controller (1); The fast charging heating circuit is connected from the fast charging DC positive output port (101) of the fast charging socket (6) through the fast charging positive relay (915), the heating positive relay (904), the heating fuse (905), the heating film (906), the heating negative relay (907), and the fast charging negative relay (910) to the fast charging DC negative output port (102) of the fast charging socket (6).

4. The low-voltage battery pack electrical system for industrial vehicles according to claim 1, characterized in that, Also includes: The on-board charger (8) is used to connect to the mains power through the power plug (809), and the on-board charger (8) is connected to the BMS controller (1) through the charging CAN. The slow charging auxiliary circuit includes a slow charging auxiliary power supply branch and a slow charging auxiliary wake-up branch connected in parallel; The slow charging auxiliary power supply branch is connected from the slow charging positive power supply port (807) of the vehicle charger (8) through the slow charging positive power supply port (503) of the battery pack interface (5), the slow charging diode (903), the low voltage positive power supply port (120) of the BMS controller (1), the low voltage negative power supply port (121) of the BMS controller (1), and the battery pack slow charging negative power supply port (502) of the battery pack interface (5) to the charger slow charging negative power supply port (808) of the vehicle charger (8). The slow charging auxiliary wake-up branch is connected to the slow charging wake-up port (123) of the BMS controller (1) via the slow charging positive power supply port (807) of the vehicle charger (8) and the slow charging positive power supply port (503) of the battery pack interface (5). The slow charging circuit is connected from the slow charging DC positive output port (802) of the on-board charger (8) through the slow charging positive port (918) of the battery box, the slow charging positive relay (911), the positive terminal (401) of the battery pack (4), the negative terminal (403) of the battery pack (4), the slow charging negative relay (908), and the slow charging negative port (919) of the battery box to the slow charging DC negative output port (801) of the on-board charger (8); the slow charging positive relay (911) and the slow charging negative relay (908) are both connected to the BMS controller (1) in communication. The slow charging connection confirmation circuit is connected from the slow charging connection feedback port (505) of the battery pack interface (5) to the slow charging connection confirmation port (125) of the BMS controller (1). The slow charging control circuit is connected to the slow charging control port (126) of the BMS controller (1) via the slow charging signal input port (506) of the battery pack interface (5).

5. The low-voltage battery pack electrical system for industrial vehicles according to claim 4, characterized in that, Also includes: The slow charging heating circuit is connected from the slow charging DC positive output port (802) of the on-board charger (8) through the slow charging positive port (918) of the battery box, the slow charging positive relay (911), the heating positive relay (904), the heating fuse (905), the heating film (906), the heating negative relay (907), the slow charging negative relay (908), and the slow charging negative port (919) of the battery box to the slow charging DC negative output port (801) of the on-board charger (8).

6. The low-voltage battery pack electrical system for industrial vehicles according to claim 1, characterized in that, Also includes: The battery discharge circuit is formed by connecting the positive terminal (401) of the battery pack (4) to the negative terminal (403) of the battery pack (4) via the main positive relay (914), the positive discharge port (916) of the battery box, the negative discharge port (917) of the battery box, the main negative relay (909), and the main circuit fuse (920). The main positive relay (914) and the main negative relay (909) are both connected to the BMS controller (1) in communication. The battery pre-charging circuit is connected from the positive terminal (401) of the battery pack (4) through the pre-charging relay (912), the pre-charging resistor (913), the positive discharge port (916) of the battery box, the negative discharge port (917) of the battery box, the main negative relay (909), and the main circuit fuse (920) to the negative terminal (403) of the battery pack (4). The pre-charging relay (912) is communicatively connected to the BMS controller (1). The discharge heating circuit consists of the positive terminal (401) of the battery pack (4), the current acquisition module (3), the heating positive relay (904), the heating fuse (905), the heating film (906), the heating negative relay (907), and the main circuit fuse (920) connected to the negative terminal (403) of the battery pack (4).

7. A control method for an electrical system of a low-voltage battery pack for industrial vehicles, characterized in that, Based on the low-voltage battery pack electrical system for industrial vehicles according to claim 1, the control method includes: When the vehicle needs to be powered on at high voltage, the manual switch (901) is closed, the DC / DC input circuit is turned on, and the first DC / DC power supply branch supplies power to the BMS controller (1); after the key switch (921) is closed, the DC / DC wake-up branch is turned on, activating the BMS controller (1) and VCU controller (923) to work, and the second DC / DC power supply branch supplies power to the VCU controller (923); after the BMS controller (1) and VCU controller (923) are powered on and running, the VCU controller (923) sends a high voltage command to the BMS controller (1) through the vehicle CAN bus. After receiving the high voltage command, the BMS controller (1) performs a self-test. If there are no abnormalities in the self-test, it will proceed according to the VCU... The controller (923) sends a high-voltage command to control the battery pack (4) to perform the high-voltage process; the BMS controller (1) controls the main negative relay (909), pre-charge relay (912), and main positive relay (914) to close in sequence. After the main negative relay (909), pre-charge relay (912), and main positive relay (914) are all energized, the BMS controller (1) disconnects the pre-charge relay (912), and the high-voltage power-on is completed; if the BMS controller (1) detects that the main negative relay (909), pre-charge relay (912), and main positive relay (914) have a closing fault or the pre-charge relay (912) has an opening fault, the high-voltage power-on fails and the fault cause is uploaded to the management terminal through the vehicle CAN. When the vehicle needs to be powered down normally, the VCU controller (923) sends a high-voltage power-down command to the BMS controller (1) through the vehicle CAN. The BMS controller (1) first controls the main positive relay (914) to disconnect, and then controls the main negative relay (909) to disconnect. If the BMS controller (1) detects that the main positive relay (914) or the main negative relay (909) has a disconnection fault, the high-voltage power-down fails and the fault cause is uploaded to the management terminal through the vehicle CAN. When the BMS controller (1) detects a fault in the vehicle, it needs to perform an abnormal high-voltage power-off. The BMS controller (1) requests a high-voltage power-off control request from the VCU controller (923) via the vehicle CAN. After receiving the high-voltage power-off control request, the VCU controller (923) adjusts the vehicle to a safe operating condition according to preset rules. Then, the VCU controller (923) replies to the BMS controller (1) via the vehicle CAN with a high-voltage power-off permission command. The BMS controller (1) executes the abnormal high-voltage power-off process. If the BMS controller (1) does not receive a high-voltage power-off permission command from the VCU controller (923) within a preset time after requesting the high-voltage power-off control request, the abnormal high-voltage power-off process is automatically executed. The BMS controller (1) first controls the main positive relay (914) to disconnect, and then controls the main negative relay (909) to disconnect. If the BMS controller (1) detects a disconnection fault in the main positive relay (914) or the main negative relay (909), the high-voltage power-off fails and the fault cause is uploaded to the management terminal via the vehicle CAN.

8. A control method for an electrical system of a low-voltage battery pack for industrial vehicles, characterized in that, Based on the low-voltage battery pack electrical system for industrial vehicles according to claim 2, the control method includes: When the vehicle needs to be fast charged, if the manual switch (901) is closed, the first DC / DC power supply branch and the DC / DC wake-up branch are connected, and the BMS controller (1) is woken up and powered on. If the manual switch (901) is open, the charging gun of the charging pile (7) is inserted into the fast charging socket (6), the fast charging auxiliary power supply branch and the fast charging auxiliary wake-up branch are connected, and the BMS controller (1) is woken up and powered on. After the BMS controller (1) determines that the charging gun and the fast charging socket (6) are successfully connected through the fast charging connection confirmation circuit, the BMS controller (1) controls the fast charging positive relay (915) and the fast charging negative relay (910) to close to fast charge the battery pack (4). During the charging process, the BMS controller (1) and the fast charging socket (6) exchange charging data through the charging CAN. When charging ends normally or abnormally, the BMS controller (1) sends a fast charging stop request to the fast charging dock (6). After receiving the fast charging stop request, the fast charging dock (6) adjusts the charging current to a safe range according to the preset rules and replies to the BMS controller (1) with a fast charging stop instruction. After receiving the fast charging stop instruction, the BMS controller (1) controls the fast charging positive relay (915) and fast charging negative relay (910) to disconnect, and the fast charging ends.

9. A control method for an electrical system of a low-voltage battery pack for industrial vehicles, characterized in that, Based on the low-voltage battery pack electrical system for industrial vehicles according to claim 4, the control method includes: When the vehicle needs to be charged slowly, if the manual switch (901) is closed, the first DC / DC power supply branch and the DC / DC wake-up branch are connected, and the BMS controller (1) is woken up and powered on. If the manual switch (901) is open, the on-board charger (8) is connected to the mains power through the power plug (809), and the slow charging auxiliary power supply branch and the slow charging auxiliary wake-up branch are connected, and the BMS controller (1) is woken up and powered on. After the BMS controller (1) determines that the on-board charger (8) and the battery box are successfully connected through the slow charging connection confirmation circuit, it controls the slow charging positive relay (911) and the slow charging negative relay (908) to close to slowly charge the battery pack (4). During the charging process, the BMS controller (1) and the on-board charger (8) exchange charging data through the charging CAN. When charging ends normally or abnormally, the BMS controller (1) sends a slow charging stop request to the on-board charger (8). After receiving the slow charging stop request, the on-board charger (8) adjusts the charging current to a safe range according to the preset rules and replies to the BMS controller (1) with a slow charging stop instruction. After receiving the slow charging stop instruction, the BMS controller (1) controls the slow charging positive relay (911) and the slow charging negative relay (908) to disconnect, and the slow charging ends.

10. A control method for an electrical system of a low-voltage battery pack for industrial vehicles, characterized in that, Based on the low-voltage battery pack electrical system for industrial vehicles according to any one of claims 1-6, the control method includes: After the vehicle is turned off, the manual switch (901) is closed, the DC / DC input circuit is turned on, the first DC / DC power supply branch provides constant power to the BMS controller (1), the BMS controller (1) is in a sleep state, the AFE module of the BMS controller (1) is woken up when it detects an abnormality in the battery pack (4), the AFE module sends an interrupt signal to the BMS controller (1), the BMS controller (1) is woken up after receiving the interrupt signal, the BMS controller (1) reads the fault information of the AFE module and executes the corresponding processing program, the BMS controller (1) also uses the vehicle CAN to wake up the VCU controller (923), the VCU controller (923) enters the normal working mode, the VCU controller (923) uploads the fault information read by the BMS controller (1) to the management terminal.

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