A lithium battery pack management system self-powered protection device

Abstract

The utility model discloses a lithium battery group management system self -power protection device, including lithium battery group and lithium battery management system, be connected with starting switch, protection circuit and direct current DCDC converter between lithium battery group and lithium battery management system, the protection circuit includes the car relay J1 of always open, the magnetic latching relay J2 of always close, a plurality of partial pressure resistance and reset switch, when management system is through the detection, discovers single string lithium battery voltage deficiency, and control magnetic latching relay cuts off low -voltage power supply, avoids the irreversible damage of lithium battery group. Meanwhile, also solved the lithium battery group management system work problem of no external low -voltage power supply, through the power reduction self -power from lithium battery group, and can carry out self -protection, the property safety of vehicle personnel is protected to the maximum degree.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery protection technology, specifically to a self-powered protection device for a lithium battery pack management system. Background Technology

[0002] Currently, most vehicles equipped with a Battery Management System (BMS) rely on an external low-voltage battery (such as a 12V / 24V starting battery) to power the BMS and low-voltage electrical components. However, such external low-voltage power supply modules are generally absent in traditional engineering vehicles that primarily use lead-acid batteries. When these vehicles replace lead-acid batteries with lithium batteries, significant technical deficiencies are exposed:

[0003] Power supply conflict: When there is a lack of external low-voltage power, the lithium battery management system has difficulty starting up and maintaining operation on its own, which leads to the failure of core functions such as battery status monitoring and equalization management, affecting battery performance and lifespan.

[0004] Protection blind spot: If a single string of cells in a lithium battery pack experiences an abnormality such as undervoltage, the power supply circuit cannot be cut off in time due to unstable power supply or delayed response of the BMS. This can easily lead to over-discharge of the battery, causing irreversible damage such as plate damage and capacity decay, and even poses a risk of thermal runaway. Summary of the Invention

[0005] The purpose of this invention is to provide a self-powered protection device for a lithium battery pack management system to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a self-powered protection device for a lithium battery pack management system, comprising a lithium battery pack and a lithium battery management system, wherein a start switch, a protection circuit and a DC / DC converter are connected between the lithium battery pack and the lithium battery management system.

[0007] The protection circuit includes a normally open automotive relay J1, a normally closed magnetic latching relay J2, multiple voltage divider resistors, and a reset switch.

[0008] The lithium battery pack is connected in sequence to the protection circuit and the DC / DC converter. The DC / DC converter is connected to the lithium battery management system, and the lithium battery management system is connected to the vehicle relay J1.

[0009] Preferably, the plurality of voltage divider resistors include resistors R1, R2, R3, R4, R5, and R6; the resistors R3, R2, R1, R6, R5, and R4 are connected in series, one end of resistor R3 is connected to a start switch, the start switch is connected to a lithium battery pack, and one end of resistor R4 is connected to a reset switch.

[0010] Preferably, the magnetic latching relay J2 includes an A-end coil, a B-end coil, and a normally closed contact; the two ends of the normally closed contact are respectively connected to a start switch and a DC / DC converter; one end of the A-end coil and the B-end coil are connected and connected between resistor R4 and resistor R5; the other end of the B-end coil is connected to a reset switch.

[0011] Preferably, the vehicle relay J1 includes a coil and a normally open contact; the two ends of the normally open contact are respectively connected to the coil at end A and the DC / DC converter, and the coil is connected to the lithium battery management system.

[0012] Compared with existing technologies, the beneficial effects of this utility model are: when the management system detects insufficient voltage in a single lithium battery string, it controls the magnetic latching relay to cut off the low-voltage power supply, thus preventing irreversible damage to the lithium battery pack. Simultaneously, it solves the problem of operation of lithium battery pack management systems without external low-voltage power supply, by drawing power from the lithium battery pack, reducing the voltage, and providing self-power, while also enabling self-protection, maximizing the protection of vehicle and personal property safety. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the present invention; Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0015] Please see Figure 1 This utility model provides a technical solution: a self-powered protection device for a lithium battery pack management system, including a lithium battery pack and a lithium battery management system. A start switch, a protection circuit, and a DC / DC converter are connected between the lithium battery pack and the lithium battery management system. The lithium battery pack is used to provide the initial voltage, the DC / DC converter is used to convert the high voltage of the lithium battery pack into a low voltage and supply it to the lithium battery management system, and the start switch is used to control the initial power supply of the lithium battery pack to the subsequent circuits.

[0016] The protection circuit includes a normally open automotive relay J1, a normally closed magnetic latching relay J2, multiple voltage divider resistors, and a reset switch;

[0017] The lithium battery pack is connected in sequence to the protection circuit and the DC / DC converter. The DC / DC converter is connected to the lithium battery management system, and the lithium battery management system is connected to the vehicle relay J1.

[0018] like Figure 1As shown: Multiple voltage divider resistors, including resistors R1, R2, R3, R4, R5, and R6, are connected in series. One end of resistor R3 is connected to the start switch, which is connected to the lithium battery pack. One end of resistor R4 is connected to the reset switch. These resistors form a voltage divider circuit to divide the output voltage of the lithium battery pack, generating a control voltage signal compatible with the relay coil. Specifically, the end of resistor R3 furthest from resistor R2 is connected to the start switch, which is connected to the positive terminal of the lithium battery pack. The end of resistor R4 furthest from resistor R5 is connected to the reset switch.

[0019] like Figure 1 As shown: The magnetic latching relay J2 includes an A-terminal coil, a B-terminal coil, and a normally closed contact. The two ends of the normally closed contact are connected to the start switch and the DC / DC converter, respectively, maintaining a circuit in the initial state to ensure power supply during system startup. One end of the A-terminal coil and one end of the B-terminal coil are connected between resistors R4 and R5, and the other end of the B-terminal coil is connected to the reset switch. When the reset switch is closed, the B-terminal coil is energized to control the normally closed contact to reset to the closed state. When the A-terminal coil is energized, it controls the normally closed contact to open to disconnect the main circuit.

[0020] like Figure 1 As shown: The automotive relay J1 includes a coil and a normally open contact; the two ends of the normally open contact are connected to the coil at end A and the DC / DC converter, respectively, and the coil is connected to the lithium battery management system. When the lithium battery management system detects an abnormal state, it energizes the control coil to close the normally open contact, triggering the normally closed contact of the magnetic latching relay J2 to open, thus realizing the protection function.

[0021] Working principle: When the vehicle start switch is closed, the lithium battery pack voltage enters the DC / DC converter through the normally closed magnetic latching relay J2, and is converted into low-voltage electricity to supply the lithium battery management system for operation.

[0022] When the voltage of a single cell in the lithium battery pack is low, the lithium battery management system controls the normally open automotive relay J1 to output a pulse voltage to the coil at terminal A of the magnetic latching relay J2, causing the normally closed contact of the magnetic latching relay J2 to open and cut off the power supply to the load side of the lithium battery pack, thereby protecting the lithium battery pack.

[0023] When power restoration is needed, close the vehicle start switch and click the reset switch. The lithium battery voltage outputs a pulse voltage to terminal B of the magnetic latching relay J2 through the voltage divider resistor, causing the magnetic latching relay contacts to close again, thereby restoring the low-voltage power supply circuit.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A self-powered protection device for a lithium battery pack management system, comprising a lithium battery pack and a lithium battery management system, characterized in that: The lithium battery pack is connected to the lithium battery management system by a start switch, a protection circuit, and a DC / DC converter. The protection circuit includes a normally open automotive relay J1, a normally closed magnetic latching relay J2, multiple voltage divider resistors, and a reset switch. The lithium battery pack is connected in sequence to the protection circuit and the DC / DC converter. The DC / DC converter is connected to the lithium battery management system, and the lithium battery management system is connected to the vehicle relay J1.

2. The self-powered protection device for a lithium battery pack management system according to claim 1, characterized in that: The plurality of voltage divider resistors include resistors R1, R2, R3, R4, R5, and R6; The resistors R3, R2, R1, R6, R5, and R4 are connected in series. One end of resistor R3 is connected to a start switch, which is connected to the lithium battery pack. One end of resistor R4 is connected to a reset switch.

3. The self-powered protection device for a lithium battery pack management system according to claim 2, characterized in that: The magnetic latching relay J2 includes an A-end coil, a B-end coil, and normally closed contacts; The two ends of the normally closed contact are connected to the start switch and the DC / DC converter, respectively. One end of the A-end coil and the B-end coil are connected and connected between resistor R4 and resistor R5. The other end of the B-end coil is connected to the reset switch.

4. The self-powered protection device for a lithium battery pack management system according to claim 3, characterized in that: The automotive relay J1 includes a coil and normally open contacts; The two ends of the normally open contact are connected to the coil at end A and the DC / DC converter, respectively, and the coil is connected to the lithium battery management system.

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