A battery management system to prevent precharge short circuits

Abstract

A battery management system for preventing short circuits during pre-charge includes a main circuit module, a pre-charge module, and a short-circuit protection module. The pre-charge module includes MOSFETs Q65 and Q66. The main circuit module includes MOSFET Q64, a pre-charge resistor R231, and a main MOSFET group, with the pre-charge resistor R231 located between MOSFET Q64 and the main MOSFET group. The short-circuit protection module is connected to the main MOSFET group and includes an amplifier U25 and a comparator U26, connected in series. The amplifier U25 is located between the main MOSFET group and the comparator U26. By adding a short-circuit protection module during the pre-charge process of the battery management system, and by using the amplifier and comparator in the short-circuit protection module to respond to and detect short-circuit currents in the main circuit in a timely manner, short-circuit protection is effectively achieved, ensuring the normal operation of the system.

Description

Technical Field

[0001] This utility model relates to the field of battery management, specifically a battery management system for preventing precharge short circuits. Background Technology

[0002] The battery management system (BMS) uses a pre-charge MOSFET connected in series with a current-limiting resistor to form a temporary charging path, slowly charging the bus capacitor with a low current until the voltage reaches over 90% of the total battery voltage. This prevents the bus capacitor from experiencing surge currents of thousands of amperes due to voltage jumps when the high-voltage system is powered on, which could cause arcing damage to the main contactor, capacitors, and other components. It also protects the battery from high-current surges. Typically, during the pre-charging process at startup of the BMS, the load capacitor is charged through the pre-charge circuit before the main MOSFET closes to avoid high-current surges.

[0003] However, existing battery management systems cannot effectively protect against short circuits during pre-charging, making it difficult to accurately distinguish between normal pre-charging processes and short-circuit faults. This may lead to misjudgment or underjudgment of short-circuit faults, affecting the normal operation of the system. Utility Model Content

[0004] The purpose of this invention is to provide a battery management system that prevents precharge short circuits, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: In a first aspect, this application provides a battery management system for preventing pre-charge short circuits, including a main circuit module, a pre-charge module, and a short-circuit protection module. The pre-charge module includes MOSFET Q65 and MOSFET Q66. The main circuit module includes MOSFET Q64, a pre-charge resistor R231, and a main MOSFET group. One end of MOSFET Q66 is connected to MOSFET Q65, and one end of MOSFET Q64 is connected to MOSFET Q65, while the other end is connected to the pre-charge resistor R231. MOSFET Q65 is located between MOSFET Q64 and MOSFET Q66, and the pre-charge resistor R231 is located between MOSFET Q64 and the main MOSFET group. The short-circuit protection module is connected to the main MOSFET group and includes an amplifier U25 and a comparator U26. The amplifier U25 and comparator U26 are coupled together and located between the main MOSFET group and the comparator U26.

[0006] In one possible implementation, a voltage divider resistor R232 is provided between the MOSFET Q65 and the MOSFET Q64.

[0007] In one possible implementation, a resistor R181 is provided between the output terminal of the amplifier U25 and the non-inverting input terminal of the comparator U26, the non-inverting input terminal of the amplifier U25 is connected to a resistor R177, the inverting input terminal of the amplifier U25 is connected to a resistor R176, and a capacitor C128 is provided between the resistor R176 and the resistor R177.

[0008] In one possible implementation, the inverting input of the comparator U26 is connected to resistors R184 and R185 and capacitor C133, with capacitor C133 connected in parallel with resistor R185.

[0009] In one possible implementation, the output of the comparator U26 is connected to a resistor R187, and the end of the resistor R187 away from the comparator U26 is connected to a microcontroller.

[0010] In one possible implementation, the MOSFET Q65 is also connected to a resistor R233 and a capacitor C166, with the resistor R233 and capacitor C166 connected in parallel; the MOSFET Q66 is also connected to a resistor R234 and a capacitor C167, with the resistor R234 and capacitor C167 connected in parallel.

[0011] Based on the same inventive concept, in a second aspect, embodiments of this application provide a battery system, including the battery management system as described in the first aspect.

[0012] Based on the same inventive concept, in a third aspect, embodiments of this application provide an electrical device including a battery system as described in any embodiment of the first aspect.

[0013] Compared with the prior art, the present invention has the following advantages: By adding a short-circuit protection module during the pre-charging process of the battery management system, and by using the amplifier and comparator of the short-circuit protection module to respond to and detect the short-circuit current in the main circuit in a timely manner, short-circuit protection is effectively achieved, ensuring the normal operation of the system. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a circuit diagram of the pre-charge module of this utility model; Figure 3 This is a circuit diagram of the short-circuit protection module of this utility model; Figure 4 This is the circuit diagram of the main circuit module of this utility model. Detailed Implementation

[0015] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0016] like Figure 1-4 As shown, the system includes a main circuit module 10, a pre-charge module 20, and a short-circuit protection module 30. The pre-charge module 20 includes MOSFETs Q65 and Q66. The main circuit module 10 includes MOSFET Q64, a pre-charge resistor R231, and a main MOSFET group. One end of MOSFET Q66 is connected to MOSFET Q65, and one end of MOSFET Q64 is connected to MOSFET Q65, while the other end is connected to the pre-charge resistor R231. MOSFET Q65 is located between MOSFETs Q64 and Q66, and the pre-charge resistor R231 is located between MOSFET Q64 and the main MOSFET group. The short-circuit protection module 30 is connected to the main MOSFET group and includes an amplifier U25 and a comparator U26. The amplifier U25 and comparator U26 are coupled together and located between the main MOSFET group and the comparator U26. A resistor R181 is provided between the output terminal of amplifier U25 and the non-inverting input terminal of comparator U26. The non-inverting input terminal of amplifier U25 is connected to resistor R177, and the inverting input terminal of amplifier U25 is connected to resistor R176. A capacitor C128 is provided between resistors R176 and R177. The inverting input terminal of comparator U26 is connected to resistors R184 and R185, and capacitor C133, with capacitor C133 connected in parallel with resistor R185. The output terminal of comparator U26 is connected to resistor R187, and the end of resistor R187 furthest from comparator U26 is connected to a microcontroller.

[0017] A voltage divider resistor R232 is provided between MOSFET Q65 and MOSFET Q64. MOSFET Q65 is also connected to resistor R233 and capacitor C166, with resistor R233 and capacitor C166 connected in parallel. MOSFET Q66 is also connected to resistor R234 and capacitor C167, with resistor R234 and capacitor C167 connected in parallel. The voltage divider resistor R232 is used to limit the gate drive voltage of Q65.

[0018] When the battery management system is powered on, the microcontroller outputs a high level, pulling down MOSFET Q65 and causing MOSFET Q66 to close. MOSFET Q66 then enables the drive voltage for MOSFET Q64 in the main circuit module. During the main circuit closure, the pre-charge current is limited by the pre-charge resistor R231 to prevent large current surges. After pre-charging is complete, the main MOSFET group circuit is closed, shutting down the pre-charge circuit. In this invention, the main MOSFET group can consist of 10 MOSFET units. Figure 2 In this configuration, Q1 and Q2 form one MOSFET unit, and Q3 and Q4 form another. During pre-charging, the battery management system monitors the port voltage and compares the voltages using voltage divider resistors. If the port voltage does not rise continuously or the pre-charging efficiency does not reach 80% within 3 seconds, short-circuit protection is triggered. After pre-charging is complete, the main MOSFET group is closed. If there is still a large current surge, comparator U26 is used to detect whether there is a true short circuit and distinguish between a true short-circuit protection and insufficient pre-charge short-circuit protection.

[0019] Based on the same inventive concept, embodiments of this application also provide a battery system, including the aforementioned battery management system for preventing pre-charge short circuits. It is understood that the battery system has the beneficial effects of the battery management system for preventing pre-charge short circuits provided in the embodiments of this application. For details, please refer to the specific descriptions of the battery management system for preventing pre-charge short circuits in the above embodiments; these descriptions will not be repeated here.

[0020] Based on the same inventive concept, this application also provides an electrical device. The electrical device includes the aforementioned battery system. It is understood that the electrical device has the beneficial effects of the battery management system provided in the embodiments of this application. For details, please refer to the specific descriptions of the battery management system for preventing pre-charge short circuits in the above embodiments, which will not be repeated here.

[0021] In the description of this utility model, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", "left and right", "front and back", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A battery management system that prevents pre-charge shorting, the system comprising: The system includes a main circuit module, a pre-charge module, and a short-circuit protection module. The pre-charge module includes MOSFETs Q65 and Q66. The main circuit module includes MOSFET Q64, a pre-charge resistor R231, and a main MOSFET group. One end of MOSFET Q66 is connected to MOSFET Q65, and one end of MOSFET Q64 is connected to MOSFET Q65, while the other end is connected to the pre-charge resistor R231. MOSFET Q65 is located between MOSFETs Q64 and Q66, and the pre-charge resistor R231 is located between MOSFET Q64 and the main MOSFET group. The short-circuit protection module is connected to the main MOSFET group and includes an amplifier U25 and a comparator U26. The amplifier U25 and comparator U26 are coupled together and located between the main MOSFET group and the comparator U26.

2. The battery management system to prevent pre-charge short circuit of claim 1, wherein, A voltage divider resistor R232 is provided between the MOSFET Q65 and the MOSFET Q64.

3. The battery management system to prevent pre-charge short circuit of claim 1, wherein, A resistor R181 is provided between the output terminal of the amplifier U25 and the non-inverting input terminal of the comparator U26. The non-inverting input terminal of the amplifier U25 is connected to a resistor R177, and the inverting input terminal of the amplifier U25 is connected to a resistor R176. A capacitor C128 is provided between the resistor R176 and the resistor R177.

4. The battery management system to prevent pre-charge short circuit of claim 3, wherein, The inverting input of the comparator U26 is connected to resistors R184 and R185 and capacitor C133, with capacitor C133 connected in parallel with resistor R185.

5. The battery management system to prevent pre-charge short circuit of claim 4, wherein, The output of the comparator U26 is connected to the resistor R187, and the end of the resistor R187 away from the comparator U26 is connected to the microcontroller.

6. The shorted pre-charge prevention battery management system of claim 1, wherein, The MOSFET Q65 is also connected to a resistor R233 and a capacitor C166, with the resistor R233 and capacitor C166 connected in parallel; the MOSFET Q66 is also connected to a resistor R234 and a capacitor C167, with the resistor R234 and capacitor C167 connected in parallel.

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