A battery pack heating pre-charging control circuit and control method

Abstract

The application discloses a battery pack heating pre-charging control circuit and a control method, and relates to the field of battery management systems.The circuit comprises a battery pack, a heating film, a discharging switch, a first heating switch, a second heating switch, a pre-charging switch, a load / charger and a controller.When the pre-charging is started, the first heating switch and the pre-charging switch are closed to turn on the pre-charging circuit, and an improved pre-charging circuit is realized.When the pre-charging process is finished, the discharging switch is normally closed.When the heating is started, the first heating switch and the second heating switch are closed to turn on the heating circuit, and the heating circuit is realized.The pre-charging circuit mainly comprises the heating film and the pre-charging switch, and the role of the pre-charging resistor is replaced by the heating film.Because the resistance value of the heating film is smaller than that of the general pre-charging resistor, the energy loss is reduced, the heat generation is lowered, and the reliability of the battery pack system is improved.

Description

Technical Field

[0001] This application relates to the field of battery management systems, and in particular to a battery pack heating pre-charge control circuit and control method. Background Technology

[0002] With the rapid development of electric vehicles and energy storage systems, high-voltage battery packs are being used more and more widely. When connecting the battery pack to the system, the initial voltage of the capacitors is zero, and direct connection can cause a sudden surge of large current, potentially damaging the battery pack and system components. Therefore, the design of the pre-charging circuit has become one of the key technologies in battery management systems. Currently, the industry commonly uses methods such as resistor pre-charging and inductor pre-charging to alleviate this problem, but these methods each have their advantages and disadvantages, and a more efficient and reliable solution is urgently needed.

[0003] Existing precharge technologies mainly include two methods: resistive precharge and inductive precharge. Resistive precharge limits the current through a series resistor to achieve smooth charging, but the resistor generates heat and has low efficiency. Inductive precharge utilizes the characteristics of the inductor to limit the rate of current change, but it is larger and more expensive. In addition, there are some hybrid precharge schemes that combine the advantages of resistors and inductors, but these still have complexity and reliability issues.

[0004] The main drawbacks of resistor pre-charging are high energy loss and severe heat generation, which may lead to resistor aging or even failure with long-term use. Although inductor pre-charging can reduce energy loss, its size and cost limit its widespread application. Although the hybrid pre-charging scheme combines the advantages of resistors and inductors to some extent, the system is complex, has high maintenance costs, and its reliability is difficult to guarantee. Summary of the Invention

[0005] The purpose of this application is to provide a battery pack heating pre-charge control circuit and control method to reduce energy loss, reduce heat generation and improve system reliability.

[0006] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a battery pack heating pre-charge control circuit, including: a battery pack, a heating film, a discharge switch, a first heating switch, a second heating switch, a pre-charge switch, a load / charger, and a controller; The positive terminal of the battery pack, the discharge switch, and the positive terminal of the load / charger are connected in sequence; the negative terminal of the battery pack is connected to the negative terminal of the load / charger; the positive terminal of the battery pack, the first heating switch, the heating film, the second heating switch, and the negative terminal of the battery pack are connected in sequence; one end of the pre-charge switch is connected to the positive terminal of the load / charger; the other end of the pre-charge switch is connected to the connection end of the heating film and the second heating switch; The controller is connected to the discharge switch, the first heating switch, the second heating switch and the pre-charge switch respectively; the controller is used to control the opening or closing of the discharge switch, the first heating switch, the second heating switch and the pre-charge switch.

[0007] In one embodiment, the controller is used to: In pre-charge mode, the first heating switch and the pre-charge switch are closed to conduct the pre-charge circuit composed of the battery pack, the heating film, the first heating switch and the pre-charge switch, so as to pre-charge the large capacitor on the load / charger side by utilizing the resistance of the heating film. After the pre-charging process is completed, the discharge switch is closed to connect the main circuit; In heating mode, the first heating switch and the second heating switch are closed to conduct the heating circuit consisting of the battery pack, the heating film, the first heating switch and the second heating switch, so as to realize the heating function.

[0008] In one embodiment, the resistance of the heating film is less than the resistance of the pre-charge resistor.

[0009] In one embodiment, the heating film is used as a current-limiting element in pre-charge mode and as a heating element in heating mode.

[0010] Secondly, this application provides a battery pack heating pre-charge control method, which is applied to the aforementioned battery pack heating pre-charge control circuit, and includes: In pre-charge mode, the first heating switch and the pre-charge switch are closed to conduct the pre-charge circuit composed of the battery pack, the heating film, the first heating switch and the pre-charge switch, so as to pre-charge the large capacitor on the load / charger side by utilizing the resistance of the heating film. After the pre-charging process is completed, the discharge switch is closed to connect the main circuit; In heating mode, the first heating switch and the second heating switch are closed to conduct the heating circuit consisting of the battery pack, the heating film, the first heating switch and the second heating switch, so as to realize the heating function.

[0011] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a battery pack heating pre-charge control circuit and control method. The circuit includes: a battery pack, a heating film, a discharge switch, a first heating switch, a second heating switch, a pre-charge switch, a load / charger, and a controller. When pre-charging is initiated, the first heating switch and the pre-charge switch are closed to conduct the pre-charge circuit, realizing an improved pre-charge circuit. After the pre-charge process is completed, the discharge switch closes normally. When heating is initiated, the first heating switch and the second heating switch are closed to conduct the heating circuit, simultaneously realizing the heating circuit. The pre-charge circuit of this application mainly consists of a heating film and a pre-charge switch. The heating film replaces the pre-charge resistor. Since the resistance of the heating film is smaller than that of a typical pre-charge resistor, the pre-charge current is larger. For loads with large capacitors, this accelerates the pre-charge speed and shortens the pre-charge time; simplifies the pre-charge structure and saves production costs; avoids the problem of pre-charge resistor overheating and failure, and reduces safety hazards. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 For traditional pre-charging circuit diagrams; Figure 2 This is a circuit diagram of a battery pack heating precharge control circuit provided in one embodiment of this application. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] like Figure 1 As shown in the diagram, the battery pack system block diagram mainly consists of the battery pack, heating film, discharge switch, pre-charge resistor, pre-charge switch, load / charger, etc. The traditional pre-charge control circuit mainly consists of a pre-charge resistor and a pre-charge switch.

[0017] When precharging is initiated, the precharging switch is closed to activate the precharging circuit. After the precharging process is completed, the discharge switch closes normally. When the load has a large capacitor, traditional precharging circuits suffer from slow precharging speed and long precharging time, which can easily lead to overheating, failure, or precharging failure, posing safety risks.

[0018] This application mainly relates to the field of battery management system technology, especially battery pack pre-charging technology in off-road vehicles and energy storage systems, and is mainly applicable to scenarios such as off-road vehicles and energy storage systems that require pre-charging of large capacitor loads.

[0019] In one exemplary embodiment, such as Figure 2 As shown, a battery pack heating pre-charge control circuit is provided, including: a battery pack, a heating film, a discharge switch, a first heating switch (heating switch 1), a second heating switch (heating switch 2), a pre-charge switch, a load / charger, and a controller.

[0020] The positive terminal (B+) of the battery pack, the discharge switch, and the positive terminal (P+ / C+) of the load / charger are connected in sequence; the negative terminal (B-) of the battery pack is connected to the negative terminal (P- / C-) of the load / charger; the positive terminal of the battery pack, the first heating switch, the heating film, the second heating switch, and the negative terminal of the battery pack are connected in sequence; one end of the pre-charge switch is connected to the positive terminal of the load / charger; the other end of the pre-charge switch is connected to the connection end of the heating film and the second heating switch.

[0021] The controller is connected to the discharge switch, the first heating switch, the second heating switch and the pre-charge switch respectively; the controller is used to control the opening or closing of the discharge switch, the first heating switch, the second heating switch and the pre-charge switch.

[0022] In one embodiment, the controller is used to: In pre-charge mode, the first heating switch and the pre-charge switch are closed to conduct the pre-charge circuit consisting of the battery pack, the heating film, the first heating switch and the pre-charge switch, so as to pre-charge the large capacitor on the load / charger side by utilizing the resistance of the heating film.

[0023] After the pre-charging process is completed, the discharge switch is closed to connect the main circuit.

[0024] In heating mode, the first heating switch and the second heating switch are closed to conduct the heating circuit consisting of the battery pack, the heating film, the first heating switch and the second heating switch, so as to realize the heating function.

[0025] In one embodiment, the resistance of the heating film is less than the resistance of the pre-charge resistor.

[0026] In one embodiment, the heating film is used as a current-limiting element in pre-charge mode and as a heating element in heating mode.

[0027] The battery pack heating pre-charge control circuit provided in this application mainly consists of a battery pack, a heating film, a discharge switch, a pre-charge switch, and a load / charger. The pre-charge circuit of this application mainly consists of a heating film and a pre-charge switch. The heating film replaces the pre-charge resistor, simplifying the pre-charge circuit structure while simultaneously realizing the heating circuit.

[0028] When pre-charging is initiated, heating switch 1 and pre-charging switch are closed to activate the pre-charging circuit, thus implementing the improved pre-charging circuit. After the pre-charging process is completed, the discharge switch closes normally. When heating is initiated, heating switch 1 and heating switch 2 are closed to activate the heating circuit, thus implementing the heating circuit.

[0029] Working principle: When the normal discharge process is started, first close the heating switch 1 and the pre-charge switch 1000ms and then open them, then close the discharge switch to start the discharge circuit. When the normal heating process is started, closing heating switch 1 and heating switch 2 connects the heating film circuit and activates the heating function.

[0030] This application makes structural improvements and optimizations to the pre-charge circuit. Since the resistance of the heating film is smaller than that of a typical pre-charge resistor, the pre-charge current is larger. For loads with large capacitors, this accelerates the pre-charge speed and shortens the pre-charge time. It also simplifies the pre-charge structure, saves production costs, avoids the problem of pre-charge resistor overheating and failure, and reduces safety hazards.

[0031] In one exemplary embodiment, this application provides a battery pack heating pre-charge control method, which is applied to the aforementioned battery pack heating pre-charge control circuit. The battery pack heating pre-charge control method includes: In pre-charge mode, the first heating switch and the pre-charge switch are closed to conduct the pre-charge circuit consisting of the battery pack, the heating film, the first heating switch and the pre-charge switch, so as to pre-charge the large capacitor on the load / charger side by utilizing the resistance of the heating film.

[0032] After the pre-charging process is completed, the discharge switch is closed to connect the main circuit.

[0033] In heating mode, the first heating switch and the second heating switch are closed to conduct the heating circuit consisting of the battery pack, the heating film, the first heating switch and the second heating switch, so as to realize the heating function.

[0034] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0035] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A battery pack heating pre-charge control circuit, characterized in that, include: Battery pack, heating film, discharge switch, first heating switch, second heating switch, pre-charge switch, load / charger, and controller; The positive terminal of the battery pack, the discharge switch, and the positive terminal of the load / charger are connected in sequence; the negative terminal of the battery pack is connected to the negative terminal of the load / charger; the positive terminal of the battery pack, the first heating switch, the heating film, the second heating switch, and the negative terminal of the battery pack are connected in sequence; one end of the pre-charge switch is connected to the positive terminal of the load / charger; the other end of the pre-charge switch is connected to the connection end of the heating film and the second heating switch; The controller is connected to the discharge switch, the first heating switch, the second heating switch and the pre-charge switch respectively; the controller is used to control the opening or closing of the discharge switch, the first heating switch, the second heating switch and the pre-charge switch.

2. The battery pack heating pre-charge control circuit according to claim 1, characterized in that, The controller is used for: In pre-charge mode, the first heating switch and the pre-charge switch are closed to conduct the pre-charge circuit composed of the battery pack, the heating film, the first heating switch and the pre-charge switch, so as to pre-charge the large capacitor on the load / charger side by utilizing the resistance of the heating film. After the pre-charging process is completed, the discharge switch is closed to connect the main circuit; In heating mode, the first heating switch and the second heating switch are closed to conduct the heating circuit consisting of the battery pack, the heating film, the first heating switch and the second heating switch, so as to realize the heating function.

3. The battery pack heating pre-charge control circuit according to claim 1, characterized in that, The resistance of the heating film is less than that of the pre-charge resistor.

4. The battery pack heating pre-charge control circuit according to claim 1, characterized in that, The heating film is used as a current limiting element in pre-charge mode and as a heating element in heating mode.

5. A method for controlling pre-charge heating of a battery pack, characterized in that, The battery pack heating pre-charge control method is applied to the battery pack heating pre-charge control circuit according to any one of claims 1-4, and the battery pack heating pre-charge control method includes: In pre-charge mode, the first heating switch and the pre-charge switch are closed to conduct the pre-charge circuit composed of the battery pack, the heating film, the first heating switch and the pre-charge switch, so as to pre-charge the large capacitor on the load / charger side by utilizing the resistance of the heating film. After the pre-charging process is completed, the discharge switch is closed to connect the main circuit; In heating mode, the first heating switch and the second heating switch are closed to conduct the heating circuit consisting of the battery pack, the heating film, the first heating switch and the second heating switch, so as to realize the heating function.

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