A battery access control device and a battery access control method

Abstract

The present invention belongs to the technical field of BMS control systems, and specifically relates to a control device for battery access and a control method thereof, wherein the control device comprises a BMS main control circuit, a charge and discharge switch module, an access detection circuit, a separation switch and an application system connector, wherein the BMS main control circuit can monitor the working state of the battery, and monitor the access state of the application system through the access detection circuit, and at the same time control the charging, discharging and pre-discharging of the battery through the charge and discharge switch module, and control the connection of the pins of the system connector through the separation switch; thus, the control device and the control method thereof of the present invention can provide a small current pre-charging for the capacitor of the application system when the application system is accessed, so as to avoid the generation of surge current, and at the same time further realize the high-power discharge of the battery system by controlling the separation, so as to meet the reliable access of the high-power battery system and the large-input-capacitor application system.

Description

Technical Field

[0001] The present invention belongs to the technical field of BMS control systems, and in particular relates to a battery access control device and a control method thereof. Background Art

[0002] The battery management system (BMS) is an electronic system used to monitor and manage battery packs. It protects batteries from damage, prolongs their service life, and ensures the stability and safety of the entire battery system by monitoring battery voltage, current, temperature and other parameters. Existing battery application systems have large input capacitance and operating power, and lack communication pins. The battery management system cannot communicate directly with the application system to detect the connection between the battery and the application system, resulting in a large surge current when the application system is connected. The large surge current causes arcing at the contacts of the battery and system connectors, causing oxidation, increasing the risk of poor contact between the connectors and connector fire, and may even damage the BMS of the battery system. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defect in the prior art that the battery management system cannot directly communicate with the application system, resulting in a large surge current when the application system is connected, thereby causing damage to the battery management system, thereby providing a battery access control device and a control method thereof.

[0004] A battery access control device, comprising a BMS main control circuit, a charge and discharge switch module, an access detection circuit, a separation switch, and an application system connector;

[0005] The BMS main control circuit is connected to the battery and is used to monitor the working status of the battery;

[0006] The charge and discharge switch module is connected in series to the negative electrode of the battery, connected and controlled by the BMS main control circuit, and is used to control the charging, discharging and pre-discharging of the battery according to the working state of the battery and the access state of the application system;

[0007] The application system connector includes a positive pin and a negative pin, which are used to connect the application system; the positive pin is connected to the positive electrode of the battery, and the negative pin includes a first negative pin and a second negative pin, the first negative pin is connected to the negative electrode of the battery through the separation switch and the charge and discharge switch module in sequence, and the second negative pin is connected to the negative electrode of the battery through the charge and discharge switch module;

[0008] The separation switch is connected by the BMS main control circuit and controls the switch according to the working state of the battery and the access state of the application system;

[0009] The access detection circuit is connected to the first cathode pin, and is used to detect the access status of the application system and output it to the BMS main control circuit.

[0010] Furthermore, the charge and discharge switch module includes a charge switch, a discharge switch and a pre-discharge current limiting circuit; the charge switch and the discharge switch are connected in series to the negative electrode of the battery; the pre-discharge current limiting circuit is connected in parallel to the discharge switch; and the BMS main control circuit is respectively connected to and controls the charge switch, the discharge switch and the pre-discharge current limiting circuit.

[0011] Furthermore, the pre-discharge current limiting circuit includes a pre-discharge switch and a current limiting resistor, wherein the pre-discharge switch is connected in series with the current limiting resistor and in parallel with the discharge switch.

[0012] Furthermore, the access detection circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor, the first end of the first voltage-dividing resistor is connected to a DC power supply, the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor, and the second end of the second voltage-dividing resistor is connected to the first negative pin; the BMS main control circuit is connected to the second end of the first voltage-dividing resistor for obtaining a voltage-dividing signal.

[0013] Furthermore, the positive pin includes a first positive pin and a second positive pin, and the first positive pin is short-circuited with the second positive pin.

[0014] Furthermore, it also includes a current sensor, which is connected between the battery and the charge and discharge switch module, and the BMS main control circuit is connected to the current sensor to obtain a current signal.

[0015] Furthermore, the charging switch, discharging switch, pre-discharging switch and separation switch are all MOS tubes.

[0016] Furthermore, the BMS main control circuit includes a programmable logic controller.

[0017] A method for controlling battery access, wherein the battery access is controlled by the above-mentioned battery access control device, wherein the BMS main control circuit controls the on-off of the pre-discharge switch and the charging switch according to the working state of the battery, controls the on-off of the discharge switch according to the capacitor voltage of the application system, and controls the on-off of the separation switch according to the input current of the battery.

[0018] Furthermore, the battery access control method includes the following steps:

[0019] Step S1: the BMS main control circuit collects information about the battery and determines the working status of the battery;

[0020] Step S2: the BMS main control circuit controls the pre-discharge switch and the charge switch to be turned on and the separation switch to be turned off according to the working state of the battery;

[0021] Step S3: connecting the application system to the application system connector, the BMS main control circuit detecting the capacitor voltage of the system application, and controlling the discharge switch to be turned on when the capacitor voltage is greater than a preset voltage threshold;

[0022] Step S4: the BMS main control circuit detects the discharge current of the battery, and controls the separation switch to be turned on when the discharge current is greater than a preset current threshold.

[0023] Beneficial effect: The present invention discloses a control device for battery access and a control method thereof, the control device comprising a BMS main control circuit, a charge and discharge switch module, an access detection circuit, a separation switch and an application system connector, the BMS main control circuit being able to monitor the working status of the battery, and monitor the access status of the application system through the access detection circuit, while controlling the charging, discharging and pre-discharging of the battery through the charge and discharge switch module, and controlling the connection of the pins of the system connector through the separation switch; thus, the control device and the control method thereof of the present invention can provide a small current pre-charging for the capacitor of the application system when the application system is accessed, thereby avoiding the generation of surge current, and at the same time further realizing high-power discharge of the battery system by controlling the separation switch, thereby meeting the reliable access of the high-power battery system and the large-input capacitance application system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the overall system structure of the present invention;

[0026] Figure 2 It is a schematic block diagram of the control method of the present invention. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0028] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] Embodiment 1:

[0031] Reference Figure 1As shown, this embodiment discloses a control device for battery access, including a BMS main control circuit, a charge and discharge switch module, an access detection circuit, a separation switch, and an application system connector; the BMS main control circuit is connected to the battery to monitor the working state of the battery; the charge and discharge switch module is connected in series to the negative electrode of the battery, connected and controlled by the BMS main control circuit, and is used to control the charging, discharging and pre-discharging of the battery according to the working state of the battery and the access state of the application system; the application system connector includes a positive pin and a negative pin, which are used to connect the application system; the positive pin is connected to the positive electrode of the battery, and the negative pin includes a first negative pin and a second negative pin, the first negative pin is connected to the negative electrode of the battery through the separation switch and the charge and discharge switch module in sequence, and the second negative pin is connected to the negative electrode of the battery through the charge and discharge switch module; the separation switch is connected by the BMS main control circuit, and controls the switch according to the working state of the battery and the access state of the application system; the access detection circuit is connected to the first negative pin, which is used to detect the access state of the application system and control and output to the BMS main control circuit.

[0032] The present embodiment discloses a control device for battery access, which can monitor the working status of the battery through the BMS main control circuit, and monitor the access status of the application system through the access detection circuit, and control the charging, discharging and pre-discharging of the battery through the charge and discharge switch module, and control the connection of the system connector pins through the separation switch; thus, the control device and the control method of the present invention can provide a small current pre-charging for the capacitor of the application system when the application system is accessed, avoiding the generation of surge current, and further realize the high-power discharge of the battery system by controlling the separation switch, so as to meet the reliable access of the high-power battery system and the large input capacitance application system.

[0033] In this embodiment, the charge and discharge switch module includes a charge switch, a discharge switch and a pre-discharge current limiting circuit; the charge switch and the discharge switch are connected in series to the negative electrode of the battery; the pre-discharge current limiting circuit is connected in parallel to the discharge switch; the BMS main control circuit is respectively connected to and controls the charge switch, the discharge switch and the pre-discharge current limiting circuit. Specifically, the pre-discharge current limiting circuit includes a pre-discharge switch and a current limiting resistor, the pre-discharge switch is connected in series with the current limiting resistor and in parallel with the discharge switch. As a preferred embodiment of this embodiment, the charge switch, the discharge switch and the pre-discharge switch are all MOS tubes, and the gate is connected to the BMS main control circuit, so that the switch can be directly and effectively driven through the control pin of the BMS main control circuit. In some other embodiments of the present invention, the charge switch, the discharge switch and the pre-discharge switch can be other electronic switches, including triodes or relays. In some embodiments of the present invention, the pre-discharge current limiting circuit is a combination of a pre-discharge switch and other current limiting circuits, and the battery current flows through the current limiting circuit through the pre-discharge switch.

[0034] In some embodiments of the present invention, the access detection circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor, wherein the first end of the first voltage-dividing resistor is connected to a DC power supply, the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor, and the second end of the second voltage-dividing resistor is connected to the first negative electrode pin; the BMS main control circuit is connected to the second end of the first voltage-dividing resistor to obtain a voltage-dividing signal. In other embodiments of the present invention, the access detection circuit may be another level detection circuit, which obtains the voltage signal of the first negative electrode pin and inputs it into the BMS main control circuit.

[0035] In this embodiment, the positive pin includes a first positive pin and a second positive pin, and the first positive pin is short-circuited with the second positive pin to provide power to meet the high requirements of the application system.

[0036] As a further improvement of this embodiment, a current sensor is further included, the current sensor is connected between the battery and the charge and discharge switch module, the BMS main control circuit is connected to the current sensor, and is used to obtain a current signal. The current sensor obtains the output current of the battery and provides a reference for the BMS main control circuit to control the switch.

[0037] The separation switch is an electronic switch, which may be a triode, a relay, a MOS tube or other electronic switches. As a preferred embodiment of the present invention, the separation switch is a MOS tube.

[0038] In this embodiment, the BMS main control circuit includes a programmable logic controller, which can change its function through software programming, can provide flexible adjustment for battery output control through programming, and has high reliability and durability in industrial environments. In other embodiments of the present invention, the BMS main control circuit can also be one or more combinations of a single-chip microcomputer, a central processing unit, a field programmable gate array, etc.

[0039] Embodiment 2:

[0040] Reference Figure 2 As shown, this embodiment discloses a battery access control method, in which the battery access is controlled by the battery access control device described in Example 1, and the BMS main control circuit controls the on-off of the pre-discharge switch and the charging switch according to the working state of the battery, controls the on-off of the discharge switch according to the capacitor voltage of the application system, and controls the on-off of the separation switch according to the input current of the battery.

[0041] In this embodiment, the battery access control method includes the following steps:

[0042] Step S1: the BMS main control circuit collects information about the battery and determines the working status of the battery;

[0043] Step S2: the BMS main control circuit controls the pre-discharge switch and the charge switch to be turned on and the separation switch to be turned off according to the working state of the battery;

[0044] Step S3: connecting the application system to the application system connector, the BMS main control circuit detecting the capacitor voltage of the system application, and controlling the discharge switch to be turned on when the capacitor voltage is greater than a preset voltage threshold;

[0045] Step S4: the BMS main control circuit detects the discharge current of the battery, and controls the separation switch to be turned on when the discharge current is greater than a preset current threshold.

[0046] Working principle: When the application system is not connected, the BMS main control circuit collects the information of the battery, including the cell voltage, current, temperature, etc., and calculates and determines the status of the battery system. If the working status of the battery is normal, the pre-discharge switch is turned on. At this time, the separation switch, the charging switch and the discharge switch are turned off.

[0047] When the application system is connected through the application system connector, the first negative pin and the second negative pin are short-circuited in the application system, and the BMS main control circuit detects a high level through the connection detection circuit, and determines that the application system has been connected. At this time, the application system is powered by the pre-discharge current limiting circuit to charge the capacitor of the application system with a small current, thereby realizing surge-free current insertion.

[0048] When the BMS main control circuit detects that the capacitor voltage of the application system reaches a preset voltage threshold, it controls the charging switch and the discharging switch to be turned on, and the battery provides surge-free current power supply to the application system through the charging switch and the discharging switch.

[0049] When the BMS main control circuit detects the discharge current of the battery through the current sensor, and the current of the battery through the pre-discharge current limiting circuit is greater than the preset current threshold, the separation switch is controlled to be turned on, so that the battery simultaneously powers the application system through the first negative pin and the second negative pin, effectively supporting the high-power discharge of the battery and avoiding the situation where the application system is connected to a single pin with insufficient power.

[0050] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0051] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A battery access control device, characterized in that: Including BMS main control circuit, charge and discharge switch module, access detection circuit, separation switch, and application system connector; The BMS main control circuit is connected to the battery and is used to monitor the working status of the battery; The charge and discharge switch module is connected in series to the negative electrode of the battery, connected and controlled by the BMS main control circuit, and is used to control the charging, discharging and pre-discharging of the battery according to the working state of the battery and the access state of the application system; The application system connector includes a positive pin and a negative pin, which are used to connect the application system; the positive pin is connected to the positive electrode of the battery, and the negative pin includes a first negative pin and a second negative pin, the first negative pin is connected to the negative electrode of the battery through the separation switch and the charge and discharge switch module in sequence, and the second negative pin is connected to the negative electrode of the battery through the charge and discharge switch module; The separation switch is connected by the BMS main control circuit and controls the switch according to the working state of the battery and the access state of the application system; The BMS main control circuit is used to detect the discharge current of the battery, and when the discharge current is greater than a preset current threshold, the separation switch is controlled to be turned on, and the first negative electrode pin and the second negative electrode pin are short-circuited in the application system, so that the battery simultaneously supplies power to the application system through the first negative electrode pin and the second negative electrode pin; The access detection circuit is connected to the first cathode pin, and is used to detect the access status of the application system and output it to the BMS main control circuit.

2. A battery access control device according to claim 1, characterized in that: The charge and discharge switch module includes a charge switch, a discharge switch and a pre-discharge current limiting circuit; the charge switch and the discharge switch are connected in series to the negative electrode of the battery; the pre-discharge current limiting circuit is connected in parallel to the discharge switch; the BMS main control circuit is respectively connected to and controls the charge switch, the discharge switch and the pre-discharge current limiting circuit.

3. A battery access control device according to claim 2, characterized in that: The pre-discharge current limiting circuit comprises a pre-discharge switch and a current limiting resistor. The pre-discharge switch is connected in series with the current limiting resistor and in parallel with the discharge switch.

4. A battery access control device according to claim 1, characterized in that: The access detection circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor, wherein a first end of the first voltage-dividing resistor is connected to a DC power supply, a second end of the first voltage-dividing resistor is connected to a first end of the second voltage-dividing resistor, and a second end of the second voltage-dividing resistor is connected to the first negative electrode pin; the BMS main control circuit is connected to the second end of the first voltage-dividing resistor for obtaining a voltage-dividing signal.

5. A battery access control device according to claim 1, characterized in that: The positive pin includes a first positive pin and a second positive pin, and the first positive pin is short-circuited with the second positive pin.

6. A battery access control device according to claim 1, characterized in that: It also includes a current sensor, which is connected between the battery and the charge and discharge switch module. The BMS main control circuit is connected to the current sensor to obtain a current signal.

7. A battery access control device according to claim 3, characterized in that: The charging switch, discharging switch, pre-discharging switch and separation switch are all MOS tubes.

8. A battery access control device according to claim 1, characterized in that: The BMS main control circuit includes a programmable logic controller.

9. A battery access control method, characterized in that: The battery access is controlled by the battery access control device according to claim 3, and the BMS main control circuit controls the on-off of the pre-discharge switch and the charging switch according to the working state of the battery, controls the on-off of the discharge switch according to the capacitor voltage of the application system, and controls the on-off of the separation switch according to the input current of the battery.

10. A battery access control method according to claim 9, characterized in that: The battery access control method comprises the following steps: Step S1: the BMS main control circuit collects information about the battery and determines the working status of the battery; Step S2: the BMS main control circuit controls the pre-discharge switch and the charge switch to be turned on and the separation switch to be turned off according to the working state of the battery; Step S3: connecting the application system to the application system connector, the BMS main control circuit detecting the capacitor voltage of the system application, and controlling the discharge switch to be turned on when the capacitor voltage is greater than a preset voltage threshold; Step S4: the BMS main control circuit detects the discharge current of the battery, and controls the separation switch to be turned on when the discharge current is greater than a preset current threshold.

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