BMS battery protection circuit capable of starting charging at 0V

Abstract

The utility model relates to the technical field of battery management systems, in particular to a battery management system (BMS) battery protection circuit capable of starting charging at 0V, which realizes the 0V charging starting function of a BMS by arranging an inner protection circuit and an outer protection circuit in front of a voltage-stabilizing power supply module. Wherein each of the inner protection circuit and the outer protection circuit comprises a resettable fuse, a transient suppression diode and an anti-reverse diode. When the battery is in a power-deficient state or in a 0V state and the BMS control IC is not started, the charger can directly supply power to the voltage stabilizing module through the external protection circuit to perform cold start on the BMS control IC, and the BMS control IC starts the charging MOS to charge the battery when detecting that a charging condition is met; a 0V charging starting function is realized, and no extra communication or voltage-stabilized power supply is needed. According to the utility model, the 0V starting function of the BMS and the voltage limiting protection, reverse prevention, current limiting and automatic recovery functions of the power supply branch of the voltage stabilizing module are integrated, the system reliability is greatly improved, the cost is low, and the practicability is good.

Description

Technical Field

[0001] The utility model relates to the technical field of battery management systems, in particular to a BMS battery protection circuit capable of starting charging at 0V. Background Art

[0002] In a battery management system (BMS), the charging and discharging of a battery pack are generally controlled by a charging control MOS transistor and a discharging control MOS transistor. The MOS transistors play a role in controlling overcharging, over-discharging, overcurrent during charging and discharging, etc., to ensure the efficient operation and safety of the battery. During the charging process, specifically, the charging control MOS transistor is controlled to turn on by an IC chip in the BMS, so that the charger can normally charge the battery pack. However, when the battery is severely discharged or completely out of power to 0V, the BMS cannot be started, and the charging control MOS transistor and the discharging control MOS transistor are in the off state. At this time, the charger cannot charge the battery, and it can only be solved by additionally connecting a regulated power supply and additional communication to the battery, resulting in inconvenience in use. Summary of the Utility Model

[0003] In view of this, the purpose of the utility model is to provide a BMS battery protection circuit capable of starting charging at 0V to solve the problem that the existing battery management system cannot charge the battery when the battery is severely discharged or completely out of power to 0V.

[0004] Based on the above purpose, the utility model provides a BMS battery protection circuit capable of starting charging at 0V, which includes a charger, a battery pack and a BMS, and also includes an internal protection circuit and an external protection circuit. Both the internal protection circuit and the external protection circuit include a self-resetting fuse, a diode, and a voltage-limiting branch composed of transient suppression diodes. One path of the self-resetting fuse is connected to a regulated power supply module through a diode, and the other path is connected to the regulated power supply module through the voltage-limiting branch. The regulated power supply module is used to supply power to the BMS. Two paths are led out from the charging interface of the charger. One path is connected to the charging control MOS transistor and then to the internal protection circuit, and the other path is connected to the external protection circuit. The positive electrode of the battery pack is connected between the charging control MOS transistor and the internal protection circuit, and the negative electrode is connected to the regulated power supply module. The internal protection circuit, the external protection circuit and the battery pack share the same negative electrode.

[0005] The present utility model also provides a BMS battery protection circuit capable of starting charging at 0V, which includes a charger, a battery pack, and a BMS, and also includes an internal protection circuit and an external protection circuit. Both the internal protection circuit and the external protection circuit include a self - restoring fuse, a diode, and a voltage - limiting branch composed of transient suppression diodes. One path of the self - restoring fuse is connected to the regulated power supply module through a diode, and the other path is connected to the regulated power supply module through the voltage - limiting branch. The regulated power supply module is used to supply power to the BMS. The charging interface of the charger has two output paths. One path is connected to the charging control MOS transistor and then connected to the internal protection circuit, and the other path is connected to the external protection circuit. The negative electrode of the battery pack is connected between the charging control MOS transistor and the internal protection circuit, and the positive electrode is connected to the regulated power supply module. The internal protection circuit, the external protection circuit, and the battery pack share the same positive electrode.

[0006] Preferably, the charging interface is the charging port of a split - port BMS or the common charge - discharge port of a same - port BMS.

[0007] Preferably, the battery pack is composed of single - string battery cells or multiple - string battery cells.

[0008] Preferably, the BMS includes a BMS control IC, and the BMS control IC is communicatively connected to the charging control MOS transistor for controlling the opening and closing of the charging control MOS transistor.

[0009] Preferably, the BMS control IC is communicatively connected to the charger for controlling the output voltage and current of the charger.

[0010] Preferably, the BMS further includes a BMS balancing module.

[0011] Advantages of the present utility model:

[0012] By pre - arranging an internal protection circuit and an external protection circuit in front of the regulated power supply module, the present utility model cleverly realizes the function of starting charging at 0V, without the need for additional communication or regulated power supply, with low cost, high reliability, and good practicability.

[0013] The internal protection circuit and the external protection circuit provided by the present utility model integrate functions of voltage - limiting protection, reverse - connection prevention, and automatic recovery, greatly increasing the system reliability and with low cost. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only those of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1Schematic diagram of the battery protection circuit (common negative electrode) of the BMS same-port solution according to the embodiment of the present invention;

[0016] Figure 2 Schematic diagram of the battery protection circuit (common negative electrode) of the BMS split-port solution according to the embodiment of the present invention;

[0017] Figure 3 Schematic diagram of the battery protection circuit (common positive electrode) of the BMS same-port solution according to the embodiment of the present invention;

[0018] Figure 4 Schematic diagram of the battery protection circuit (common positive electrode) of the BMS split-port solution according to the embodiment of the present invention. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments.

[0020] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meanings understood by those with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0021] Description of the utility model:

[0022] I. System composition and characteristics:

[0023] System composition: charger, battery pack composed of single-series or multi-series battery cells, BMS;

[0024] Scope of application: The BMS is a common negative electrode or common positive electrode circuit. The BMS is a common-port same-port charge and discharge circuit or a same-port charge and discharge circuit.

[0025] II. Solving pain points: When the battery is severely discharged or completely out of power to 0V, the BMS system cannot be started, and the charging port MOS tube and the discharging port MOS tube are in the off state. At this time, when the charger charges the battery, the charging cannot be started.

[0026] III: Device Description and Operating Principle of This System

[0027] Device Description: Explanation of Component Symbols: TVS: Transient Voltage Suppressor Diode, PTC: Polymeric Positive Temperature Coefficient Resettable Fuse, D: Diode

[0028] IV: Description of the Composition and Variation Types of the BMS System of This Utility Model

[0029] 4.1: Dual-channel Protection Circuit in Front of the Voltage Regulation Module; (Divided into External Protection Circuit and Internal Protection Circuit. The external protection circuit consists of PTC-1, TVS1, and D1; the internal protection circuit consists of PTC-2, TVS2, and D2)

[0030] 4.2: Voltage Regulation Power Supply Module; (Supplies power to the BMS Control IC)

[0031] 4.3: BMS Control IC Module; (Includes Peripheral Circuits and Sensors);

[0032] 4.4: Charge / Discharge Control MOS

[0033] 4.5: BMS Equalization Circuit / Module; (Not Necessary);

[0034] V: Description of the BMS Operating Mode

[0035] The charger is connected to the battery BMS.

[0036] If the battery or battery pack is normal, the BMS works normally. And if it is determined that the battery is chargeable, the BMS control IC module sends a signal to turn on the charge control MOSFET to charge the battery. The charger and the BMS can be connected with communication or without communication. When connected with communication, the charger provides the voltage and current required by the BMS control IC to start charging.

[0037] If the BMS is not started, it may be that the battery is severely discharged or in a 0V state, or the battery may be damaged. Then the charging voltage passes through the external protection circuit of the dual-channel protection circuit in front of the voltage regulation module of this utility model, that is, the overvoltage protection of the polymeric positive temperature coefficient resettable fuse PTC-1 and TVS1, and then through the reverse protection of D1 to start the voltage regulation power supply module to supply power to the BMS control IC, cold-starting the BMS system. At this time, the BMS analyzes the battery state. When the battery / battery pack is in an allowable charging state, it turns on the charge control MOS to start charging. If the battery is damaged or the input voltage at the charging port is overvoltage, it does not charge.

[0038] After turning on the charge control MOSFET, the dual-channel protection circuit in front of the voltage regulation module supplies power to the voltage regulation power supply module together.

[0039] After turning off the charging control MOS transistor, if the battery voltage is within the startup voltage range of the regulated power supply module, the internal protection circuit composed of PTC-2, TVS2, and D2 limits the voltage and provides reverse protection, and then supplies power to the regulated power supply module.

[0040] VI. Features and advantages of the present system:

[0041] 1. After the charger is connected and powered on, even if the battery / battery pack voltage is severely depleted, or even 0V, as long as there is a voltage higher than the minimum startup voltage Vmin at the charging port, the BMS can be cold-started to charge the battery / battery pack. And the communication function is not necessary.

[0042] 2. When there is an abnormal high voltage at the charging port, TVS1 is triggered to turn on and conduct instantaneously, clamping the voltage of the input regulated power supply within a reasonable range. Under extreme conditions, PTC-1 can be triggered to enter a high-resistance state to prevent the high voltage from entering the regulated power supply module, and it can return to the normal low-resistance state after the high voltage disappears.

[0043] 3. When there is an abnormal high voltage at the battery port, TVS2 is triggered to turn on and conduct instantaneously, clamping the voltage of the input regulated power supply within a reasonable range. Under extreme conditions, PTC-2 can be triggered to enter a high-resistance state to prevent the high voltage from entering the regulated power supply module, and it can return to the normal low-resistance state after the high voltage disappears.

[0044] 4. The dual-channel protection circuit in front of the voltage regulation module integrates functions such as overvoltage protection, reverse protection, and current-limiting automatic recovery, greatly increasing the system reliability and with a relatively low cost.

[0045] 5. The dual-channel protection circuit in front of the present voltage regulation module cleverly realizes the 0V startup charging function, integrates functions such as overvoltage protection, reverse protection, current-limiting and automatic recovery of the power supply branch of the voltage regulation module, and does not require additional communication or regulated power supply, with a relatively low cost, high reliability, and good practicability. This solution has good versatility and can be applied to the BMS battery protection circuit with a common positive or common negative pole. And the communication function between the charger and the BMS is not necessary.

[0046] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features between the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

[0047] Any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A BMS battery protection circuit capable of 0V start charging, comprising a charger, a battery pack and a BMS, characterized in that: It also includes an internal protection circuit and an external protection circuit, both of which include a resettable fuse, a diode, and a voltage-limiting branch composed of a transient suppression diode. One path of the resettable fuse is connected to a voltage-stabilized power supply module through a diode, and the other path is connected to the voltage-stabilized power supply module through the voltage-limiting branch. The voltage-stabilized power supply module is used to power the BMS. The charging interface of the charger has two connections, one of which is connected to the charging control MOS tube and then connected to the internal protection circuit, and the other is connected to the external protection circuit. The positive pole of the battery pack is connected between the charging control MOS tube and the internal protection circuit, and the negative pole is connected to the voltage-stabilized power supply module. The internal protection circuit, the external protection circuit and the battery pack share a negative pole.

2. A BMS battery protection circuit capable of 0V start charging, comprising a charger, a battery pack and a BMS, characterized in that: It also includes an internal protection circuit and an external protection circuit, both of which include a resettable fuse, a diode, and a voltage-limiting branch composed of a transient suppression diode. One path of the resettable fuse is connected to a voltage-stabilized power supply module through a diode, and the other path is connected to the voltage-stabilized power supply module through the voltage-limiting branch. The voltage-stabilized power supply module is used to power the BMS. The charging interface of the charger has two connections, one of which is connected to the charging control MOS tube and then connected to the internal protection circuit, and the other is connected to the external protection circuit. The negative pole of the battery pack is connected between the charging control MOS tube and the internal protection circuit, and the positive pole is connected to the voltage-stabilized power supply module. The internal protection circuit, the external protection circuit and the battery pack share a common positive pole.

3. The BMS battery protection circuit capable of 0V start charging according to claim 1 or 2, characterized in that: The charging interface is a charging port of a separate-port BMS or a common charging and discharging port of a single-port BMS.

4. The BMS battery protection circuit capable of 0V start charging according to claim 1 or 2, characterized in that: The battery pack is composed of a single string of battery cells or multiple strings of battery cells.

5. The BMS battery protection circuit capable of 0V start charging according to claim 1 or 2, characterized in that: The BMS includes a BMS control IC, and the BMS control IC is communicatively connected with the charging control MOS tube and is used to control the on and off of the charging control MOS tube.

6. The BMS battery protection circuit capable of 0V start charging according to claim 5, characterized in that: The BMS control IC is in communication connection with the charger and is used to control the output voltage and current of the charger.

7. The BMS battery protection circuit capable of 0V start charging according to claim 5, characterized in that: The BMS also includes a BMS balancing module.

Images