BMS awakening and pre-amplifying circuit

Abstract

The utility model discloses a BMS wake-up and pre-discharge circuit comprising a load pre-detection module, a pre-discharge module and a main loop protection module. The input end of the load pre-detection module is connected with a load end, and the output end of the load pre-detection module is connected with the MCU; the input end of the pre-amplification module is connected with the MCU, and the output end of the pre-amplification module is connected with the MOS main loop; according to the utility model, the load pre-detection module is connected with the load end, the access of the load can be detected under the condition that the load current is very small, the pre-detection signal is sent to the MCU, then the MCU sends the pre-discharge control signal to the pre-discharge module, the pre-discharge control signal can open the pre-discharge module, and then the MOS main loop is opened through the pre-discharge module, so that the BMS system is awakened; according to the utility model, after the MCU receives the pre-detection signal accessed by the low-current load, the BMS system is awakened by the pre-amplification module, and the BMS pre-detection circuit has the advantage of strong applicability.

Description

Technical Field

[0001] The utility model relates to the technical field of BMS, in particular to a BMS wake-up and pre-release circuit. Background Art

[0002] In the current lithium battery management system (BMS), after the lithium battery and the protection board are packaged into a battery pack according to the design requirements, the BMS system is in a long-term working state, but the battery pack may be in a long-term uncharged storage state in the application; the power consumption of the BMS system itself may consume the power of the lithium battery, that is, the full-speed operation of the BMS system will consume the power of the battery, causing the battery cell voltage to decrease, and eventually leading to BMS over-discharge. If the time is too long, it will cause lithium battery starvation and lithium deposition, resulting in safety problems; therefore, the BMS system needs to sleep to reduce power consumption. After the BMS system sleeps, it needs to wake up the BMS system to open the main circuit so that the BMS system can work normally. Currently, the load access method is mainly used to wake up the BMS system. For example, the Chinese utility model patent with the authorization announcement number CN214313307U discloses a BMS wake-up circuit, including a microcontroller unit MCU, a communication wake-up module, a load wake-up module and a charger wake-up module; the output end of the communication wake-up module, the output end of the load wake-up module and the output end of the charger wake-up module are all connected to the microcontroller unit MCU; the communication wake-up module includes a communication wake-up circuit and a communication wake-up undervoltage protection circuit connected to the communication wake-up circuit; the load wake-up module includes a load wake-up circuit and a load wake-up isolation circuit connected to the load wake-up circuit; the utility model can wake up the BMS system through the load wake-up module, and when the load is always connected, the BMS system can be woken up by communication and charger. However, in the application scenario of two-wheeled vehicles, there are currently some models whose load current is too small, and the AFE chip used to detect the load current cannot detect the too small load current, which causes the AFE chip to be unable to recognize the load connection, and the vehicle cannot be started or ridden normally. Utility Model Content

[0003] The purpose of the utility model is to provide a BMS wake-up and pre-discharge circuit. The utility model can wake up the BMS system by the pre-discharge module after the MCU receives the pre-detection signal of the small current load access, and has the advantage of strong applicability.

[0004] The technical solution of the utility model: a BMS wake-up and pre-release circuit, applied to a small current load, connected to a MOS main circuit and an MCU; comprising a load pre-detection module, a pre-release module and a main circuit protection module; the input end of the load pre-detection module is connected to the load end, and the output end of the load pre-detection module is connected to the MCU; the input end of the pre-release module is connected to the MCU, and the output end of the pre-release module is connected to the MOS main circuit; the pre-release module comprises a resistor R2, a resistor R5, a resistor R6, a resistor R7, a resistor R9, a resistor R10, a resistor R11, a voltage regulator diode DZ1 and an NMOS tube Q1; one end of the resistor R7 is connected to the MCU; the other end of the resistor R7 is connected to the voltage regulator diode DZ1 and the NMOS tube Q1. The cathode of the transistor DZ1, one end of the resistor R9 and the gate of the NMOS transistor Q1; the source of the NMOS transistor Q1 is connected to the other end of the resistor R9, the anode of the voltage stabilizing diode DZ1 and one end of the resistor R2, and the source of the NMOS transistor Q1 is connected to the MCU; the other end of the resistor R2 is connected to the main circuit protection module, and the other end of the resistor R2 is connected to the MOS main circuit; the drain of the NMOS transistor Q1 is connected to one end of the resistor R5 and one end of the resistor R6; the other end of the resistor R5 is connected to the other end of the resistor R6, one end of the resistor R10 and one end of the resistor R11; the other end of the resistor R10 is connected to the other end of the resistor R11, and the other end of the resistor R10 is connected to the main circuit protection module.

[0005] The above-mentioned BMS wake-up and pre-discharge circuit, the load pre-detection module includes a resistor R1, a resistor R4, a resistor R8, a capacitor C3 and a transistor Q2; one end of the resistor R4 is connected to the load end, and the other end of the resistor R4 is connected to one end of the resistor R8, one end of the capacitor C3 and the base of the transistor Q2; the other end of the resistor R8, the other end of the capacitor C3 and the emitter of the transistor Q2 are all grounded; the collector of the transistor Q2 is connected to the MCU, and the collector of the transistor Q2 is connected to one end of the resistor R1; the other end of the resistor R1 is connected to the voltage source.

[0006] The aforementioned BMS wake-up and pre-discharge circuit, the main circuit protection module includes capacitor C1, capacitor C2, bidirectional TVS tube TVS1, bidirectional TVS tube TVS2 and bidirectional TVS tube TVS3; one end of the capacitor C1 is connected to one end of the bidirectional TVS tube TVS1, one end of the bidirectional TVS tube TVS2 and one end of the bidirectional TVS tube TVS3, and one end of the capacitor C1 is connected to the pre-discharge module and the MOS main circuit; the other end of the capacitor C1 is connected to one end of the capacitor C2, the other end of the bidirectional TVS tube TVS1, the other end of the bidirectional TVS tube TVS2 and the other end of the bidirectional TVS tube TVS3, and the other end of the capacitor C1 is connected to the pre-discharge module; the other end of the capacitor C2 is connected to the MOS main circuit.

[0007] In the aforementioned BMS wake-up and pre-discharge circuit, the bidirectional TVS tube TVS1 is connected in parallel at both ends of the capacitor C1; the bidirectional TVS tube TVS2 is connected in parallel at both ends of the bidirectional TVS tube TVS1; and the bidirectional TVS tube TVS3 is connected in parallel at both ends of the bidirectional TVS tube TVS2.

[0008] Compared with the prior art, the utility model has the following beneficial effects:

[0009] 1. The load pre-detection module of the utility model is connected to the load end, and can detect the access of a small current load when the load current is very small; after detecting the access of the small current load, the load pre-detection module sends a pre-detection signal to the MCU by connecting to the MCU, and the MCU sends a pre-discharge control signal to the pre-discharge module. After the MCU receives the pre-detection signal after the access of the small current load, the pre-discharge control signal of the MCU can turn on the pre-discharge module, and then turn on the MOS main circuit through the pre-discharge module, thereby waking up the BMS system; the utility model can wake up the BMS system by the pre-discharge module after the MCU receives the pre-detection signal of the access of the small current load, and has the advantage of strong applicability; in addition, the main circuit protection module can protect the components in the circuit.

[0010] 2. The main circuit protection module of the utility model is connected in parallel with three bidirectional TVS tubes, which can effectively protect the components in the circuit from being damaged by transient voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a circuit diagram of the utility model.

[0012] The markings in the attached drawings are: 100 - load pre-check module, 200 - pre-release module, 300 - main circuit protection module. DETAILED DESCRIPTION

[0013] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0014] Example: BMS wake-up and pre-discharge circuit, the structure is as follows Figure 1As shown, it is applied to a small current load and connected to the MOS main circuit and MCU; it is characterized by: comprising a load pre-check module 100, a pre-amplifier module 200 and a main circuit protection module 300; the input end of the load pre-check module 100 is connected to the load end, and the output end of the load pre-check module 100 is connected to the MCU; the input end of the pre-amplifier module 200 is connected to the MCU, and the output end of the pre-amplifier module 200 is connected to the MOS main circuit. The pre-amplifier module 200 comprises a resistor R2, a resistor R5, a resistor R6, a resistor R7, a resistor R9, a resistor R10, a resistor R11, a voltage regulator diode DZ1 and an NMOS tube Q1; one end of the resistor R7 is connected to the MCU; the other end of the resistor R7 is connected to the cathode of the voltage regulator diode DZ1, one end of the resistor R9 and the gate of the NMOS tube Q1; the source of the NMOS tube Q1 is connected to the other end of the resistor R9, the anode of the voltage regulator diode DZ1 and one end of the resistor R2, and the source of the NMOS tube Q1 is connected to the cathode of the voltage regulator diode DZ1, one end of the resistor R9 and the gate of the NMOS tube Q1. The source is connected to the MCU, and the MCU provides a small current discharge; the other end of the resistor R2 is connected to the main circuit protection module 300, and the other end of the resistor R2 is connected to the MOS main circuit; the drain of the NMOS tube Q1 is connected to one end of the resistor R5 and one end of the resistor R6; the other end of the resistor R5 is connected to the other end of the resistor R6, one end of the resistor R10 and one end of the resistor R11; the other end of the resistor R10 is connected to the other end of the resistor R11, and the other end of the resistor R10 is connected to the main circuit protection module 300. The load pre-detection module 100 of the utility model is connected to the load end, and can detect the access of a small current load when the load current is very small; after detecting the access of the small current load, the load pre-detection module 100 sends a pre-detection signal to the MCU by connecting to the MCU, and the MCU sends a pre-discharge control signal to the pre-discharge module 200. After the MCU receives the pre-detection signal after the access of the small current load, the pre-discharge control signal of the MCU can turn on the pre-discharge module 200, and the pre-discharge module 200 can open the MOS main circuit after the MCU provides a small current discharge, thereby waking up the BMS system; in addition, the main circuit protection module 300 can protect the components in the circuit.

[0015] The load pre-detection module 100 includes a resistor R1, a resistor R4, a resistor R8, a capacitor C3 and a transistor Q2; one end of the resistor R4 is connected to a small current load, and the other end of the resistor R4 is connected to one end of the resistor R8, one end of the capacitor C3 and the base of the transistor Q2; the other end of the resistor R8, the other end of the capacitor C3 and the emitter of the transistor Q2 are all grounded; the collector of the transistor Q2 is connected to the MCU, and the collector of the transistor Q2 is connected to one end of the resistor R1; the other end of the resistor R1 is connected to a voltage source.

[0016] The main circuit protection module 300 includes capacitor C1, capacitor C2, bidirectional TVS tube TVS1, bidirectional TVS tube TVS2 and bidirectional TVS tube TVS3; one end of the capacitor C1 is connected to one end of the bidirectional TVS tube TVS1, one end of the bidirectional TVS tube TVS2 and one end of the bidirectional TVS tube TVS3, and one end of the capacitor C1 is connected to the pre-amplifier module 200 and the D_A end of the MOS main circuit; the other end of the capacitor C1 is connected to one end of the capacitor C2, the other end of the bidirectional TVS tube TVS1, the other end of the bidirectional TVS tube TVS2 and the other end of the bidirectional TVS tube TVS3, and the other end of the capacitor C1 is connected to the pre-amplifier module 200; the other end of the capacitor C2 is connected to the P-end of the MOS main circuit. The bidirectional TVS tube TVS1 is connected in parallel to both ends of the capacitor C1; the bidirectional TVS tube TVS2 is connected in parallel to both ends of the bidirectional TVS tube TVS1; the bidirectional TVS tube TVS3 is connected in parallel to both ends of the bidirectional TVS tube TVS2.

[0017] The utility model has been widely used in BMS systems and is compatible with most vehicle models on the market, which can reduce vehicle failure rates and debugging cycles during the development process.

[0018] Working principle: The load pre-detection module 100 of the utility model is connected to the load end, and can detect the connection of a small current load when the load current is very small; after detecting the connection of the small current load, the load pre-detection module 100 sends a pre-detection signal to the MCU by connecting to the MCU, and the MCU sends a pre-discharge control signal to the pre-discharge module 200. After the MCU receives the pre-detection signal after the small current load is connected, the pre-discharge control signal of the MCU can turn on the pre-discharge module 200, and the pre-discharge module 200 can open the MOS main circuit after the MCU provides a small current discharge, thereby waking up the BMS system; the utility model can wake up the BMS system by the pre-discharge module after the MCU receives the pre-detection signal of the small current load connection, and has the advantage of strong applicability; in addition, the main circuit protection module 300 can protect the components in the circuit.

[0019] The above embodiments only express the implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. In this embodiment, up, down, left, right, front, and back only represent their relative positions and do not represent their absolute positions. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A BMS wake-up and pre-discharge circuit, applied to low current loads, connected to the MOS main circuit and MCU; characterized in that: The invention comprises a load pre-detection module (100), a pre-amplification module (200) and a main circuit protection module (300); the input end of the load pre-detection module (100) is connected to the load end, and the output end of the load pre-detection module (100) is connected to the MCU; the input end of the pre-amplification module (200) is connected to the MCU, and the output end of the pre-amplification module (200) is connected to the MOS main circuit; the pre-amplification module (200) comprises a resistor R2, a resistor R5, a resistor R6, a resistor R7, a resistor R9, a resistor R10, a resistor R11, a voltage regulator diode DZ1 and an NMOS tube Q1; one end of the resistor R7 is connected to the MCU; the other end of the resistor R7 is connected to the cathode of the voltage regulator diode DZ1, the resistor R11, and the NMOS tube Q1; One end of the resistor R9 and the gate of the NMOS tube Q1; the source of the NMOS tube Q1 is connected to the other end of the resistor R9, the positive electrode of the voltage stabilizing diode DZ1 and one end of the resistor R2, and the source of the NMOS tube Q1 is connected to the MCU; the other end of the resistor R2 is connected to the main circuit protection module (300), and the other end of the resistor R2 is connected to the MOS main circuit; the drain of the NMOS tube Q1 is connected to one end of the resistor R5 and one end of the resistor R6; the other end of the resistor R5 is connected to the other end of the resistor R6, one end of the resistor R10 and one end of the resistor R11; the other end of the resistor R10 is connected to the other end of the resistor R11, and the other end of the resistor R10 is connected to the main circuit protection module (300).

2. The BMS wake-up and pre-discharge circuit according to claim 1, characterized in that: The load pre-detection module (100) comprises a resistor R1, a resistor R4, a resistor R8, a capacitor C3 and a transistor Q2; one end of the resistor R4 is connected to the load end, and the other end of the resistor R4 is connected to one end of the resistor R8, one end of the capacitor C3 and the base of the transistor Q2; the other end of the resistor R8, the other end of the capacitor C3 and the emitter of the transistor Q2 are all grounded; the collector of the transistor Q2 is connected to the MCU, and the collector of the transistor Q2 is connected to one end of the resistor R1; the other end of the resistor R1 is connected to a voltage source.

3. The BMS wake-up and pre-discharge circuit according to claim 1, characterized in that: The main circuit protection module (300) comprises a capacitor C1, a capacitor C2, a bidirectional TVS tube TVS1, a bidirectional TVS tube TVS2 and a bidirectional TVS tube TVS3; one end of the capacitor C1 is connected to one end of the bidirectional TVS tube TVS1, one end of the bidirectional TVS tube TVS2 and one end of the bidirectional TVS tube TVS3, and one end of the capacitor C1 is connected to a pre-amplifier module (200) and a MOS main circuit; the other end of the capacitor C1 is connected to one end of the capacitor C2, the other end of the bidirectional TVS tube TVS1, the other end of the bidirectional TVS tube TVS2 and the other end of the bidirectional TVS tube TVS3, and the other end of the capacitor C1 is connected to the pre-amplifier module (200); the other end of the capacitor C2 is connected to the MOS main circuit.

4. The BMS wake-up and pre-discharge circuit according to claim 3, characterized in that: The bidirectional TVS tube TVS1 is connected in parallel to both ends of the capacitor C1; the bidirectional TVS tube TVS2 is connected in parallel to both ends of the bidirectional TVS tube TVS1; and the bidirectional TVS tube TVS3 is connected in parallel to both ends of the bidirectional TVS tube TVS2.

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