CN-224217517-U - High-voltage acquisition circuit of battery management system

Abstract

The utility model relates to the technical field of BMS (battery management system), in particular to a high-voltage acquisition circuit of a battery management system. The battery voltage sampling circuit is characterized by comprising a voltage dividing circuit, a high-voltage sampling control circuit, a linear optical coupler and a differential proportion operation circuit, a main control unit and a control unit, wherein the voltage dividing circuit and the high-voltage sampling control circuit are used for acquiring battery voltage and forming a sampling signal HV_V, the linear optical coupler and the differential proportion operation circuit are connected with the voltage dividing circuit and the high-voltage sampling control circuit in an adaptive mode and used for receiving the sampling signal HV_V and forming a signal HV_V_AD, the main control unit is connected with the voltage dividing circuit and the high-voltage sampling control circuit in an adaptive mode, the main control unit sends control signals to the voltage dividing circuit and the high-voltage sampling control circuit and controls the high-voltage sampling control circuit to generate the sampling signal HV_V, and the main control unit receives the signal HV_V_AD. The circuit has low cost and good common mode immunity.

Inventors

• YANG HAIJUN
• SUN PENG
• JIANG YUEMING
• LI RUI

Assignees

• 江苏纵浪焕能技术有限公司

Dates

Publication Date

20260508

Application Date

20250526

Claims (6)

1. 1. A battery management system high voltage acquisition circuit, comprising: The voltage dividing circuit and the high-voltage sampling control circuit are used for collecting the battery voltage and forming a sampling signal HV_V; The linear optocoupler and the differential proportion operation circuit are connected with the voltage dividing circuit and the high-voltage sampling control circuit in an adaptive manner and are used for receiving a sampling signal HV_V and forming a signal HV_V_AD; The main control unit is connected with the voltage dividing circuit, the high-voltage sampling control circuit, the linear optical coupler and the differential proportion operation circuit in an adaptive mode, and is used for sending control signals to the voltage dividing circuit and the high-voltage sampling control circuit to control the high-voltage sampling control circuit to generate sampling signals HV_V, and the main control unit is used for receiving the signals HV_V_AD.
2. 2. The battery management system high voltage acquisition circuit as claimed in claim 1, wherein the voltage dividing circuit and the high voltage sampling control circuit comprise an optocoupler isolator U1, a controlled end of the optocoupler isolator U1 is used for being connected with the battery to form the sampling signal HV_V, and a control end of the optocoupler isolator U1 is connected with the main control unit to receive the control signal and control a controlled end of the optocoupler isolator U1 to generate the sampling signal HV_V.
3. 3. The battery management system high voltage acquisition circuit as claimed in claim 2, wherein the controlled end of the photo-coupler isolator U1 comprises a photosensitive switch tube, one end of the photosensitive switch tube is connected with 2 resistors in series and then used for receiving a high voltage signal HV, one end of a resistor R9 at the other end of the photosensitive switch tube is connected, the other end of the resistor R9 is grounded through a resistor R12, the control end of the photo-coupler isolator U1 comprises a light emitting diode used for driving the photosensitive switch tube to conduct, the anode of the light emitting diode is connected with a resistor in series and then connected with a power supply VCC, the cathode of the light emitting diode is connected with the collector of the triode Q, the base of the triode Q is connected with another resistor in series and then used for receiving the control signal, the base of the triode Q is connected with the ground after the base of the triode Q is connected with the other resistor in series, the triode Q is conducted after the control is sent and controlled, the light emitting diode is conducted to generate light, and the photosensitive switch tube is conducted to form the sampling signal HV_V.
4. 4. A battery management system high voltage acquisition circuit as claimed in claim 3, wherein the plurality of photosensitive switching tubes are provided, one end of each photosensitive switching tube is connected with 2 resistors in series and then used for receiving different high voltage signals HV, the other end of each photosensitive switching tube is connected with one end of a resistor R9 which is not connected with the resistor R12, each photosensitive switching tube corresponds to a light emitting diode, each light emitting diode corresponds to a triode Q, and the main control unit sends control signals to the corresponding triode Q so as to generate corresponding sampling signals hv_v to form multi-channel sampling.
5. 5. The battery management system high voltage acquisition circuit of claim 1, wherein the linear optocoupler and differential ratio operation circuit comprises a linear optocoupler U2, an input side Vin pin of the linear optocoupler U2 is used for receiving the sampling signal hv_v, an input side Vin pin of the linear optocoupler U2 is respectively connected with one ends of a capacitor C6 and a capacitor C7, the other ends of the capacitor C6 and the capacitor C7 are grounded, an input side SHIN pin of the linear optocoupler U2 is grounded, and an output side VOUT1 pin and VOUT2 of the linear optocoupler U2 form the signal hv_v_ad after passing through the differential circuit.
6. 6. The battery management system high voltage acquisition circuit according to claim 5, wherein the differential circuit comprises an operational amplifier U3B and an operational amplifier U3A, the output side VOUT1 pin of the linear optocoupler U2 is connected with one end of a resistor R18, the other end of the resistor R18 is connected with the non-inverting input end of the operational amplifier U3B, one end of a resistor R20 and one end of a capacitor C9, and the other end of the resistor R20 and the other end of the capacitor C9 are grounded; the output side VOUT2 pin of the linear optocoupler U2 is connected with one end of a resistor R15 and one end of a resistor R16, the other end of the resistor R15 is connected with an inverting input end of an operational amplifier U3A, the other end of the resistor R16 is connected with an inverting input end of an operational amplifier U3B, the output end of the operational amplifier U3B is respectively connected with one end of a capacitor C2, one end of a resistor R14 and one end of a resistor R17, the other end of the capacitor C2 and the other end of the resistor R14 are both connected with an inverting input end of the operational amplifier U3B to form negative feedback, the other end of the resistor R17 is respectively connected with an in-phase input end of the operational amplifier U3A, one end of a resistor R19 and one end of a capacitor C8, the other end of the resistor R19 and the other end of the capacitor C8 are both grounded, the output end of the operational amplifier U3A is respectively connected with one end of a capacitor C1 and one end of a resistor R13, the other end of the capacitor C1 and the other end of the resistor R13 are both connected with the inverting input end of the operational amplifier U3A to form negative feedback signal AD, and the output end of the negative feedback signal HV_A is formed.

Description

High-voltage acquisition circuit of battery management system Technical Field The utility model relates to the technical field of BMS (battery management system), in particular to a high-voltage acquisition circuit of a battery management system. Background BMS systems, i.e., battery management systems (Battery MANAGEMENT SYSTEM), are an indispensable core component in electric vehicles and energy storage systems. The system plays a role of a central of the battery pack, is responsible for comprehensively monitoring, managing and maintaining the battery module, ensures safe and efficient operation of the battery, and prolongs the service life of the battery. The system has higher acquisition precision, signal-to-noise ratio and higher stability, and can realize the accurate and stable safety management of the high-voltage acquisition circuit on the SOC, SOH and power battery estimated by the battery management system. At present, a traditional battery management system high-voltage acquisition circuit comprises a voltage division module, a differential acquisition module, an ADC module, a separation module and a communication module. The high-voltage signal is divided by the voltage dividing module, the sampling signal is formed by differential measurement and differential signal adjustment of the differential acquisition module, and then acquired by an integrated chip ADC of the ADC module, and the sampling signal is transmitted to the singlechip through the separation module and the communication module. The acquisition circuit is acquired by an integrated chip, the integrated chip is high in price, the cost is high, and the common mode immunity of the integrated chip is poor. Disclosure of utility model The utility model aims to solve the technical problem of providing a high-voltage acquisition circuit of a battery management system, which has low cost and good common mode immunity. In order to solve the problems, the following technical scheme is provided: the high-voltage acquisition circuit of the battery management system is characterized by comprising the following components: The voltage dividing circuit and the high-voltage sampling control circuit are used for collecting the battery voltage and forming a sampling signal HV_V; The linear optocoupler and the differential proportion operation circuit are connected with the voltage dividing circuit and the high-voltage sampling control circuit in an adaptive manner and are used for receiving a sampling signal HV_V and forming a signal HV_V_AD; The main control unit is connected with the voltage dividing circuit, the high-voltage sampling control circuit, the linear optical coupler and the differential proportion operation circuit in an adaptive mode, and is used for sending control signals to the voltage dividing circuit and the high-voltage sampling control circuit to control the high-voltage sampling control circuit to generate sampling signals HV_V, and the main control unit is used for receiving the signals HV_V_AD. The voltage dividing circuit and the high-voltage sampling control circuit comprise an optical coupler isolator U1, wherein a controlled end of the optical coupler isolator U1 is used for being connected with the battery and used for forming the sampling signal HV_V, and a control end of the optical coupler isolator U1 is connected with the main control unit and used for receiving the control signal and controlling a controlled end of the optical coupler isolator U1 to generate the sampling signal HV_V. The control end of the opto-coupler isolator U1 comprises a photosensitive switch tube, one end of the photosensitive switch tube is connected with 2 resistors in series and then is used for receiving a high-voltage signal HV, one end of a resistor R9 at the other end of the photosensitive switch tube is connected with the other end of the photosensitive switch tube, the other end of the resistor R9 is grounded through a resistor R12, the control end of the opto-coupler isolator U1 comprises a light emitting diode used for driving the photosensitive switch tube to conduct, the anode of the light emitting diode is connected with a resistor in series and then is connected with a power supply VCC, the cathode of the light emitting diode is connected with the collector of a triode Q, the base of the triode Q is connected with a resistor in series and then is used for receiving a control signal, the base of the triode Q is connected with the other resistor in series and then is grounded, the emitter of the triode Q is grounded, after control is sent and control, the triode Q is conducted, the light emitting diode is conducted and the photosensitive switch tube is conducted to form a light sampling signal HV_V. The photosensitive switch tubes are multiple, one end of each photosensitive switch tube is connected in series with 2 resistors and then used for receiving different high-voltage signals HV, the other end of each photosensitive swit