Sampling circuit for current detection of shunt and energy storage battery management system

Abstract

The utility model relates to a sampling circuit for current detection of a shunt and an energy storage battery management system. The sampling circuit comprises a signal amplification module which is used for collecting electric signals at the two ends of the shunt and enhancing the intensity and quality of current signals; the analog-to-digital conversion module is used for converting the electric signal output by the signal amplification module into a digital signal; the digital signal isolation module is used for converting the digital signal output by the analog-to-digital conversion module into an isolated digital signal; and the reference voltage module is connected with the signal amplification module, and the reference voltage module is used for providing reference voltage for the signal amplification module. According to the sampling circuit for current detection of the shunt, acquired voltage signals are stably transmitted to the BMS main processing chip for current processing through the amplifier, the data acquisition-digital analog converter, the digital isolator and the like, current detection is accurate, and anti-interference performance is high.

Description

Technical Field

[0001] The utility model relates to the technical field of current detection, in particular to a sampling circuit for shunt current detection and an energy storage battery management system. Background Art

[0002] The power battery system or energy storage battery system will be affected by changes in current and voltage during operation. Testers can use equipment such as oscilloscopes to monitor and record the current and voltage of the battery system in real time. By analyzing the fluctuations in current and voltage, they can determine whether the battery system has safety hazards such as overcharging, over-discharging or short circuit.

[0003] The current value is an important parameter of energy storage batteries or power batteries. It is an important input parameter of the battery management system. The current value is used in the estimation algorithm of many parameters of the energy storage battery. The current value is usually obtained through current sensors. Its sampling accuracy directly affects the accuracy of the estimation of various parameters of the energy storage battery in the BMS.

[0004] At present, the accuracy of current sampling values ​​is mainly improved by selecting a higher-precision current sensor. However, the improvement in hardware accuracy is also limited, and a higher-precision current sensor will also increase the cost of the system. Utility Model Content

[0005] Based on this, it is necessary to provide a sampling circuit for shunt current detection and an energy storage battery management system that can obtain high-precision current values ​​at low cost.

[0006] In a first aspect, the present application provides a sampling circuit for shunt current detection. The sampling circuit is used to collect electrical signals at both ends of the shunt and convert the electrical signals into digital signals; the sampling circuit includes:

[0007] A signal amplification module, the signal amplification module is used to collect the electrical signals at both ends of the splitter and enhance the strength and quality of the electrical signals;

[0008] An analog-to-digital conversion module, the digital-to-analog conversion module is connected to the signal amplification module, and the analog-to-digital conversion module is used to convert the analog signal output by the signal amplification module into a digital signal;

[0009] A digital signal isolation module, the digital signal isolation module is connected to the digital-to-analog conversion module, and the digital signal isolation module is used to convert the digital signal output by the analog-to-digital conversion module into an isolated digital signal;

[0010] A reference voltage module is connected to the signal amplification module and is used to provide a reference voltage to the signal amplification module.

[0011] In one embodiment, the signal amplification module includes:

[0012] An amplifier chip U3, wherein the enable input terminal of the amplifier chip U3 is connected to a pull-up resistor R27, the inverting input terminal of the amplifier chip U3 is connected to one end of the shunt, the positive input terminal of the amplifier chip U3 is connected to the other end of the shunt, a first filter module is connected between the positive input terminal of the amplifier chip U3 and the shunt, and a first filter module is connected between the reverse input terminal of the amplifier chip U3 and the shunt;

[0013] A voltage regulator diode D9 is also connected between the shunt and the first filter module, the positive electrode of the voltage regulator diode D9 is grounded, and the negative electrode of the voltage regulator diode D9 is connected to one end of the shunt. A voltage regulator diode D8 is also connected between the shunt and the first filter module, the positive electrode of the voltage regulator diode D8 is grounded, and the negative electrode of the voltage regulator diode D8 is connected to the shunt;

[0014] The common ground terminal of the amplifier chip U3 is grounded, the internal working voltage terminal of the amplifier chip U3 is grounded through the second filtering module, the output terminal of the amplifier chip U3 is connected to the resistor R1, the feedback input terminal of the amplifier chip U3 is connected to the output terminal of the amplifier chip U3 through the resistor R31, the reference input terminal of the amplifier chip is connected to the reference voltage through the resistor R33, the connection between the resistor R31 and the feedback input terminal of the amplifier chip U3 is connected to the resistor R32, and the other end of the resistor R32 is connected to the reference voltage.

[0015] In one embodiment, the first filtering module includes:

[0016] The first sub-filter module includes a capacitor C17 connected to the reverse input terminal of the amplifier chip U3, wherein the connection between the capacitor C17 and the reverse input terminal of the amplifier chip U3 is also connected to one end of a resistor R28, and the other end of the resistor R28 is connected to the shunt;

[0017] The second sub-filter module includes a capacitor C25 connected to the positive input terminal of the amplifier chip U3, wherein the connection between the capacitor C25 and the positive input terminal of the amplifier chip U3 is also connected to one end of a resistor R30, and the other end of the resistor R30 is connected to the shunt;

[0018] A capacitor C24 is also connected between the positive input terminal and the negative input terminal of the amplifier chip U3.

[0019] In one embodiment, the second filtering module includes:

[0020] Capacitor C18, one end of the capacitor C18 is connected to the internal working voltage terminal of the amplifier chip U3, the other end of the capacitor C18 is grounded, the connection between the capacitor C18 and the internal working voltage terminal of the amplifier chip U3 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the 3.3V input terminal, the connection between the resistor R5 and the 3.3V input terminal is connected to one end of the capacitor C26, and the other end of the capacitor C26 is grounded.

[0021] In one embodiment, the analog-to-digital conversion module includes:

[0022] An analog-to-digital converter chip U2, wherein the IN+ pin of the analog-to-digital converter chip U2 is connected to the output end of the amplifier chip U3 through a third filtering module, the VCC end of the analog-to-digital converter chip U2 is connected to a 3.3V input end, and a fourth filtering module for filtering out clutter is further connected at the connection between the VCC end and the 3.3V input end of the analog-to-digital converter chip U2, the IN- end of the analog-to-digital converter chip U2 is grounded through a resistor R14, the REF- end of the analog-to-digital converter chip U2 is grounded, and the GND end of the analog-to-digital converter chip U2 is grounded;

[0023] The CS+ end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SDI end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the CS+ end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SCK end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SDO end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the COMP end of the analog-to-digital converter chip U2 is grounded through capacitor C8, and the REFOUT end of the analog-to-digital converter chip U2 is grounded through capacitor C23.

[0024] In one embodiment, the third filtering module is used to filter the analog signal output from the output end of the amplifier chip U3, and the third filtering module includes:

[0025] The third filtering module includes a resistor R6 and a capacitor C7 connected in parallel, one end of the resistor R6 is grounded, and the other end of the resistor R6 is connected to the IN+ pin of the analog-to-digital converter chip U2, one end of the capacitor C7 is grounded, and the other end of the capacitor C7 is connected to the IN+ pin of the analog-to-digital converter chip U2.

[0026] In one embodiment, the fourth filtering module is used to filter the current of the 3.3V input terminal, and the fourth filtering module includes:

[0027] The fourth filtering module includes a capacitor C1 and a capacitor C2 connected in parallel, one end of the capacitor C1 is connected to the connection between the 3.3V input terminal and the VCC terminal of the amplifier chip U3, and the other end of the capacitor C1 is grounded.

[0028] In one embodiment, the digital signal isolation module includes:

[0029] A digital signal isolation chip U4, wherein the OUTA end of the digital signal isolation chip U4 is connected to the SDI end of the analog-to-digital converter chip U2, the OUTB end of the digital signal isolation chip U4 is connected to the SCK end of the analog-to-digital converter chip U2, the OUTC end of the digital signal isolation chip U4 is connected to the CS+ end of the analog-to-digital converter chip U2, the OUTD end of the digital signal isolation chip U4 is connected to the SDO end of the analog-to-digital converter chip U2, the INA, INB, INC and IND ends of the digital signal isolation chip U4 are connected to the 3.3V input end through an RC filtering module, and the VDD end of the digital signal isolation chip U4 is connected to the 3.3V input end through a capacitor filtering module.

[0030] In one embodiment, the reference voltage module includes:

[0031] The reference voltage chip U1 has an OUT pin connected to the feedback input terminal and the reference input terminal of the amplifier chip U3, and the VDD terminal and SHDN terminal of the reference voltage chip U1 are connected to the 3.3V input terminal through a capacitor filter module.

[0032] In a second aspect, the present application further provides an energy storage battery management system, comprising a sampling circuit for shunt current detection provided in the first aspect.

[0033] In the above sampling circuit for shunt current detection, the collected voltage signal is stably transmitted to the BMS main processing chip for current processing through amplifiers, data acquisition-digital-to-analog converters, and digital isolators, etc., and the current detection is accurate and has strong anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are 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 creative work.

[0035] FIG1 is a specific circuit diagram of a signal amplification module in a circuit monitoring circuit;

[0036] FIG2 is a specific circuit diagram of the first filtering module in the signal amplification module in FIG1 ;

[0037] FIG3 is a specific circuit diagram of the second filtering module in the signal amplification module in FIG1 ;

[0038] FIG4 is a specific circuit diagram of an analog-to-digital conversion module in a circuit monitoring circuit;

[0039] FIG5 is a specific circuit diagram of the third filtering module in the analog-to-digital conversion module in FIG4 ;

[0040] FIG6 is a specific circuit diagram of the fourth filtering module in the analog-to-digital conversion module in FIG4 ;

[0041] FIG7 is a specific circuit diagram of a digital signal isolation module in a circuit monitoring circuit;

[0042] FIG8 is a specific circuit diagram of a reference voltage module in a circuit monitoring circuit.

[0043] 1-signal amplification circuit, 10-shunt, 11-first filtering module, 12-second filtering module, 2-analog-to-digital conversion module, 21-third filtering module, 22-fourth filtering module, 3-digital signal isolation module, 4-reference voltage module. DETAILED DESCRIPTION

[0044] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0046] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0047] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0048] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0049] As shown in FIG. 1 , FIG. 2 , FIG. 3 and FIG. 4 , a sampling circuit for shunt current detection is used to collect electrical signals at both ends of the shunt and convert the electrical signals into digital signals. The electrical signals include voltage signals at both ends of the shunt. By accurately measuring the precise voltage at both ends of the shunt, the current in the circuit is accurately calculated according to Ohm's law. The shunt can use a shunt resistor, etc. The resistance value of the shunt resistor can be selected from a chip resistor ranging from a few micro-ohms to several hundred milliohms according to actual needs; including:

[0050] A signal amplification module, the signal amplification module is used to collect the electrical signals at both ends of the splitter and enhance the strength and quality of the electrical signals;

[0051] An analog-to-digital conversion module, the digital-to-analog conversion module is connected to the signal amplification module, and the analog-to-digital conversion module is used to convert the analog signal output by the signal amplification module into a digital signal;

[0052] A digital signal isolation module, the digital signal isolation module is connected to the digital-to-analog conversion module, and the digital signal isolation module is used to convert the digital signal output by the analog-to-digital conversion module into an isolated digital signal;

[0053] A reference voltage module is connected to the signal amplification module and is used to provide a reference voltage to the signal amplification module.

[0054] The utility model transmits the collected voltage signal stably to the BMS main processing chip for current processing through an amplifier, a data acquisition-digital-to-analog converter and a digital isolator, etc., and the current detection is accurate and has strong anti-interference performance.

[0055] As shown in FIG1 , the signal amplification module includes: an amplifier chip U3, an enable input terminal of the amplifier chip U3 is connected to a pull-up resistor R27, an inverting input terminal of the amplifier chip U3 is connected to one end of the shunt, a positive input terminal of the amplifier chip U3 is connected to the other end of the shunt and the other end is connected to the negative electrode of the battery, a first filter module is connected between the positive input terminal of the amplifier chip U3 and the shunt, and a first filter module is connected between the reverse input terminal of the amplifier chip U3 and the shunt;

[0056] A voltage regulator diode D9 is also connected between the shunt and the first filter module, the positive electrode of the voltage regulator diode D9 is grounded, and the negative electrode of the voltage regulator diode D9 is connected to the shunt. A voltage regulator diode D8 is also connected between the shunt and the first filter module, the positive electrode of the voltage regulator diode D8 is grounded, and the negative electrode of the voltage regulator diode D8 is connected to the shunt.

[0057] The common ground terminal of the amplifier chip U3 is grounded, the internal working voltage terminal of the amplifier chip U3 is grounded through the second filtering module, the output terminal of the amplifier chip U3 is connected to the resistor R1, the feedback input terminal of the amplifier chip U3 is connected to the output terminal of the amplifier chip U3 through the resistor R31, the reference input terminal of the amplifier chip is connected to the 1.8V reference input through the resistor R33, the connection between the resistor R31 and the feedback input terminal of the amplifier chip U3 is connected to the resistor R32, and the other end of the resistor R32 is connected to the 1.8V reference input, that is, connected to the reference voltage terminal.

[0058] Exemplarily, the amplifier chip U3 can adopt an operational amplifier with high precision, low noise level and high common-mode rejection ratio; it can provide clearer and more reliable signals during signal processing, effectively reduce the impact of common-mode noise or interference, and improve the reliability and stability of the system.

[0059] As shown in FIG. 2 , the first filtering module and the second filtering module respectively filter out clutter from the input signals at both ends of the splitter, and the first filtering module includes a first sub-filtering module and a second sub-filtering module.

[0060] The first sub-filter module includes a capacitor C17 connected to the reverse input terminal of the amplifier chip U3, the connection between the capacitor C17 and the reverse input terminal of the amplifier chip U3 is also connected to one end of a resistor R28, and the other end of the resistor R28 is connected to the shunt;

[0061] The second sub-filter module includes a capacitor C25 connected to the positive input terminal of the amplifier chip U3, wherein the connection between the capacitor C25 and the positive input terminal of the amplifier chip U3 is also connected to one end of a resistor R30, and the other end of the resistor R30 is connected to the shunt;

[0062] A capacitor C24 is also connected between the positive input terminal and the negative input terminal of the amplifier chip U3.

[0063] As shown in FIG4 , the analog-to-digital conversion module is used to convert the analog signal output by the signal amplification module into a digital signal. The analog-to-digital conversion module includes:

[0064] An analog-to-digital converter chip U2, wherein the IN+ pin of the analog-to-digital converter chip U2 is connected to the output end of the amplifier chip U3 through a third filtering module, the VCC end of the analog-to-digital converter chip U2 is connected to a 3.3V input end, and a fourth filtering module for filtering out clutter is further connected at the connection between the VCC end and the 3.3V input end of the analog-to-digital converter chip U2, the IN- end of the analog-to-digital converter chip U2 is grounded through a resistor R14, the REF- end of the analog-to-digital converter chip U2 is grounded, and the GND end of the analog-to-digital converter chip U2 is grounded;

[0065] The CS+ end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SDI end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the CS+ end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SCK end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SDO end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the COMP end of the analog-to-digital converter chip U2 is grounded through capacitor C8, and the REFOUT end of the analog-to-digital converter chip U2 is grounded through capacitor C23.

[0066] The analog-to-digital converter chip U2 can use a chip with 4 independent current detection channels and 4 voltage detection channels, which can accurately measure parameters such as input current, input voltage, output current, output voltage and power of each channel, and provide multiple protection functions to ensure the safety and stability of the system.

[0067] As shown in FIG5 , the third filtering module is used to filter the analog signal outputted from the output end of the amplifier chip U3, and the third filtering module includes:

[0068] The third filtering module includes a resistor R6 and a capacitor C7 connected in parallel, one end of the resistor R6 is grounded, and the other end of the resistor R6 is connected to the IN+ pin of the analog-to-digital converter chip U2, one end of the capacitor C7 is grounded, and the other end of the capacitor C7 is connected to the IN+ pin of the analog-to-digital converter chip U2.

[0069] As shown in FIG6 , the fourth filtering module is used to filter the current of the 3.3V input terminal, and the fourth filtering module includes:

[0070] The fourth filtering module includes a capacitor C1 and a capacitor C2 connected in parallel, one end of the capacitor C1 is connected to the connection between the 3.3V input terminal and the VCC terminal of the amplifier chip U3, and the other end of the capacitor C1 is grounded.

[0071] As shown in Figure 7, the digital signal isolation module includes: a digital signal isolation chip U4, the OUTA end of the digital signal isolation chip U4 is connected to the SDI end of the analog-to-digital converter chip U2, the OUTB end of the digital signal isolation chip U4 is connected to the SCK end of the analog-to-digital converter chip U2, the OUTC end of the digital signal isolation chip U4 is connected to the CS+ end of the analog-to-digital converter chip U2, the OUTD end of the digital signal isolation chip U4 is connected to the SDO end of the analog-to-digital converter chip U2, the INA, INB, INC and IND ends of the digital signal isolation chip U4 are connected to the 3.3V input end through the RC filtering module, and the VDD end of the digital signal isolation chip U4 is connected to the 3.3V input end through the capacitor filtering module.

[0072] The digital signal isolation chip U4 can use the isolated power supply DC-DC converter four-channel digital isolator SOP-16; the digital isolator is a device used to isolate digital signals, and its principle and function are very important. The digital isolator mainly cuts off the electrical connection between the input signal and the output signal through electromagnetic isolation or photoelectric isolation to prevent signal interference and electrical isolation. The principle of the digital isolator is to use a photocoupler or a magnetic isolator to convert the input signal into an optical signal or a magnetic signal, and then convert it back to a digital signal output. In this way, the electrical connection between the input signal and the output signal is effectively isolated, avoiding electrical interference that may occur during signal transmission.

[0073] The functions of digital isolators are mainly as follows. First, it can improve the reliability and stability of the system. By isolating the electrical connection between the input signal and the output signal, the digital isolator can prevent the influence of external noise and interference on the system, thereby ensuring the normal operation of the system.

[0074] Secondly, digital isolators can protect the safety of equipment and personnel. In some special environments, the input signal may contain dangerous factors such as high voltage and high current. If there are no proper isolation measures, it may cause damage to equipment and personnel. Digital isolators can effectively isolate these dangerous factors and ensure the safety of equipment and personnel.

[0075] In addition, digital isolators can also improve the transmission quality of signals. Since the electrical connection between the input signal and the output signal is isolated, digital isolators can reduce the interference and distortion that may occur during signal transmission, thereby improving the transmission quality and accuracy of the signal.

[0076] In short, the digital isolator is an important device, and its principle and function are crucial to ensuring the reliability, safety and signal transmission quality of the system. Through electromagnetic isolation or photoelectric isolation, the digital isolator can effectively isolate the electrical connection between the input signal and the output signal, thereby realizing signal isolation and transmission.

[0077] As shown in Figure 8, the reference voltage module includes:

[0078] The reference voltage chip U1 has an OUT pin connected to the feedback input terminal and the reference input terminal of the amplifier chip U3, and the VDD terminal and SHDN terminal of the reference voltage chip U1 are connected to the 3.3V input terminal through a capacitor filter module.

[0079] An energy storage BMS system includes the above-mentioned sampling circuit for shunt current detection, which stably transmits the collected voltage signal to the BMS main processing chip for current processing through an amplifier, a data acquisition-digital-to-analog converter, and a digital isolator, etc., and has accurate current detection and strong anti-interference ability.

[0080] It can be understood that the sampling circuit for shunt current detection can also be applied to current detection in a power battery pack, and is not limited to the energy storage battery system mentioned in the above embodiment, as long as it can complete the current detection during the battery charging and discharging process. The power battery pack is the battery that provides power for the tool, mostly referring to the storage battery that provides power for electric vehicles, electric trains, electric bicycles, etc.

[0081] In the description of this specification, the descriptions with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc., mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0082] 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.

[0083] The above-mentioned embodiments only express several 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. 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 sampling circuit for shunt current detection, characterized in that: The sampling circuit is used to collect the electrical signals at both ends of the shunt and convert the electrical signals into digital signals. The sampling circuit includes: A signal amplification module connected to the shunt, the signal amplification module is used to collect electrical signals at both ends of the shunt and enhance the strength and quality of the electrical signals; An analog-to-digital conversion module, the analog-to-digital conversion module is connected to the signal amplification module, and the analog-to-digital conversion module is used to convert the electrical signal output by the signal amplification module into a digital signal; A digital signal isolation module, the digital signal isolation module is connected to the analog-to-digital conversion module, and the digital signal isolation module is used to convert the digital signal output by the analog-to-digital conversion module into an isolated digital signal; A reference voltage module is connected to the signal amplification module and is used to provide a reference voltage to the signal amplification module.

2. The sampling circuit for shunt current detection according to claim 1, characterized in that: The signal amplification module comprises: An amplifier chip U3, wherein an enable input terminal of the amplifier chip U3 is connected to a pull-up resistor R27, an inverting input terminal of the amplifier chip U3 is connected to one end of the shunt, a positive input terminal of the amplifier chip U3 is connected to the other end of the shunt, a first filter module is connected between the positive input terminal of the amplifier chip U3 and the shunt, and a first filter module is connected between the reverse input terminal of the amplifier chip U3 and the shunt; A voltage regulator diode D9 is also connected between the shunt and the first filter module, the positive electrode of the voltage regulator diode D9 is grounded, and the negative electrode of the voltage regulator diode D9 is connected to one end of the shunt. A voltage regulator diode D8 is also connected between the shunt and the first filter module, the positive electrode of the voltage regulator diode D8 is grounded, and the negative electrode of the voltage regulator diode D8 is connected to the shunt; The common ground terminal of the amplifier chip U3 is grounded, the internal working voltage terminal of the amplifier chip U3 is grounded through the second filtering module, the output terminal of the amplifier chip U3 is connected to the resistor R1, the feedback input terminal of the amplifier chip U3 is connected to the output terminal of the amplifier chip U3 through the resistor R31, the reference input terminal of the amplifier chip is connected to the reference voltage through the resistor R33, the connection between the resistor R31 and the feedback input terminal of the amplifier chip U3 is connected to the resistor R32, and the other end of the resistor R32 is connected to the reference voltage.

3. The sampling circuit for shunt current detection according to claim 2, characterized in that: The first filtering module comprises: The first sub-filter module includes a capacitor C17 connected to the reverse input terminal of the amplifier chip U3, wherein the connection between the capacitor C17 and the reverse input terminal of the amplifier chip U3 is also connected to one end of a resistor R28, and the other end of the resistor R28 is connected to the shunt; The second sub-filter module includes a capacitor C25 connected to the positive input terminal of the amplifier chip U3, wherein the connection between the capacitor C25 and the positive input terminal of the amplifier chip U3 is also connected to one end of a resistor R30, and the other end of the resistor R30 is connected to the shunt; A capacitor C24 is also connected between the positive input terminal and the negative input terminal of the amplifier chip U3.

4. The sampling circuit for shunt current detection according to claim 2, characterized in that: The second filtering module comprises: Capacitor C18, one end of the capacitor C18 is connected to the internal working voltage terminal of the amplifier chip U3, the other end of the capacitor C18 is grounded, the connection between the capacitor C18 and the internal working voltage terminal of the amplifier chip U3 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the 3.3V input terminal, the connection between the resistor R5 and the 3.3V input terminal is connected to one end of the capacitor C26, and the other end of the capacitor C26 is grounded.

5. The sampling circuit for shunt current detection according to claim 1, characterized in that: The analog-to-digital conversion module comprises: An analog-to-digital converter chip U2, wherein the IN+ pin of the analog-to-digital converter chip U2 is connected to the output end of the amplifier chip U3 through a third filtering module, the VCC end of the analog-to-digital converter chip U2 is connected to a 3.3V input end, and a fourth filtering module for filtering out clutter is further connected at the connection between the VCC end and the 3.3V input end of the analog-to-digital converter chip U2, the IN- end of the analog-to-digital converter chip U2 is grounded through a resistor R14, the REF- end of the analog-to-digital converter chip U2 is grounded, and the GND end of the analog-to-digital converter chip U2 is grounded; The CS+ end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SDI end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SCK end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the SDO end of the analog-to-digital converter chip U2 is connected to the corresponding pin of the digital signal isolation module, the COMP end of the analog-to-digital converter chip U2 is grounded through capacitor C8, and the REFOUT end of the analog-to-digital converter chip U2 is grounded through capacitor C23.

6. The sampling circuit for shunt current detection according to claim 5, characterized in that: The third filtering module is used to filter the analog signal outputted from the output end of the amplifier chip U3, and the third filtering module includes: The third filtering module includes a resistor R6 and a capacitor C7 connected in parallel, one end of the resistor R6 is grounded, and the other end of the resistor R6 is connected to the IN+ pin of the analog-to-digital converter chip U2, one end of the capacitor C7 is grounded, and the other end of the capacitor C7 is connected to the IN+ pin of the analog-to-digital converter chip U2.

7. The sampling circuit for shunt current detection according to claim 5, characterized in that: The fourth filtering module is used to filter the current of the 3.3V input terminal, and the fourth filtering module includes: The fourth filtering module includes a capacitor C1 and a capacitor C2 connected in parallel, one end of the capacitor C1 is connected to the connection between the 3.3V input terminal and the VCC terminal of the amplifier chip U3, and the other end of the capacitor C1 is grounded.

8. The sampling circuit for shunt current detection according to claim 1, characterized in that: The digital signal isolation module comprises: A digital signal isolation chip U4, wherein the OUTA end of the digital signal isolation chip U4 is connected to the SDI end of the analog-to-digital converter chip U2, the OUTB end of the digital signal isolation chip U4 is connected to the SCK end of the analog-to-digital converter chip U2, the OUTC end of the digital signal isolation chip U4 is connected to the CS+ end of the analog-to-digital converter chip U2, the OUTD end of the digital signal isolation chip U4 is connected to the SDO end of the analog-to-digital converter chip U2, the INA, INB, INC and IND ends of the digital signal isolation chip U4 are connected to the 3.3V input end through an RC filtering module, and the VDD end of the digital signal isolation chip U4 is connected to the 3.3V input end through a capacitor filtering module.

9. The sampling circuit for shunt current detection according to claim 1, characterized in that: The reference voltage module comprises: The reference voltage chip U1 has an OUT pin connected to the feedback input terminal and the reference input terminal of the amplifier chip U3, and the VDD terminal and SHDN terminal of the reference voltage chip U1 are connected to the 3.3V input terminal through a capacitor filter module.

10. An energy storage battery management system, characterized in that: The method comprises at least one sampling circuit for shunt current detection according to any one of claims 1 to 9.

Images