Insulation detection circuit, battery management system, battery system, and vehicle

Abstract

The application relates to an insulation detection circuit, a battery management system, a battery system and a vehicle, which comprise a switching module with a first switching state and a second switching state, the switching module being connected with a positive electrode of a battery pack, a negative electrode of the battery pack and a vehicle body ground node respectively; a voltage division measurement module being connected with the switching module and the negative electrode of the battery pack respectively, the voltage division measurement module forming two voltage division measurement loops in the two switching states; an input end of an operational amplifier module being connected with a sampling resistor, the switching module and the negative electrode of the battery pack respectively; and a detection module being connected with an output end of the operational amplifier module, the detection module detecting a first voltage and a second voltage of the sampling resistor in the voltage division detection module in the two switching states, so as to obtain an insulation detection result according to the first voltage, the second voltage, the first voltage division measurement loop and the second voltage division measurement loop. Thus, the problems of a complex dual-path detection circuit structure, high cost and high failure rate are solved, the circuit structure can be simplified, and the cost can be saved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to an insulation detection circuit, a battery management system, a battery system, and a vehicle. Background Technology

[0002] Currently, most electric vehicle insulation testing circuits use dual-path testing, which separately tests the insulation resistance between the positive and negative busbars of the battery pack and the vehicle ground.

[0003] The specific method involves connecting a measuring resistor and a sampling resistor in parallel between the positive bus and the vehicle ground, and between the negative bus and the vehicle ground, respectively. The measurements are performed in two groups, positive and negative. The measurements are then output through the positive and negative modules and dual-channel detection is performed. The insulation resistance between the positive and negative buses and the vehicle ground is calculated using the voltage divider value.

[0004] However, the above method requires separate detection modules for both positive and negative outputs. This necessitates the use of an additional negative voltage power supply module, increasing the cost of dual-output detection and potentially leading to a higher failure rate. Furthermore, directly detecting and acquiring the voltage divider may introduce high voltage into other hardware components, interfering with their normal function and thus reducing the overall stability and accuracy of the system. Utility Model Content

[0005] This application provides an insulation detection circuit, a battery management system, a battery system, and a vehicle to solve the problem that dual-path detection circuits require an additional negative voltage power supply module, resulting in complex circuit structure, high cost, high failure rate, and the risk of high voltage introduction. This application only requires a single-path output detection to complete the insulation resistance measurement, simplifying the circuit structure and saving circuit costs.

[0006] The first aspect of this application provides an insulation detection circuit, including: The switching module includes a first switching state and a second switching state, and the switching module is connected to the positive terminal of the battery pack, the negative terminal of the battery pack, and the vehicle body grounding node, respectively. The voltage divider measurement module includes a sampling resistor. The voltage divider measurement module is connected to the negative terminal of the switch module and the battery pack, respectively. The voltage divider measurement module forms a first voltage divider measurement circuit when the switch module is in the first switch state, and forms a second voltage divider measurement circuit when the switch module is in the second switch state. An operational amplifier module, wherein the input terminals of the operational amplifier module are respectively connected to the sampling resistor, the switching module and the negative terminal of the battery pack; The detection module is connected to the output terminal of the operational amplifier module. When the switch module is in the first switch state, the detection module obtains the first voltage of the sampling resistor, and when the switch module is in the second switch state, it obtains the second voltage of the sampling resistor, so as to obtain the insulation detection result based on the first voltage, the second voltage, the first voltage divider measurement circuit, and the second voltage divider measurement circuit.

[0007] Optionally, the switching module includes: A first switch, one end of which is connected to the positive terminal of the battery pack, and the other end of which is connected to the voltage divider measurement module; The second switch has one end connected to the vehicle grounding node and the other end connected to the voltage divider measurement module. The third switch has one end connected to the negative terminal of the battery pack and the other end connected to the voltage divider measurement module.

[0008] Optionally, the voltage divider measurement module includes: The first voltage divider resistor unit has a first end connected to the other end of the first switch, a second end connected to the other end of the second switch, and a third end connected to the other end of the third switch. The second voltage divider resistor unit has one end connected to the second end of the first voltage divider resistor unit and the other end of the second switch, and the other end of the second voltage divider resistor unit is connected to the negative terminal of the battery pack.

[0009] Optionally, the first voltage divider resistor unit includes: A first measuring resistor, one end of which is connected to the other end of the first switch, and the other end of which is connected to the other end of the second switch; A second measuring resistor, one end of which is connected to the other end of the first switch and one end of the first measuring resistor, and the other end of the second measuring resistor is connected to the other end of the third switch; A third measuring resistor, one end of which is connected to the other end of the second measuring resistor and the other end of the third switch, and the other end of which is connected to the other end of the first measuring resistor.

[0010] Optionally, the second voltage divider resistor unit includes: A fourth measuring resistor, one end of which is connected to the other end of the second switch and the other end of the first measuring resistor, and the other end of which is connected to the negative terminal of the battery pack; The fifth measuring resistor has one end connected to the other end of the fourth measuring resistor and the other end of the second switch. A sampling resistor, one end of which is connected to the other end of the fifth measuring resistor, and the other end of which is connected to the negative terminal of the battery pack.

[0011] Optionally, the operational amplification module includes: A first capacitor, one end of which is connected to the other end of the fifth measuring resistor and one end of the sampling resistor, and the other end of the first capacitor is connected to the negative terminal of the battery pack; A sixth measuring resistor, one end of which is connected to one end of the first capacitor; The second capacitor has one end connected to the other end of the sixth measuring resistor, and the other end connected to the negative terminal of the battery pack. An operational amplifier, wherein the non-inverting input terminal of the operational amplifier is connected to the other end of the sixth measuring resistor and one end of the second capacitor, and the inverting input terminal of the operational amplifier is connected to the negative terminal of the battery pack; A protective resistor, one end of which is connected to the negative terminal of the battery pack, and the other end of which is connected to the ground wire; A current-limiting resistor, one end of which is connected to the output terminal of the operational amplifier, and the other end of which is connected to the detection module; The third capacitor has one end connected to the other end of the current-limiting resistor and the other end connected to the ground wire.

[0012] Optionally, the above-mentioned insulation detection circuit includes: An alarm module, connected to the detection module, is used to issue an alarm when the detection module detects that the output voltage of the operational amplifier module is not at a preset safety threshold.

[0013] A second aspect of this application provides a battery management system, including the insulation detection circuit described above.

[0014] A third aspect of this application provides a battery system, including the battery management system described above.

[0015] A fourth aspect of this application provides a vehicle including the battery system described above.

[0016] Therefore, the switching module forms a first switching state and a second switching state. The voltage divider measurement module forms a first voltage divider measurement circuit in the first switching state and a second voltage divider measurement circuit in the second switching state. The detection module detects the first voltage in the first voltage divider measurement circuit and the second voltage in the second voltage divider measurement circuit through the sampling resistor. The insulation detection result is obtained based on the first voltage, the second voltage, the first voltage divider measurement circuit, and the second voltage divider measurement circuit. This solves the problem that dual-channel detection circuits require an additional negative voltage power supply module, resulting in complex circuit structure, high cost, high failure rate, and the risk of high voltage introduction. This application only requires a single-channel output detection to complete the insulation resistance measurement, simplifying the circuit structure and saving circuit costs.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of an insulation detection circuit provided according to an embodiment of this application; Figure 2 This is a schematic diagram of an insulation detection circuit according to an embodiment of this application; Figure 3 This is a schematic diagram of a first voltage divider measurement circuit in a first switching state according to an embodiment of this application; Figure 4 This is a schematic diagram of a second voltage divider measurement circuit in a second switching state according to an embodiment of this application. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0020] The following description, with reference to the accompanying drawings, outlines an insulation detection circuit, a battery management system, a battery system, and a vehicle according to embodiments of this application. Addressing the issues mentioned in the background art, where dual-path detection circuits require an additional negative voltage power supply module, resulting in complex circuit structure, high cost, high failure rate, and the risk of high voltage introduction, this application provides an insulation detection circuit. In this method, a switching module forms a first switching state and a second switching state. A voltage divider measurement module forms a first voltage divider measurement loop in the first switching state and a second voltage divider measurement loop in the second switching state. A detection module detects the first voltage in the first voltage divider measurement loop and the second voltage in the second voltage divider measurement loop using a sampling resistor. The insulation detection result is obtained based on the first voltage, the second voltage, the first voltage divider measurement loop, and the second voltage divider measurement loop. This solves the problem of dual-path detection circuits requiring an additional negative voltage power supply module, leading to complex circuit structure, high cost, high failure rate, and the risk of high voltage introduction. This application only requires a single-path output detection to complete the insulation resistance measurement, simplifying the circuit structure and saving circuit costs.

[0021] Specifically, Figure 1 This is a schematic diagram of an insulation detection circuit provided in an embodiment of this application.

[0022] like Figure 1 As shown, the insulation detection circuit 10 includes: a switching module 100, a voltage divider measurement module 200, an operational amplifier module 300, and a detection module 400.

[0023] The system includes a switch module 100, which has a first switch state and a second switch state. The switch module 100 is connected to the positive terminal of the battery pack, the negative terminal of the battery pack, and the vehicle body grounding terminal, respectively. A voltage divider measurement module 200 includes a sampling resistor R1. The voltage divider measurement module 200 is connected to the switch module 100 and the negative terminal of the battery pack, respectively. When the switch module 100 is in the first switch state, the voltage divider measurement module 200 forms a first voltage divider measurement circuit; when the switch module 100 is in the second switch state, the voltage divider measurement module 200 forms a second voltage divider measurement circuit. Measurement circuit; operational amplifier module 300, the input terminal of operational amplifier module 300 is connected to sampling resistor R1, switch module 100 and the negative terminal of battery pack respectively; detection module 400, the detection module 400 is connected to the output terminal of operational amplifier module 300, the detection module 400 obtains the first voltage of sampling resistor R1 when switch module 100 is in the first switching state, and obtains the second voltage of sampling resistor R1 when switch module 100 is in the second switching state, so as to obtain the insulation detection result based on the first voltage, the second voltage, the first voltage divider measurement circuit and the second voltage divider measurement circuit.

[0024] Specifically, such as Figure 1As shown, the purpose of this embodiment is to measure the resistance Rp between the positive terminal of the vehicle battery pack and the vehicle body ground, and the resistance Rn between the negative terminal of the vehicle battery pack and the vehicle body ground. Rp and Rn represent vehicle body characteristics, the battery pack is a Ubat, and the vehicle battery pack is connected to the Battery Management System (BMS) via a switching module 100. When the BMS is connected to a high-voltage power supply, it is connected to the voltage divider measurement module 200. The voltage divider measurement module 200 forms two different voltage divider circuits by switching the third switch in the switching module 100. Subsequently, the operational amplifier module 300 transmits the voltage value across the sampling resistor R1 in the voltage divider measurement module 200 to the analog-to-digital converter (ADC) module for detection. Finally, based on the two voltage values ​​collected by the sampling resistor R1 under different switching states, the insulation resistance between the positive and negative busbars and the vehicle body ground is calculated.

[0025] In practical implementation, this application incorporates measuring resistors between the positive and negative busbars of the battery pack input and the vehicle ground. Voltage division between the positive and negative busbars and the vehicle ground is collected using a resistor divider. A two-channel output detection module composed of operational amplifiers then outputs the collected voltage divisions to an ADC module for detection and calculation to determine the insulation resistance between the positive and negative busbars and the vehicle ground. Thus, by controlling the voltage division output detection circuit between the positive and negative terminals of the battery pack and the vehicle ground via a switch, the positive and negative voltage division measurement modules are combined into a single circuit through the opening and closing of the switch, eliminating the negative voltage output detection module and achieving single-channel output detection. Furthermore, the operational amplifier module utilizes its isolation characteristics to separate the voltage division acquisition and output detection parts, preventing high voltage coupling to other hardware components and ensuring system stability.

[0026] Optionally, in some embodiments, the switch module 100 includes: a first switch S1A, a second switch S2A, and a third switch S3A.

[0027] The first switch S1A has one end connected to the positive terminal of the battery pack and the other end connected to the voltage divider measurement module 200; the second switch S2A has one end connected to the vehicle body grounding node and the other end connected to the voltage divider measurement module 200; the third switch S3A has one end connected to the negative terminal of the battery pack and the other end connected to the voltage divider measurement module 200.

[0028] Among them, the first switch S1A, the second switch S2A and the third switch S3A can be optocouplers, MOSFETs and transistors.

[0029] Specifically, the first switch S1A is the switch between the positive terminal of the battery pack and the battery management system, the second switch S2A is the switch between the vehicle ground and the BMS, and the actual design circuit of the BMS is on the right side of the two switches. The on / off connection between the BMS and the vehicle high voltage is controlled by software commands to ensure that the BMS is isolated from the high voltage when it is not in use. The third switch S3A is the switch for switching the voltage divider detection circuit. The voltage divider detection module 200 forms the first voltage divider measurement circuit and the second voltage divider measurement circuit through the two states of open and closed.

[0030] Optionally, in some embodiments, the voltage divider measurement module 200 includes: a first voltage divider resistor unit and a second voltage divider resistor unit.

[0031] The first voltage divider resistor unit has its first end connected to the other end of the first switch S1A, its second end connected to the other end of the second switch S2A, and its third end connected to the other end of the third switch S3A. The second voltage divider resistor unit has one end connected to the second end of the first voltage divider resistor unit and the other end of the second switch S2A, and its other end connected to the negative terminal of the battery pack.

[0032] Furthermore, in some embodiments, the first voltage divider resistor unit includes: a first measuring resistor Rp1, a second measuring resistor Rp2, and a second measuring resistor Rp3.

[0033] Specifically, the first measuring resistor Rp1 has one end connected to the other end of the first switch S1A and the other end connected to the other end of the second switch S2A; the second measuring resistor Rp2 has one end connected to the other end of the first switch S1A and one end of the first measuring resistor Rp1, and the other end connected to the other end of the third switch S3A; the second measuring resistor Rp3 has one end connected to the other end of the second measuring resistor Rp2 and the other end of the third switch S3A, and the other end connected to the other end of the first measuring resistor Rp1.

[0034] Furthermore, in some embodiments, the second voltage divider resistor unit includes: a fourth measuring resistor Rp4, a fifth measuring resistor Rp5, and a sampling resistor R1.

[0035] Among them, the fourth measuring resistor Rp4 has one end connected to the other end of the second switch S2A and the other end of the first measuring resistor Rp1, and the other end of the fourth measuring resistor Rp4 is connected to the negative terminal of the battery pack; the fifth measuring resistor Rp5 has one end connected to the other end of the fourth measuring resistor Rp4 and the other end of the second switch S2A; the sampling resistor R1 has one end connected to the other end of the fifth measuring resistor Rp5, and the other end of the sampling resistor R1 is connected to the negative terminal of the battery pack.

[0036] Specifically, after passing through switches S1A and S2A, the positive and negative terminals of the battery pack are connected in parallel between the positive bus and the vehicle ground with a first measuring resistor Rp1 of MΩ level. From the positive bus to the vehicle ground, the second measuring resistors Rp2 and Rp3 of kΩ level are connected in sequence. The fourth measuring resistor Rp4 of MΩ level is connected in parallel between the negative bus and the vehicle ground. From the vehicle ground to the negative bus, the fifth measuring resistor R3 of kΩ level and the sampling resistor R1 are connected in sequence.

[0037] Optionally, the operational amplifier module 300 includes: a first capacitor C1, a sixth measuring resistor Rp6, a second capacitor C2, an operational amplifier U1, a protection resistor R2, a current limiting resistor R3, and a third capacitor C3.

[0038] Among them, the first capacitor C1 has one end connected to the other end of the fifth measuring resistor Rp5 and one end of the sampling resistor R1, and the other end of the first capacitor C1 is connected to the negative terminal of the battery pack; the sixth measuring resistor Rp6 has one end connected to one end of the first capacitor C1; the second capacitor C2 has one end connected to the other end of the sixth measuring resistor Rp6, and the other end of the second capacitor C2 is connected to the negative terminal of the battery pack; the operational amplifier U1 has its non-inverting input terminal connected to the sixth measuring resistor Rp5 and one end of the sampling resistor R1. The other end of resistor Rp6 is connected to one end of the second capacitor C2, and the inverting input terminal of operational amplifier U1 is connected to the negative terminal of the battery pack; protection resistor R2, one end of protection resistor R2 is connected to the negative terminal of the battery pack, and the other end of protection resistor R2 is connected to the ground wire; current limiting resistor R3, one end of current limiting resistor R3 is connected to the output terminal of operational amplifier U1, and the other end of current limiting resistor R3 is connected to the detection module 400; third capacitor C3, one end of third capacitor C3 is connected to the other end of current limiting resistor R3, and the other end of third capacitor C3 is connected to the ground wire.

[0039] Specifically, in this embodiment, a sixth measuring resistor Rp6 and a first capacitor C1 are connected across the sampling resistor R1 to form a Π-type filter. One end of the sixth measuring resistor Rp6 is connected to the fifth measuring resistor Rp5 and the sampling resistor R1, and the other end of the sixth measuring resistor Rp6 is connected to the positive input terminal of the operational amplifier U1. A protection resistor R2 is connected between the negative bus and the inverting input terminal of the operational amplifier U1. VCC provides the operating voltage for the operational amplifier U1, and the negative power supply terminal is grounded. The second capacitor C2 is the filter capacitor between the positive input and output terminals of the operational amplifier U1. The third capacitor C3 is the decoupling capacitor before the detection module 400. The current limiting resistor R3 and the third capacitor C3 are connected to the detection module 400. An operational amplifier module 300 is used between the detection module 400 and the voltage divider measurement module 200 to isolate the detection module 400 and prevent high voltage from being directly introduced into the detection module 400. Then, the operational amplifier module 300 transmits the two voltage values ​​of the sampling resistor R1 in different circuits to the detection module 400 and calculates the insulation resistance between the positive and negative buses and the vehicle body ground through a control strategy.

[0040] In actual implementation, the embodiments of this application form two voltage divider measurement modules 200 by opening and closing the switch module 100, and collect two voltages of the sampling resistors in the two voltage divider measurement modules by the operational amplifier module 400.

[0041] (1) When both switches S1A and S2A are closed, the BMS is connected to the vehicle's high voltage and the vehicle body ground. At this time, the software controls the switch S3A to open, forming the following... Figure 3 The first voltage divider circuit shown is such that the positive bus of the battery pack and the vehicle ground form a circuit Rp / / Rp1 / / (Rp2+Rp3), and the negative bus and the vehicle ground form a circuit Rn / / Rp4 / / (Rp5+R1). According to the voltage divider principle and Kirchhoff's laws, the relationship between Rp and Rn is obtained as Equation 1.

[0042] According to the principle of voltage division: (1) (2) By Kirchhoff's theorem: (3) Based on formulas (1), (2), and (3), we obtain the first equation relating Rp and Rn: (4) in, for Voltage at both ends, for Voltage at both ends, for The voltages collected at both ends.

[0043] (2) When both switches S1A and S2A are closed, the BMS is connected to the vehicle's high voltage and the vehicle body ground. At this time, the software controls the closing of switch S3A, then... Figure 4 The second voltage divider measurement circuit shown here forms an overall circuit between the positive and negative busbars and the vehicle ground [(Rp / / Rp1)+Rn / / Rp4 / / Rp3 / / (Rp5+R1)] / / Rp2. Based on the voltage divider principle and Kirchhoff's laws, the relationship between Rp and Rn is obtained as Equation 2.

[0044] According to the principle of voltage division: = (5) (6) By Kirchhoff's theorem: (7) Based on formulas (5), (6), and (7), we obtain equation 2, which relates Rp and Rn: (8) The working states 1 and 2 are changed once at fixed intervals. The voltage values ​​of R4 under the two different states are collected. The relationship between Rp and Rn, i.e., formula (4) and formula (8), are combined to calculate Rp (insulation resistance between the positive bus and the vehicle body ground) and Rn (insulation resistance between the negative bus and the vehicle body ground).

[0045] ; .

[0046] Optionally, the insulation detection circuit 10 described above includes an alarm module.

[0047] The alarm module is connected to the detection module 400 and is used to issue an alarm when the detection module 400 detects that the output voltage of the operational amplifier module 300 is not at a preset safety threshold.

[0048] Specifically, the preset safety threshold can be set by the user, obtained through a limited number of experiments, or obtained through a limited number of computer simulations. No specific limitation is made here. If the detection module 400 detects that the output voltage is not at the preset safety threshold, there may be a risk of leakage or insulation damage, and the alarm module will issue an alarm.

[0049] According to the insulation detection circuit proposed in this application, a switching module forms a first switching state and a second switching state. A voltage divider measurement module forms a first voltage divider measurement loop in the first switching state and a second voltage divider measurement loop in the second switching state. A detection module detects the first voltage in the first voltage divider measurement loop and the second voltage in the second voltage divider measurement loop using a sampling resistor. The insulation detection result is obtained based on the first voltage, the second voltage, the first voltage divider measurement loop, and the second voltage divider measurement loop. This solves the problem that dual-channel detection circuits require an additional negative voltage power supply module, leading to complex circuit structure, high cost, high failure rate, and the risk of high voltage introduction. This application only requires a single-channel output detection to complete the insulation resistance measurement, simplifying the circuit structure and saving circuit costs.

[0050] This application also provides a battery management system, including the above-described insulation detection circuit.

[0051] According to the battery management system proposed in the embodiments of this application, the above-mentioned insulation detection circuit solves the problem that the dual-channel detection circuit requires an additional negative voltage power supply module, which leads to complex circuit structure, high cost, high failure rate, and high voltage introduction risk. This application only requires a single-channel output detection to complete the insulation resistance measurement, simplifying the circuit structure and saving circuit cost.

[0052] This application also provides a battery system, including the battery management system described above.

[0053] According to the battery system proposed in the embodiments of this application, the above-mentioned battery management system solves the problem that the dual-channel detection circuit requires an additional negative voltage power supply module, which leads to complex circuit structure, high cost, high failure rate, and the risk of high voltage introduction. This application only requires a single-channel output detection to complete the measurement of insulation resistance, simplifying the circuit structure and saving circuit costs.

[0054] This application also provides a vehicle, including: the battery system described above. According to the vehicle proposed in the embodiments of this application, the battery system described above solves the problem that the dual-path detection circuit requires an additional negative voltage power supply module, which leads to complex circuit structure, high cost, high failure rate, and the risk of high voltage introduction. This application only requires a single-path output detection to complete the insulation resistance measurement, simplifying the circuit structure and saving circuit costs.

[0055] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0058] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0059] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0060] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An insulation detection circuit, characterized in that, include: The switch module includes a first switch state and a second switch state, and the switch module is connected to the positive terminal of the battery pack, the negative terminal of the battery pack, and the vehicle body grounding node, respectively. The voltage divider measurement module includes a sampling resistor. The voltage divider measurement module is connected to the negative terminal of the switch module and the battery pack, respectively. The voltage divider measurement module forms a first voltage divider measurement circuit when the switch module is in the first switch state, and forms a second voltage divider measurement circuit when the switch module is in the second switch state. An operational amplifier module, wherein the input terminals of the operational amplifier module are respectively connected to the sampling resistor, the switching module and the negative terminal of the battery pack; The detection module is connected to the output terminal of the operational amplifier module. When the switch module is in the first switch state, the detection module obtains the first voltage of the sampling resistor, and when the switch module is in the second switch state, it obtains the second voltage of the sampling resistor, so as to obtain the insulation detection result based on the first voltage, the second voltage, the first voltage divider measurement circuit, and the second voltage divider measurement circuit.

2. The insulation detection circuit according to claim 1, characterized in that, The switching module includes: A first switch, one end of which is connected to the positive terminal of the battery pack, and the other end of which is connected to the voltage divider measurement module; The second switch has one end connected to the vehicle grounding node and the other end connected to the voltage divider measurement module. The third switch has one end connected to the negative terminal of the battery pack and the other end connected to the voltage divider measurement module.

3. The insulation detection circuit according to claim 2, characterized in that, The voltage divider measurement module includes: The first voltage divider resistor unit has a first end connected to the other end of the first switch, a second end connected to the other end of the second switch, and a third end connected to the other end of the third switch. The second voltage divider resistor unit has one end connected to the second end of the first voltage divider resistor unit and the other end of the second switch, and the other end of the second voltage divider resistor unit is connected to the negative terminal of the battery pack.

4. The insulation detection circuit according to claim 3, characterized in that, The first voltage divider resistor unit includes: A first measuring resistor, one end of which is connected to the other end of the first switch, and the other end of which is connected to the other end of the second switch; A second measuring resistor, one end of which is connected to the other end of the first switch and one end of the first measuring resistor, and the other end of the second measuring resistor is connected to the other end of the third switch; A third measuring resistor, one end of which is connected to the other end of the second measuring resistor and the other end of the third switch, and the other end of which is connected to the other end of the first measuring resistor.

5. The insulation detection circuit according to claim 3, characterized in that, The second voltage divider resistor unit includes: A fourth measuring resistor, one end of which is connected to the other end of the second switch and the other end of the first measuring resistor, and the other end of which is connected to the negative terminal of the battery pack; The fifth measuring resistor has one end connected to the other end of the fourth measuring resistor and the other end of the second switch. A sampling resistor, one end of which is connected to the other end of the fifth measuring resistor, and the other end of which is connected to the negative terminal of the battery pack.

6. The insulation detection circuit according to claim 1, characterized in that, The operational amplification module includes: A first capacitor, one end of which is connected to the other end of the fifth measuring resistor and one end of the sampling resistor, and the other end of the first capacitor is connected to the negative terminal of the battery pack; A sixth measuring resistor, one end of which is connected to one end of the first capacitor; The second capacitor has one end connected to the other end of the sixth measuring resistor, and the other end connected to the negative terminal of the battery pack. An operational amplifier, wherein the non-inverting input terminal of the operational amplifier is connected to the other end of the sixth measuring resistor and one end of the second capacitor, and the inverting input terminal of the operational amplifier is connected to the negative terminal of the battery pack; A protective resistor, one end of which is connected to the negative terminal of the battery pack, and the other end of which is connected to the ground wire; A current-limiting resistor, one end of which is connected to the output terminal of the operational amplifier, and the other end of which is connected to the detection module; The third capacitor has one end connected to the other end of the current-limiting resistor and the other end connected to the ground wire.

7. The insulation detection circuit according to claim 1, characterized in that, include: An alarm module, connected to the detection module, is used to issue an alarm when the detection module detects that the output voltage of the operational amplifier module is not at a preset safety threshold.

8. A battery management system, characterized in that, The insulation detection circuit includes any one of claims 1-7.

9. A battery system, characterized in that, Includes the battery management system as described in claim 8.

10. A vehicle, characterized in that, include: The battery system as described in claim 9.

Images