Isolation circuit, battery management system and battery pack

Abstract

The utility model provides an isolating circuit, a battery management system and a battery pack, the isolating circuit comprises a first isolation belt and a second isolation belt, the first isolation belt is arranged between a processing unit and a first reference point in a sampling unit, and the second isolation belt is arranged between the processing unit and a second reference point in the sampling unit. The high-low voltage isolation module is used for realizing high-low voltage isolation between a first reference point and a second reference point; and through the two isolation belts, the voltage isolation requirement of a high-voltage platform can be met, the high-voltage and low-voltage isolation capability of the isolation circuit is also improved, and the reliability of the battery management system is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to an isolation circuit, a battery management system and a battery pack. Background Art

[0002] The Battery Management System (BMS) is a device installed in the power battery of an electric vehicle to monitor, evaluate and manage the power battery. The printed circuit board (PCB) in the BMS contains both high-voltage and low-voltage circuits, and data communication is required between the high-voltage and low-voltage circuits. To ensure safety, the high-voltage side needs to be isolated from the low-voltage side.

[0003] Considering the efficiency of energy storage and transmission, and reducing the size and weight of transmission lines, the platform voltage used in energy storage systems is increasing. However, the current high and low voltage isolation solutions cannot meet the isolation requirements of high voltage platforms. Utility Model Content

[0004] The utility model mainly provides an isolation circuit, a battery management system and a battery pack, which can not only meet the isolation requirements of the high-voltage platform, but also improve the high- and low-voltage isolation capabilities of the isolation circuit, thereby optimizing the reliability of the BMS.

[0005] The technical solution of the utility model is achieved in this way:

[0006] In the first aspect, an embodiment of the utility model provides an isolation circuit, the isolation circuit comprising a first isolation zone and a second isolation zone, wherein: the first isolation zone is arranged between a first reference point in a processing unit and a sampling unit, and the second isolation zone is arranged between a second reference point in the processing unit and the sampling unit, for realizing high and low voltage isolation between the first reference point and the second reference point.

[0007] Through the above technical means, a first isolation belt and a second isolation belt connected in series are set between a first reference point and a second reference point where high and low voltage isolation is required. By connecting the two-stage isolation belts in series and equalizing the voltage, the isolation circuit can meet the isolation requirements of the high-voltage platform, improve the high and low voltage isolation capability of the isolation circuit, and optimize the reliability of the BMS.

[0008] In some embodiments, the sampling unit includes a first sampling circuit and a second sampling circuit, wherein: the first sampling circuit is used to sample the voltage between the high-voltage positive terminal and the first reference point and between the second reference point and the first reference point to determine the first sampling data; the second sampling circuit is used to sample the voltage between the high-voltage positive terminal and the second reference point to determine the second sampling data.

[0009] Through the above technical means, voltage sampling is performed through the first sampling circuit and the second sampling circuit to respectively determine the first sampling data and the second sampling data, so that the operator can know the situation of the isolation circuit.

[0010] In some embodiments, the first isolation zone includes a first isolation communication unit and a first isolation power supply, wherein: the first isolation power supply is used to supply power to the first sampling circuit; the first isolation communication unit is used to receive first sampling data sent by the first sampling circuit and send the first sampling data to the processing unit to achieve isolated communication between the first sampling circuit and the processing unit.

[0011] Through the above technical means, the first isolated power supply and the first isolated communication unit are used as the first isolation zone to isolate the high and low voltages between the first sampling circuit and the processing unit. Through this two-stage series isolation method, the high and low voltage isolation capabilities of the isolation circuit are improved, and the reliability of the isolation circuit is optimized.

[0012] In some embodiments, the second isolation zone includes a second isolation communication unit and a second isolation power supply, wherein: the second isolation power supply is used to supply power to the second sampling circuit; the second isolation communication unit is used to receive second sampling data sent by the second sampling circuit and send the second sampling data to the processing unit to achieve isolated communication between the second sampling circuit and the processing unit.

[0013] Through the above technical means, the second isolated power supply and the second isolated communication unit are used as the second isolation zone to isolate the second sampling circuit from the processing unit. Through this two-stage series isolation method, the high and low voltage isolation capability of the isolation circuit is improved and the reliability of the isolation circuit is optimized.

[0014] In some embodiments, the isolation circuit further includes a first resistor, wherein: a first end of the first resistor is connected to a third reference point of the processing unit, and a second end of the first resistor is connected to a second reference point in the sampling unit, for clamping the potential of the third reference point of the processing unit.

[0015] Through the above technical means, by setting the first resistor, the accumulated charge on the processing unit is exported, which solves the risk of insulation failure caused by local discharge of the processing unit in the above two-stage series isolation high and low voltage isolation scheme, and improves the safety and stability of the isolation circuit.

[0016] In some embodiments, the isolation circuit further includes a second resistor, wherein: a first end of the second resistor is connected to the third reference point of the processing unit, and a second end of the second resistor is connected to the first reference point in the sampling unit.

[0017] Through the above-mentioned technical means, by setting the second resistor and the first resistor, the equivalent impedance of the first isolation zone and the second isolation zone can be made equal, thereby avoiding damage to the isolation zone due to uneven voltage division, solving the system reliability problem caused by uneven voltage division, and improving the safety and stability of the circuit.

[0018] In some embodiments, the first sampling circuit includes a third resistor, a fourth resistor, a fifth resistor and a sixth resistor, and the second sampling circuit includes a seventh resistor and an eighth resistor, wherein: the first end of the third resistor is connected to the high-voltage positive terminal, the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the fifth resistor is connected to the second reference point, the second end of the fifth resistor is connected to the first end of the sixth resistor, the second end of the fourth resistor and the second end of the sixth resistor are connected to the first reference point; the first end of the seventh resistor is connected to the second reference point, the second end of the seventh resistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the high-voltage positive terminal.

[0019] Through the above technical means, by setting the third resistor, the fourth resistor, the fifth resistor and the sixth resistor in the first sampling circuit, and setting the seventh resistor and the eighth resistor in the second sampling circuit, it is convenient to set sampling points at different positions for high-voltage sampling, thereby realizing insulation detection and calculation of equivalent impedance.

[0020] In some embodiments, a first voltage sampling point is provided between the second end of the third resistor and the first end of the fourth resistor, for performing voltage sampling between the high voltage positive terminal and the first reference point; a second voltage sampling point is provided between the second end of the fifth resistor and the first end of the sixth resistor, for performing voltage sampling between the second reference point and the first reference point; a third voltage sampling point is provided between the second end of the seventh resistor and the first end of the eighth resistor, for performing voltage sampling between the high voltage positive terminal and the second reference point.

[0021] Through the above technical means, by setting a first voltage sampling point between the high-voltage positive terminal and the first reference point, the voltage value between the high-voltage positive terminal and the first reference point is determined; and setting a second voltage sampling point between the second reference point and the first reference point to determine the voltage value between the second reference point and the first reference point; setting a third voltage sampling point between the high-voltage positive terminal and the second reference point to determine the voltage value between the high-voltage positive terminal and the second reference point, thereby realizing insulation detection and calculation of equivalent impedance according to the voltage values ​​of the above three reference points.

[0022] In some embodiments, the first sampling circuit includes a fifth resistor, a sixth resistor and a ninth resistor, and the second sampling circuit includes a seventh resistor and an eighth resistor, wherein: the first end of the ninth resistor is connected to the high-voltage positive terminal, the first end of the fifth resistor is connected to the second reference point, the second end of the fifth resistor is connected to the first end of the sixth resistor, the second end of the ninth resistor and the second end of the sixth resistor are connected to the first reference point; the first end of the seventh resistor is connected to the second reference point, the second end of the seventh resistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the high-voltage positive terminal.

[0023] Through the above technical means, by setting the fifth resistor and the sixth resistor in the first sampling circuit and the seventh resistor and the eighth resistor in the second sampling circuit, it is convenient to set sampling points at different positions for high-voltage sampling, thereby realizing insulation detection and calculation of equivalent impedance.

[0024] In some embodiments, a second voltage sampling point is provided between the second end of the fifth resistor and the first end of the sixth resistor, for performing voltage sampling between the second reference point and the first reference point; a third voltage sampling point is provided between the second end of the seventh resistor and the first end of the eighth resistor, for performing voltage sampling between the high voltage positive terminal and the second reference point.

[0025] Through the above technical means, by setting a second voltage sampling point between the second reference point and the first reference point, the voltage value between the second reference point and the first reference point is determined; by setting a third voltage sampling point between the high-voltage positive terminal and the second reference point, the voltage value between the high-voltage positive terminal and the second reference point is determined, thereby realizing insulation detection and equivalent impedance calculation based on the voltage values ​​of the above two reference points.

[0026] In some embodiments, the first sampling circuit includes a third resistor, a fourth resistor, a fifth resistor and a sixth resistor, and the second sampling circuit includes a tenth resistor, wherein: the first end of the third resistor is connected to the high-voltage positive terminal, the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the fifth resistor is connected to the second reference point, the second end of the fifth resistor is connected to the first end of the sixth resistor, the second end of the fourth resistor and the second end of the sixth resistor are connected to the first reference point; the first end of the tenth resistor is connected to the second reference point, and the second end of the tenth resistor is connected to the high-voltage positive terminal.

[0027] Through the above technical means, by setting the third resistor, the fourth resistor, the fifth resistor and the sixth resistor in the first sampling circuit, it is convenient to set sampling points at different positions for high voltage sampling, thereby realizing insulation detection and calculation of equivalent impedance.

[0028] In some embodiments, a first voltage sampling point is provided between the second end of the third resistor and the first end of the fourth resistor, for performing voltage sampling between the high voltage positive terminal and the first reference point; a second voltage sampling point is provided between the second end of the fifth resistor and the first end of the sixth resistor, for performing voltage sampling between the second reference point and the first reference point.

[0029] Through the above technical means, by setting a first voltage sampling point between the high-voltage positive terminal and the first reference point, the voltage value between the high-voltage positive terminal and the first reference point is determined; and by setting a second voltage sampling point between the second reference point and the first reference point, the voltage value between the second reference point and the first reference point is determined, thereby realizing insulation detection and calculation of equivalent impedance according to the voltage values ​​of the above three reference points.

[0030] In some embodiments, the sampling unit further includes a first equivalent resistor and a second equivalent resistor, wherein:

[0031] The first equivalent resistance is the equivalent impedance between the high voltage positive terminal and the second reference point, and the second equivalent resistance is the equivalent impedance between the first reference point and the second reference point;

[0032] The first equivalent resistance and the second equivalent resistance are jointly determined according to the sampling voltages of the first voltage sampling point, the second voltage sampling point and the third voltage sampling point.

[0033] Through the above technical means, by setting multiple voltage sampling points between the high-voltage positive terminal, the first reference point, and the second reference point, the resistance value of the first equivalent resistor and the resistance value of the second equivalent resistor are determined according to the voltage values ​​collected by the multiple voltage sampling points. This can facilitate operators to grasp the voltage situation of the isolation circuit and facilitate further calculation and analysis of the isolation circuit.

[0034] In a second aspect, an embodiment of the utility model provides a battery management system, which includes a processing unit, a sampling unit and an isolation circuit as described in the first aspect, wherein: the isolation circuit is connected between the processing unit and the sampling unit.

[0035] Through the above technical means, the voltage isolation capability of the isolation circuit is improved and the reliability of the battery management system is optimized by connecting two-stage isolation belts in series for voltage balancing.

[0036] In a third aspect, an embodiment of the utility model provides a battery pack, comprising a battery and the battery management system described in the second aspect; wherein the battery is connected between the high-voltage positive terminal and the first reference point.

[0037] Through the above-mentioned technical means, the high and low voltage isolation requirements of the output high voltage platform can be met, ensuring that the battery pack can still operate normally and reliably at a higher voltage.

[0038] The utility model provides an isolation circuit, a battery management system and a battery pack, wherein a first isolation belt and a second isolation belt connected in series are arranged between a first reference point and a second reference point where high and low voltage isolation is required. By means of the two-stage isolation belts being connected in series and voltage equalization, the isolation circuit can meet the voltage isolation requirements of the high-voltage platform, while improving the high and low voltage isolation capabilities of the isolation circuit, thereby improving the reliability of the battery management system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the composition structure of an isolation circuit;

[0040] Figure 2 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 1 ;

[0041] Figure 3 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 2 ;

[0042] Figure 4 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 3 ;

[0043] Figure 5 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 4 ;

[0044] Figure 6 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 5 ;

[0045] Figure 7 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 6 ;

[0046] Figure 8 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 7 ;

[0047] Fig. 9 A schematic diagram of the structure of a battery pack provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0048] In order to more thoroughly understand the features and technical contents of the embodiments of the present invention, the implementation of the embodiments of the present invention is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not intended to limit the embodiments of the present invention.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the field of the present invention. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0050] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0051] It should also be pointed out that the terms "first\second\third" involved in the embodiments of the present invention are only used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present invention described here can be implemented in an order other than that illustrated or described here.

[0052] New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also being increasingly used in energy storage fields.

[0053] At present, new energy batteries are increasingly used in life and industry. New energy batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0054] In the embodiments of the utility model, the battery may be a battery cell. A battery cell refers to a basic unit that can realize the mutual conversion between chemical energy and electrical energy, and can be used to make a battery module or a battery pack, so as to supply power to an electrical device. A battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged. The battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present disclosure are not limited to this.

[0055] In the embodiment of the utility model, the battery can also be a single physical module including one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in mixed connection through a busbar component.

[0056] BMS is an indispensable core part of electric vehicles, which can monitor the voltage, current, temperature and other state quantities of the power battery in electric vehicles. At present, there are high-voltage circuits and low-voltage circuits on the PCB board in BMS at the same time, and data communication is required between the high-voltage circuit and the low-voltage circuit. The voltage, temperature and other signals collected from the high-voltage circuit are transmitted to the microcontroller unit (MCU) in the low-voltage circuit for logic strategy processing, or the MCU in the low-voltage circuit transmits the control signal to the high-voltage circuit. In order to ensure the safety of the low-voltage circuit and the personal safety of the operator, an isolation communication chip is generally used to achieve normal communication between the high-voltage circuit and the low-voltage circuit and high-low voltage isolation.

[0057] Figure 1 Figure 1 is a schematic diagram of the structure of an isolation circuit. Figure 1 As shown, in the related art, the high-voltage sampling circuit 101 is the high-voltage side, and the microcontroller unit 102, that is, the MCU is the low-voltage side. Among them, the high-voltage sampling circuit 101 is connected to the positive terminal of the power battery through the high-voltage positive terminal, which can also be called the HV+ terminal; the high-voltage sampling circuit 101 is connected to the negative terminal of the power battery through the high-voltage negative terminal, which can also be called the U00 (HV-) terminal; the high-voltage sampling circuit 101 includes multiple resistors such as resistors R11, R12, R13, R14, R15, R16, R17, R18, R19, and R20. The high-voltage sampling circuit 101 also includes multiple metal-oxide semiconductor field-effect transistors (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), such as the first MOS tube M1 and the second MOS tube M2, etc., which are used to perform high-voltage sampling on the circuit through the voltage sampling point V11, the voltage sampling point V12, and the voltage sampling point V13 based on the cooperation of the above multiple resistors and multiple MOS tubes. In addition, the ground terminal is set on the microcontroller unit 102 side. The resistance Rp is the insulation equivalent resistance of the high voltage positive terminal to the ground, and the resistance Rn is the insulation equivalent resistance of the high voltage negative terminal to the ground.

[0058] like Figure 1 , the isolated power supply 104 and the isolated communication chip 103 together constitute the isolation belt of the high-voltage sampling circuit 101 to the earth, which is connected in parallel between the high-voltage positive terminal, the high-voltage negative terminal and the ground terminal. Under normal circumstances, the insulation equivalent resistance Rp and Rn are not equal, resulting in a short circuit on the insulation equivalent resistance Rp side or the insulation equivalent resistance Rn side, that is, a unilateral insulation short circuit occurs. In this case, the voltage at the ground terminal is equal to the platform voltage, that is, the high-voltage positive terminal HV+ or the high-voltage negative terminal U00, and the isolation belt will withstand all the high voltage on the high-voltage sampling circuit 101 side. Therefore, the voltage that the isolation belt can withstand needs to match the voltage on the high-voltage sampling circuit 101 side to ensure the normal operation of the circuit on the low-voltage side.

[0059] According to the energy storage system industry standards, the isolation communication chips currently available in the industrial market can meet the voltage isolation requirements of a high-voltage platform of up to 1.5KV. Figure 1 In the solution shown, an isolation belt is connected in series between the high-voltage sampling circuit 101 and the microcontroller unit 102. When the insulation of the high-voltage positive terminal deteriorates or decreases, the voltage difference between the high-voltage negative terminal and the ground terminal increases, and the maximum steady-state voltage can reach the platform voltage Upd. Therefore, the total isolation voltage of the isolation belt is required to be higher than Upd. Therefore, this high-low voltage isolation solution can only meet the high-low voltage isolation requirements of BMS below 1.5KV.

[0060] In order to improve the efficiency of energy storage and transmission and reduce the size and weight of transmission lines, the energy storage system where the BMS is located often needs to adopt a higher platform voltage. However, the higher platform voltage also puts forward new requirements for the safety and complexity of the energy storage system. The existing solutions are difficult to meet the higher high and low voltage isolation requirements.

[0061] In order to solve the above technical problems, the embodiments of the utility model provide an isolation circuit, a battery management system and a battery pack, wherein a first isolation belt and a second isolation belt connected in series are arranged between a first reference point and a second reference point where high and low voltage isolation is required. By means of the two-stage isolation belts being connected in series for voltage balancing, the isolation circuit can meet the voltage isolation requirements of the high-voltage platform, thereby improving the high and low voltage isolation capability of the isolation circuit and optimizing the reliability of the BMS.

[0062] The present invention is further described in detail below through the accompanying drawings and specific embodiments.

[0063] Figure 2 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 1 .like Figure 2 As shown, the battery management system 20 may include a processing unit 201, a sampling unit 202 and an isolation circuit 203. The isolation circuit 203 includes a first isolation zone 204 and a second isolation zone 205, wherein:

[0064] The first isolation zone 204 is set between the first reference point in the processing unit 201 and the sampling unit 202, and the second isolation zone 205 is set between the second reference point in the processing unit 201 and the sampling unit 202, for achieving high and low voltage isolation between the first reference point and the second reference point.

[0065] The sampling unit 202 is a circuit directly connected to the high voltage output by the power battery, and is a high voltage circuit; the processing unit 201 may be an MCU, and is a low voltage circuit.

[0066] It should be noted that in the embodiment of the present utility model and the following embodiments, the first reference point in the sampling unit 202 can be Figure 2 The high-voltage negative terminal shown can be connected to the negative terminal of the power battery output or the negative terminal of the high-voltage bus, and its voltage value can be equal to the voltage value of the negative terminal of the power battery output or the negative terminal of the high-voltage bus. In addition, the second reference point in the sampling unit 202 can be the ground terminal GND, and its voltage value can be 0.

[0067] In an embodiment of the utility model, the first isolation zone 204 and the second isolation zone 205 can both be devices for isolating the high-voltage circuit where the sampling unit 202 is located and the low-voltage circuit where the processing unit 201 is located, which may include an isolated power supply and an isolated communication chip, and may also include other devices that can achieve high and low voltage isolation and communication.

[0068] Therefore, one end of the first isolation zone 204 is connected to the first reference point, and the other end is connected to the processing unit 201; one end of the second isolation zone 205 is connected to the processing unit 201, and the other end is connected to the second reference point. In this way, the first isolation zone 204 and the second isolation zone 205 are connected in series between the first reference point and the second reference point. Based on the series voltage division principle, the sum of the isolation voltages that the first isolation zone 204 and the second isolation zone 205 can withstand can be used as the maximum isolation voltage that the isolation circuit 203 can meet. It can be understood that the high-low voltage isolation in the embodiment of the utility model is the isolation between the high voltage circuit, that is, the high voltage output by the power battery, and the low voltage circuit with a voltage value of 0 at the ground terminal GND.

[0069] It should be noted that the high-voltage platform can refer to a voltage that meets 1.5KV and above. As mentioned above, the current isolation zone can meet the isolation requirements of a 1.5KV high-voltage platform at most, and the first isolation zone 204 and the second isolation zone 205 have equal resistance values ​​in theory. Therefore, this series isolation scheme after the first isolation zone 204 and the second isolation zone 205 are connected in series can meet the isolation requirements of 3KV. In other words, when the voltage difference between the first reference point, i.e., the high-voltage negative terminal U00, and the second reference point, i.e., the ground terminal GND, reaches 3KV, the isolation circuit 203 provided in the embodiment of the utility model can still achieve high and low voltage isolation between the first reference point and the second reference point.

[0070] The embodiment of the utility model provides an isolation circuit, in which a first isolation belt and a second isolation belt connected in series are arranged between a first reference point and a second reference point where high and low voltage isolation is required. By means of the two-stage isolation belts being connected in series and voltage equalization, the isolation circuit can meet the voltage isolation requirements of the high-voltage platform, improves the high and low voltage isolation capability of the isolation circuit, and optimizes the reliability of the BMS.

[0071] In yet another embodiment of the present invention, Figure 3A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 2 .like Figure 3 As shown, the sampling unit includes a first sampling circuit 2021 and a second sampling circuit 2022, wherein:

[0072] The first sampling circuit 2021 is used to sample the voltage between the high voltage positive terminal and the first reference point and between the second reference point and the first reference point to determine first sampling data.

[0073] In an embodiment of the utility model, the high-voltage positive terminal, i.e., the HV+ terminal, can be connected to the positive terminal of the power battery output, or can be connected to the positive terminal of the high-voltage bus, and its voltage value is equal to the voltage value of the positive electrode of the power battery or the positive electrode of the high-voltage bus.

[0074] Wherein, the first sampling circuit 2021 can be an analog to digital converter (ADC) circuit, in which at least one voltage sampling point can be set, and the voltage sampling point can be set at a point on a device in the first sampling circuit 2021, and the voltage signal at the point is read periodically or continuously. Exemplarily, a certain sampling point can be used to sample the voltage between the high-voltage positive terminal and the first reference point to determine the voltage difference between the high-voltage positive terminal and the high-voltage negative terminal; or, another voltage sampling point can also be used to sample the voltage between the second reference point and the first reference point to determine the voltage difference between the high-voltage negative terminal and the ground terminal. It can be understood that the first sampling circuit 2021 can also set voltage sampling points at other positions in the first sampling circuit 2021 according to sampling needs.

[0075] Furthermore, the first sampling circuit 2021 may take all the voltage data collected by at least one voltage sampling point as the first sampling data, and send the data to the processing unit 201 for analysis and processing by the processing unit 201 .

[0076] The second sampling circuit 2022 is used to sample the voltage between the high voltage positive terminal and the second reference point to determine second sampling data.

[0077] In the embodiment of the utility model, the second sampling circuit 2022 may also be an ADC circuit, in which at least one voltage sampling point may be set, and the voltage sampling point may be set at a point on a device in the second sampling circuit 2022, and the voltage signal at the point may be read periodically or continuously. Exemplarily, a certain voltage sampling point may be used to sample the voltage between the high-voltage positive terminal and the second reference point, and determine the voltage difference between the high-voltage positive terminal and the ground terminal. It is understood that the second sampling circuit 2022 may also set a voltage sampling point at other positions of the second sampling circuit 2022 according to sampling needs.

[0078] Furthermore, the second sampling circuit 2022 may use all voltage data collected by at least one voltage sampling point as second sampling data, and send the data to the processing unit 201 for analysis and processing by the processing unit 201 .

[0079] It should also be noted that the sampling unit including the first sampling circuit and the second sampling circuit is only a preferred embodiment. It is understandable that the number of the first sampling circuit and the second sampling circuit is not limited to one, and it can also be two, three or more sampling circuits to achieve multi-channel high-voltage sampling. That is to say, on the basis of this embodiment, the composition structure of multiple sampling circuits added or equivalently replaced is within the protection scope of the present utility model.

[0080] In some embodiments, continue to refer to Figure 3 , the first isolation zone includes a first isolation communication unit 2042 and a first isolation power supply 2041, wherein:

[0081] The first isolated power supply 2041 is used to supply power to the first sampling circuit 2021 .

[0082] In an embodiment of the utility model, in order to prevent the first sampling circuit 2021 on the high-voltage side from being damaged due to high-voltage discharge or other reasons when the first isolated communication unit 2042 is damaged, thereby causing damage to the processing unit 201 or other circuits on the low-voltage side, the first sampling circuit 2021 and the first isolated power supply 2041 can be powered separately by the first isolated power supply 2041 to isolate the power supply of the high-voltage side from that of the low-voltage side.

[0083] The first isolated communication unit 2042 is used to receive the first sampling data sent by the first sampling circuit 2021 , and send the first sampling data to the processing unit 201 , so as to achieve isolated communication between the first sampling circuit 2021 and the processing unit 201 .

[0084] It should be noted that the first isolated communication unit 2042 may be an isolated communication chip, which can convert the first sampling data input by the first sampling circuit 2021 and output it to the processing unit 201 for processing, thereby realizing the communication between the first sampling circuit 2021 and the processing unit 201. At the same time, it can also realize the electrical isolation between the first sampling circuit 2021 on the high voltage side and the processing unit 201 on the low voltage side, thereby ensuring the security of data transmission between the first sampling circuit 2021 and the processing unit 201.

[0085] In some embodiments, continue to refer to Figure 3 , the second isolation zone includes a second isolation communication unit 2052 and a second isolation power supply 2051, wherein:

[0086] The second isolated power supply 2051 is used to supply power to the second sampling circuit 2022 .

[0087] In an embodiment of the utility model, in order to prevent the second sampling circuit 2022 on the high-voltage side from being damaged due to high-voltage discharge or other reasons when the second isolated communication unit 2052 is damaged, thereby causing damage to the processing unit 201 or other circuits on the low-voltage side, the second sampling circuit 2022 and the second isolated power supply 2051 can be powered separately by the second isolated power supply 2051 to isolate the power supply of the high-voltage side from that of the low-voltage side.

[0088] The second isolated communication unit 2052 is used to receive the second sampling data sent by the second sampling circuit 2022 and send the second sampling data to the processing unit 201 to achieve isolated communication between the second sampling circuit 2022 and the processing unit 201 .

[0089] It should be noted that the second isolated communication unit 2052 may also be an isolated communication chip, which can convert the second sampling data input by the second sampling circuit 2022 and output it to the processing unit 201 for processing, thereby realizing communication between the second sampling circuit 2022 and the processing unit 201. At the same time, it can also realize electrical isolation between the second sampling circuit 2022 on the high voltage side and the processing unit 201 on the low voltage side, thereby ensuring the security of data transmission between the second sampling circuit 2022 and the processing unit 201.

[0090] The embodiment of the utility model provides an isolation circuit, which uses a first isolation power supply and a first isolation communication unit as a first isolation zone to isolate the high and low voltage between the first sampling circuit and the processing unit; and uses a second isolation power supply and a second isolation communication unit as a second isolation zone to isolate the high and low voltage between the second sampling circuit and the processing unit. Through this two-stage series isolation method, the high and low voltage isolation capability of the isolation circuit is improved, and the reliability of the isolation circuit is optimized.

[0091] In another embodiment of the present invention, Figure 4 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 3 .like Figure 4 As shown, the isolation circuit 203 further includes a first resistor R1, wherein:

[0092] A first end of the first resistor R1 is connected to the third reference point of the processing unit 201 , and a second end of the first resistor R1 is connected to the second reference point in the sampling unit, for clamping the potential of the third reference point of the processing unit 201 .

[0093] In the embodiment of the present utility model, refer to the above Figure 3After the first isolation zone and the second isolation zone are connected in series between the first reference point and the second reference point, the first isolation zone and the second isolation zone jointly bear the voltage between the first reference point and the second reference point through the series voltage balancing effect.

[0094] Among them, the first reference point, that is, the high-voltage negative terminal is set in the first sampling circuit 2021; the second reference point, that is, the ground terminal is set in the second sampling circuit 2022. In this way, the reference ground of the processing unit 201 is in a suspended state. Since its potential is easily disturbed, it may cause problems such as resetting the processing unit 201 and interrupting communication. In addition, in the strong electric field environment of the energy storage power station, the suspension point where the processing unit 201 is located will form local discharge due to the continuous accumulation of charge. In addition, due to the aging of the PCB material, foreign matter and other reasons, the molecular structure of the insulating material of the isolation belt may be destroyed and the insulation strength may be reduced. Therefore, it is necessary to solve the problem of charge accumulation in the processing unit 201.

[0095] In the embodiment of the present utility model, in order to solve the problem of discharge caused by charge accumulation in the processing unit 201, as Figure 4 As shown, a first resistor R1 connected in parallel with the second isolation zone can be set, the first end of the first resistor R1 is connected to the third reference point of the processing unit 201, and the second end of the first resistor R1 is connected to the second reference point of the second sampling circuit 2022. Through the large resistance grounding technology, a large resistance is connected in series between the third reference point and the second reference point of the processing unit 201 to achieve the effect of clamping the potential of the third reference point of the processing unit 201.

[0096] Among them, the third reference point can be the reference ground terminal of the processing unit 201. As mentioned above, the second reference point can be the ground terminal. Therefore, after the third reference point is connected to the second reference point through the first resistor R1, the charge accumulated in the processing unit 201 can be introduced into the ground terminal through the first resistor R1.

[0097] It should be noted that the resistance value of the first resistor R1 is generally relatively large, and illustratively, may be in the kilo-ohm or mega-ohm range.

[0098] The embodiment of the utility model provides an isolation circuit, which, by setting a first resistor, extracts the accumulated charge on the processing unit, thereby solving the risk of insulation failure caused by local discharge of the processing unit in the above-mentioned two-stage series isolation high and low voltage isolation scheme, and improving the safety and stability of the isolation circuit.

[0099] In yet another embodiment of the present invention, Figure 5 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 4 .like Figure 5As shown, the isolation circuit 203 further includes a second resistor R2, wherein: a first end of the second resistor R2 is connected to the third reference point of the processing unit 201, and a second end of the second resistor R2 is connected to the first reference point in the sampling unit.

[0100] In the embodiment of the present invention, the second resistor R2 cooperates with the first resistor R1 to control the voltage balance between the first isolation zone and the second isolation zone.

[0101] It should be noted that after the first resistor R1 is set between the third reference point of the processing unit 201 and the second reference point of the second sampling circuit 2022, since the equivalent impedance of the first isolation zone is equal to that of the second isolation zone in theory, the addition of the first resistor R1 and the difference in device parameters on the first isolation zone and the second isolation zone make the equivalent impedance of the first isolation zone and the second isolation zone different. According to the voltage division principle, this may cause the voltage borne by the first isolation zone and the second isolation zone to be uneven. In the case of such voltage unevenness, when the platform voltage Upd, that is, the circuit voltage on the high-voltage side is close to the sum of the isolation voltages that the first isolation zone and the second isolation zone can withstand, the isolation zone with a lower equivalent impedance may be at risk of damage. Therefore, in order to solve the problem of uneven voltage, the first resistor R1 and the second resistor R2 are introduced here, and the voltage unevenness caused by the first isolation zone and the second isolation zone can be solved by controlling the resistance values ​​of the first resistor R1 and the second resistor R2.

[0102] That is to say, in the embodiment of the utility model, on the basis of connecting the first resistor R1 in parallel at both ends of the second isolation zone, the second resistor R2 can be connected in parallel at both ends of the first isolation zone. That is, by connecting the first resistor R1 and the second resistor R2 of tens of megahertz in parallel in the first isolation zone and the second isolation zone respectively, the voltage equalization of the first isolation zone and the second isolation zone can be achieved.

[0103] It should be noted that, in theory, the voltages at both ends of the first isolation zone and the second isolation zone are equal, so the resistance values ​​of the first resistor R1 and the second resistor R2 can be set to be equal. However, in practical applications, due to the difference in device parameters in the first isolation communication unit 2042 and the second isolation communication unit 2052, the actual impedances of the first isolation zone and the second isolation zone may not be equal. At this time, the first resistor R1 and the second resistor R2 are introduced, and by coordinating and controlling the resistance values ​​of the two resistors, the equivalent impedances of the first isolation zone and the second isolation zone can be equalized, that is, the voltages of the first isolation zone and the second isolation zone are equalized.

[0104] It should also be noted that, under normal circumstances, the sum of the equivalent impedances of the first isolation zone and the second isolation zone is greater than 1000MΩ. Therefore, in order to ensure the voltage balancing effect, the first resistor R1 and the second resistor R2 need to meet certain accuracy requirements, which can be 0.5% or 0.1% by way of example. It can be understood that when the actual impedances of the first isolation zone and the second isolation zone are close, the accuracy requirements of the resistors can be higher; when the actual impedances of the first isolation zone and the second isolation zone are far apart, the accuracy requirements of the resistors can be lower.

[0105] The embodiment of the utility model provides an isolation circuit. By setting a second resistor to cooperate with the first resistor, the equivalent impedance of the first isolation zone and the second isolation zone are made equal, thereby avoiding damage to the isolation zone due to uneven voltage division, solving the system reliability problem caused by uneven voltage division, and improving the safety and stability of the circuit.

[0106] In another embodiment of the present invention, continue to refer to Figure 5 , the first sampling circuit 2021 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, and the second sampling circuit 2022 includes a seventh resistor R7 and an eighth resistor R8, wherein:

[0107] The first end of the third resistor R3 is connected to the high voltage positive terminal, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4, the first end of the fifth resistor R5 is connected to the second reference point, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, and the second end of the fourth resistor R4 and the second end of the sixth resistor R6 are connected to the first reference point.

[0108] A first end of the seventh resistor R7 is connected to the second reference point, a second end of the seventh resistor R7 is connected to a first end of the eighth resistor R8, and a second end of the eighth resistor R8 is connected to the high voltage positive terminal.

[0109] In an embodiment of the utility model, the third resistor R3 and the fourth resistor R4 are arranged between the high voltage positive terminal and the first reference point, that is, the high voltage negative terminal; the fifth resistor R5 and the sixth resistor R6 are arranged between the first reference point and the second reference point, that is, between the high voltage negative terminal and the ground terminal.

[0110] In some embodiments, Figure 5 As shown, a first voltage sampling point V1 is provided between the second end of the third resistor R3 and the first end of the fourth resistor R4 for sampling the voltage between the high voltage positive terminal and the first reference point.

[0111] Among them, a first voltage sampling point V1 can be set at a point between the third resistor R3 and the fourth resistor R4, so that the voltage output from the high-voltage positive terminal is divided by the third resistor R3, and the divided voltage signal is periodically or continuously collected through the first voltage sampling point V1.

[0112] Further, the voltage value between the high voltage positive terminal and the first reference point may be determined according to the resistance value of the third resistor R3, the resistance value of the fourth resistor R4, and the voltage value of the first voltage sampling point V1.

[0113] A second voltage sampling point V2 is provided between the second end of the fifth resistor R5 and the first end of the sixth resistor R6 for sampling the voltage between the second reference point and the first reference point.

[0114] Among them, a second voltage sampling point V2 can be set at a point between the fifth resistor R5 and the sixth resistor R6, so that the voltage output from the high-voltage negative terminal is divided by the sixth resistor R6, and the divided voltage signal is periodically or continuously collected through the second voltage sampling point V2.

[0115] Furthermore, the voltage value between the first reference point and the second reference point, ie, between the high voltage negative terminal and the ground terminal, can be determined according to the resistance value of the fifth resistor R5, the resistance value of the sixth resistor R6, and the voltage value of the second voltage sampling point V2.

[0116] A third voltage sampling point V3 is provided between the second end of the seventh resistor R7 and the first end of the eighth resistor R8 for sampling the voltage between the high voltage positive terminal and the second reference point.

[0117] In the embodiment of the present utility model, the seventh resistor R7 and the eighth resistor R8 can be arranged between the high voltage positive terminal and the second reference point, ie, the ground terminal.

[0118] Among them, a third voltage sampling point V3 can be set at a point between the seventh resistor R7 and the eighth resistor R8, so that the voltage output from the high-voltage positive terminal is divided by the eighth resistor R8, and the divided voltage signal is periodically or continuously collected through the third voltage sampling point V3.

[0119] Further, the voltage value between the high voltage positive terminal and the second reference point, ie, the ground terminal, can be determined according to the resistance value of the seventh resistor R7, the resistance value of the eighth resistor R8, and the voltage value of the third voltage sampling point V3.

[0120] In some embodiments, Figure 6 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 5 .like Figure 6As shown, the first sampling circuit 2021 includes a fifth resistor R5, a sixth resistor R6 and a ninth resistor R9, and the second sampling circuit 2022 includes a seventh resistor R7 and an eighth resistor R8, wherein: a first end of the ninth resistor R9 is connected to the high-voltage positive terminal, a first end of the fifth resistor R5 is connected to the second reference point, a second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, a second end of the ninth resistor R9 and a second end of the sixth resistor R6 are connected to the first reference point; a first end of the seventh resistor R7 is connected to the second reference point, a second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8, and a second end of the eighth resistor R8 is connected to the high-voltage positive terminal.

[0121] The ninth resistor R9 may be an equivalent resistor of the third resistor R3 and the fourth resistor R4.

[0122] In some embodiments, continue to refer to Figure 6 A second voltage sampling point is set between the second end of the fifth resistor R5 and the first end of the sixth resistor R6, for sampling the voltage between the second reference point and the first reference point; a third voltage sampling point is set between the second end of the seventh resistor R7 and the first end of the eighth resistor R8, for sampling the voltage between the high voltage positive terminal and the second reference point.

[0123] In the embodiment of the utility model, after the voltage outputted from the high-voltage negative terminal is divided by the sixth resistor R6, the divided voltage signal is periodically or continuously collected through the second voltage sampling point V2. After the voltage outputted from the high-voltage positive terminal is divided by the eighth resistor R8, the divided voltage signal is periodically or continuously collected through the third voltage sampling point V3.

[0124] In some embodiments, Figure 7 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 6 .like Figure 7 As shown, the first sampling circuit 2021 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, and the second sampling circuit 2022 includes a tenth resistor R10, wherein: a first end of the third resistor R3 is connected to the high-voltage positive terminal, a second end of the third resistor R3 is connected to the first end of the fourth resistor R4, a first end of the fifth resistor R5 is connected to the second reference point, a second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, and a second end of the fourth resistor R4 and a second end of the sixth resistor R6 are connected to the first reference point; a first end of the tenth resistor R10 is connected to the second reference point, and a second end of the tenth resistor R10 is connected to the high-voltage positive terminal.

[0125] The tenth resistor R10 may be an equivalent resistor of the seventh resistor R7 and the eighth resistor R8.

[0126] In some embodiments, continue to refer to Figure 7 A first voltage sampling point is set between the second end of the third resistor R3 and the first end of the fourth resistor R4, for sampling the voltage between the high voltage positive terminal and the first reference point; a second voltage sampling point is set between the second end of the fifth resistor R5 and the first end of the sixth resistor R6, for sampling the voltage between the second reference point and the first reference point.

[0127] Based on the above embodiments, it can be understood that multiple sampling points can be set in the first sampling circuit 2021 and the second sampling circuit 2022. The positions of the specific sampling points can refer to the setting scheme in the above embodiments and be specifically set according to actual needs. No limitation is made here.

[0128] In some embodiments, continue to refer to Figure 5 , the sampling unit 202 also includes a first equivalent resistor Rp and a second equivalent resistor Rn, wherein:

[0129] The first equivalent resistance Rp is the equivalent impedance between the high voltage positive terminal and the second reference point, and the second equivalent resistance Rn is the equivalent impedance between the first reference point and the second reference point.

[0130] The first equivalent resistance Rp and the second equivalent resistance Rn are jointly determined according to the sampling voltages of the first voltage sampling point V1 , the second voltage sampling point V2 , and the third voltage sampling point V3 .

[0131] In the embodiment of the utility model, the first equivalent resistor Rp is a plurality of series resistors between the high voltage positive terminal and the second reference point, including the equivalent resistance of the seventh resistor R7 and the eighth resistor R8, which can be calculated and determined according to the equivalent series-parallel formula based on the resistance values ​​of the seventh resistor R7 and the eighth resistor R8. Correspondingly, the second equivalent resistor Rn is a plurality of series resistors between the first reference point and the second reference point, including the equivalent resistance of the fifth resistor R5 and the sixth resistor R6, which can be calculated and determined according to the equivalent series-parallel formula based on the resistance values ​​of the fifth resistor R5 and the sixth resistor R6.

[0132] Among them, in the processing unit 201, after receiving the voltage value of the first voltage sampling point V1, the voltage value of the second voltage sampling point V2 and the voltage value of the third voltage sampling point V3, the processing unit can determine the resistance value of the first equivalent resistor Rp and the resistance value of the second equivalent resistor Rn by calculation according to the received voltage values ​​of the three voltage sampling points.

[0133] The embodiment of the utility model provides an isolation circuit, which sets multiple resistors between the high voltage positive terminal, the first reference point, and the second reference point, and sets multiple voltage sampling points between the resistors to determine the voltage values ​​of any two of the three points, and then determines the resistance value of the first equivalent resistor and the resistance value of the second equivalent resistor according to the voltage values ​​collected by the multiple voltage sampling points. It is convenient for operators to grasp the voltage sampling situation of the sampling unit, and facilitate further insulation detection and calculation and analysis of equivalent impedance.

[0134] In another embodiment of the present invention, Figure 8 A schematic diagram of the structure of a battery management system provided in an embodiment of the utility model Figure 7 .like Figure 8 As shown, the battery management system 20 includes a processing unit 201 , a sampling unit 202 and the aforementioned isolation circuit 203 , wherein the isolation circuit 203 is connected between the processing unit 201 and the sampling unit 202 .

[0135] As mentioned above, a high voltage positive terminal HV+ and a high voltage negative terminal U00 are provided in the isolation circuit 20. The first equivalent resistance Rp is the equivalent resistance of the high voltage positive terminal to the ground terminal, and the second equivalent resistance Rn is the equivalent resistance of the high voltage negative terminal to the ground terminal.

[0136] In the embodiment of the utility model, the first sampling circuit and the second sampling circuit are both ADC circuits, which are powered by the first isolated power supply and the second isolated power supply respectively, and the first sampling data and the second sampling data are sent to the processing unit through the first isolated communication unit and the second isolated communication unit. Among them, the first voltage sampling point V1 in the isolation circuit 203 can realize high-voltage sampling, and the first voltage sampling point V1, the second voltage sampling point V2, and the third voltage sampling point V3 can cooperate to realize insulation detection to determine the resistance values ​​of the first equivalent resistor Rp and the second equivalent resistor Rn.

[0137] It should be noted that after the second reference point is set in the second sampling circuit, the third reference point of the processing unit, i.e., the reference ground, is in a suspended state, and its potential is susceptible to interference, which may cause problems such as resetting the processing unit and interrupting communication. In addition, in the strong electric field environment of the energy storage power station, the charge accumulation at the suspension point will form local discharge, destroy the molecular structure of the insulating material, and cause the insulation strength to decrease. Figure 8 As shown, through the large resistance grounding technology, a first resistor R1 with a large resistance is connected in series between the reference ground of the processing unit and the ground terminal to clamp the potential of the reference ground of the processing unit.

[0138] It should also be noted that due to differences in device parameters, there are differences in the equivalent impedances of the first isolation zone and the second isolation zone. According to the voltage division principle, the voltages borne by the first isolation zone and the second isolation zone are uneven. When the platform voltage Upd, that is, the voltage of the first reference point, is close to the sum of the isolation voltages of the first isolation zone and the second isolation zone, the isolation zone with a lower equivalent impedance is at risk of damage. Under normal circumstances, the sum of the equivalent impedances of the first isolation zone and the second isolation zone is greater than 1000MΩ. Therefore, by connecting tens of mega resistors in parallel to the first isolation zone and the second isolation zone, exemplarily including the first resistor R1 and the second resistor R2, voltage equalization of the isolation zone can be achieved. Among them, in order to ensure the voltage equalization effect, the first resistor R1 and the second resistor R2 need to meet certain accuracy requirements.

[0139] The embodiment of the utility model provides a battery management system, which improves the voltage isolation capability of the isolation circuit and optimizes the reliability of the battery management system by means of a method of connecting two-stage isolation belts in series for voltage balancing.

[0140] In another embodiment of the present invention, Fig. 9 A schematic diagram of the structure of a battery pack provided by an embodiment of the utility model. Fig. 9 As shown, the battery pack 30 may include a battery 301 and a battery management system 20 as described in any one of the aforementioned embodiments; wherein the battery 301 is connected between a high-voltage positive terminal and a high-voltage negative terminal (ie, the aforementioned "first reference point").

[0141] In the embodiment of the utility model, the positive output terminal of the battery 301 is connected to the high-voltage positive terminal of the battery management system 20, and the negative output terminal of the battery 301 is connected to the high-voltage negative terminal of the battery management system 20, which is used to output the high-voltage voltage to the high-voltage side of the battery management system 20 for sampling, and the sampled data obtained by sampling is analyzed and processed in the processing unit. Among them, the processing unit and the sampling circuit are isolated by the first isolation belt and the second isolation belt.

[0142] The embodiment of the utility model provides a battery pack that can meet the high and low voltage isolation requirements of batteries with output voltages ranging from 1.5KV to 3.0KV, thereby ensuring that the battery pack can still operate normally and reliably at a higher voltage.

[0143] It should be understood that "one embodiment" or "an embodiment" or "some embodiments" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the utility model. Therefore, "in one embodiment" or "in one embodiment" or "in some embodiments" appearing throughout the specification may not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the utility model, the size of the sequence number of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the utility model. The above-mentioned sequence numbers of the embodiments of the utility model are for description only and do not represent the advantages and disadvantages of the embodiments. The above description of each embodiment tends to emphasize the differences between the embodiments, and the same or similar aspects can be referenced to each other. For the sake of brevity, this article will not repeat them.

[0144] It should also be noted that, in the present invention, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0145] The serial numbers of the above-mentioned embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments.

[0146] The methods disclosed in the several method embodiments provided by the present invention can be arbitrarily combined without conflict to obtain new method embodiments.

[0147] The features disclosed in several product embodiments provided by the present invention can be arbitrarily combined without conflict to obtain new product embodiments.

[0148] The features disclosed in several method or device embodiments provided by the present invention can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0149] The above description is only a preferred embodiment of the present utility model and is not intended to limit the protection scope of the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.

Claims

1. An isolation circuit, characterized in that: The isolation circuit comprises a first isolation zone and a second isolation zone, wherein: The first isolation zone is arranged between the processing unit and the first reference point in the sampling unit, and the second isolation zone is arranged between the processing unit and the second reference point in the sampling unit, for realizing high and low voltage isolation between the first reference point and the second reference point; The sampling unit comprises a first sampling circuit and a second sampling circuit, wherein: The first sampling circuit is used to sample the voltage between the high voltage positive terminal and the first reference point and between the second reference point and the first reference point to determine first sampling data; The second sampling circuit is used to sample the voltage between the high-voltage positive terminal and the second reference point to determine second sampling data.

2. The isolation circuit according to claim 1, characterized in that: The first isolation zone includes a first isolation communication unit and a first isolation power supply, wherein: The first isolated power supply is used to supply power to the first sampling circuit; The first isolated communication unit is used to receive the first sampling data sent by the first sampling circuit, and send the first sampling data to the processing unit to achieve isolated communication between the first sampling circuit and the processing unit.

3. The isolation circuit according to claim 1, characterized in that: The second isolation zone includes a second isolation communication unit and a second isolation power supply, wherein: The second isolated power supply is used to supply power to the second sampling circuit; The second isolated communication unit is used to receive the second sampling data sent by the second sampling circuit, and send the second sampling data to the processing unit to achieve isolated communication between the second sampling circuit and the processing unit.

4. The isolation circuit according to claim 1, characterized in that: The isolation circuit further comprises a first resistor, wherein: The first end of the first resistor is connected to the third reference point of the processing unit, and the second end of the first resistor is connected to the second reference point in the sampling unit, for clamping the potential of the third reference point of the processing unit.

5. The isolation circuit according to claim 4, characterized in that: The isolation circuit further includes a second resistor, wherein: A first end of the second resistor is connected to a third reference point of the processing unit, and a second end of the second resistor is connected to a first reference point in the sampling unit.

6. The isolation circuit according to claim 1, characterized in that: The first sampling circuit includes a third resistor, a fourth resistor, a fifth resistor and a sixth resistor, and the second sampling circuit includes a seventh resistor and an eighth resistor, wherein: The first end of the third resistor is connected to the high voltage positive terminal, the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the fifth resistor is connected to the second reference point, the second end of the fifth resistor is connected to the first end of the sixth resistor, and the second end of the fourth resistor and the second end of the sixth resistor are connected to the first reference point; The first end of the seventh resistor is connected to the second reference point, the second end of the seventh resistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the high voltage positive terminal.

7. The isolation circuit according to claim 6, characterized in that: A first voltage sampling point is provided between the second end of the third resistor and the first end of the fourth resistor, for sampling the voltage between the high voltage positive terminal and the first reference point; A second voltage sampling point is provided between the second end of the fifth resistor and the first end of the sixth resistor, for sampling the voltage between the second reference point and the first reference point; A third voltage sampling point is provided between the second end of the seventh resistor and the first end of the eighth resistor for sampling the voltage between the high voltage positive terminal and the second reference point.

8. The isolation circuit according to claim 1, characterized in that: The first sampling circuit includes a fifth resistor, a sixth resistor and a ninth resistor, and the second sampling circuit includes a seventh resistor and an eighth resistor, wherein: The first end of the ninth resistor is connected to the high voltage positive terminal, the first end of the fifth resistor is connected to the second reference point, the second end of the fifth resistor is connected to the first end of the sixth resistor, and the second end of the ninth resistor and the second end of the sixth resistor are connected to the first reference point; The first end of the seventh resistor is connected to the second reference point, the second end of the seventh resistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the high voltage positive terminal.

9. The isolation circuit according to claim 8, characterized in that: A second voltage sampling point is provided between the second end of the fifth resistor and the first end of the sixth resistor, for sampling the voltage between the second reference point and the first reference point; A third voltage sampling point is provided between the second end of the seventh resistor and the first end of the eighth resistor for sampling the voltage between the high voltage positive terminal and the second reference point.

10. The isolation circuit according to claim 1, characterized in that: The first sampling circuit includes a third resistor, a fourth resistor, a fifth resistor and a sixth resistor, and the second sampling circuit includes a tenth resistor, wherein: The first end of the third resistor is connected to the high voltage positive terminal, the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the fifth resistor is connected to the second reference point, the second end of the fifth resistor is connected to the first end of the sixth resistor, and the second end of the fourth resistor and the second end of the sixth resistor are connected to the first reference point; The first end of the tenth resistor is connected to the second reference point, and the second end of the tenth resistor is connected to the high voltage positive terminal.

11. The isolation circuit according to claim 10, characterized in that: A first voltage sampling point is provided between the second end of the third resistor and the first end of the fourth resistor, for sampling the voltage between the high voltage positive terminal and the first reference point; A second voltage sampling point is provided between the second end of the fifth resistor and the first end of the sixth resistor, for sampling the voltage between the second reference point and the first reference point.

12. The isolation circuit according to claim 7, characterized in that: The sampling unit further includes a first equivalent resistor and a second equivalent resistor, wherein: The first equivalent resistance is the equivalent impedance between the high voltage positive terminal and the second reference point, and the second equivalent resistance is the equivalent impedance between the first reference point and the second reference point; The first equivalent resistance and the second equivalent resistance are jointly determined according to the sampling voltages of the first voltage sampling point, the second voltage sampling point and the third voltage sampling point.

13. A battery management system, characterized in that: The battery management system comprises a processing unit, a sampling unit and an isolation circuit according to any one of claims 1 to 12, wherein: The isolation circuit is connected between the processing unit and the sampling unit.

14. A battery pack, characterized in that: The battery pack includes a battery and a battery management system as claimed in claim 13; wherein the battery is connected between a high voltage positive terminal and a first reference point.

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