Fault detection method and device for optical coupling switch in battery detection system

Abstract

The present invention provides a fault detection method and device for an optical coupling switch in a battery detection system, including constructing an equivalent circuit model of a battery detection system according to the battery detection system; obtaining the total voltage and module voltage of the equivalent circuit modules of all optical coupling switches in the equivalent circuit model of the battery detection system under various switch combination states; obtaining the voltage ratio of the equivalent circuit model of all optical coupling switches under various switch combination states according to the total voltage and module voltage of the equivalent circuit modules under the same switch combination state; constructing a switch attribute combination relationship table of the voltage ratio of the equivalent circuit model of all optical coupling switches under various switch attribute state combinations and all optical coupling switches; and realizing the detection of all optical coupling switch faults in the battery detection system according to the switch attribute combination relationship table and the voltage ratio under all switch combination states. The present invention can accurately determine whether all optical coupling switches are faulty while reducing the detection cost.

Description

Technical Field

[0001] The invention relates to detection technology, and in particular to a method and device for detecting a fault of an optical coupling switch in a battery detection system. Background Art

[0002] In the field of power detection, it is usually necessary to determine the status of various switches (such as optocouplers, circuit breakers, etc.) to ensure the safe and stable operation of the application system. For example, if the abnormal closing and opening of the circuit breaker cannot be discovered in time, the circuit breaker will be used with a defect or performance degradation, or if the circuit breaker is not maintained and replaced in time, and the circuit breaker is not repaired or replaced until it is completely inoperable or the circuit breaker fails, it will inevitably cause power interruption during the maintenance and replacement of the circuit breaker, and even the circuit breaker performance degradation during the short-circuit current interruption, resulting in the expansion of the fault caused by protection failure, causing greater economic losses.

[0003] For the power system currently using switches, in order to detect the various open and closed states in the system, it is necessary to add additional open and closed state detection devices. For example, the open and closed state detection device includes a detection circuit and a judgment circuit. Generally, an optical coupler can be used to isolate the switch to be detected from the detection circuit. Specifically, a resistor is required to be connected in series with the switch to be tested for detection, and the series resistor will generate large power consumption; or the detection circuit includes a structure composed of other electronic components such as an inductor coil, which has a complex structure and high cost.

[0004] Therefore, the problem of complex electrical connection and high cost of using additional detection devices in the current state detection process needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a method and device for detecting faults of an optical coupling switch in a battery detection system, so as to solve the problem of complex electrical connection structure and high cost of using an additional detection device in the prior art.

[0006] To achieve the above-mentioned object and other related objects, the present invention provides a method for detecting a fault of an optical coupling switch in a battery detection system, the method comprising at least the following steps:

[0007] An equivalent circuit model of the battery detection system is constructed according to the battery detection system; the battery detection system includes M optical coupling switches and N battery packs; and when the opening and closing states of all optical coupling switches are normal, the disconnection of any optical coupling switch can form a loop of the battery detection system; wherein N is greater than M, and M≥2;

[0008] According to the battery detection system, the total voltage of the equivalent circuit module of all optical coupling switches in the equivalent circuit model of the battery detection system in various open and close combination states and the module voltage of the equivalent circuit model are obtained;

[0009] The voltage ratio of the equivalent circuit model of all optical coupling switches in the battery detection system under various switch combination states is obtained according to the total voltage of the equivalent circuit module under the same switch combination state and the module voltage of the equivalent circuit model;

[0010] Constructing a switch attribute combination relationship table of the voltage ratio of the equivalent circuit model of all optical coupling switches in various on-off combination states and all optical coupling switches in various switch attribute state combinations;

[0011] All optical coupling switch faults in the battery detection system are detected according to the switch attribute combination relationship table and the voltage ratios under all switch combination states.

[0012] Preferably, the equivalent circuit model of the battery detection system includes at least two parallel modules, which are connected in series; each of the parallel modules includes a switch branch and a resistance branch; the switch branch includes a resistor and an optical coupling switch, and the resistance branch includes at least one resistor.

[0013] Preferably, the open and closed combination states include three types;

[0014] The first switch combination state is that the first switch is open and the second switch is open;

[0015] The second switch combination state is that the first switch is closed and the second switch is open;

[0016] The third switch combination state is that the first switch is open and the second switch is closed.

[0017] Preferably, the total voltage of the equivalent circuit model is the terminal voltage of the equivalent circuit model.

[0018] Preferably, the module voltage of the equivalent circuit model is the terminal voltage of at least one parallel module; wherein the module voltage is smaller than the total voltage.

[0019] Preferably, the voltage ratio of the equivalent circuit model is a ratio of a module voltage of the equivalent circuit model to a total voltage of the equivalent circuit model.

[0020] Preferably, the switch attribute states of each optical coupling switch include normal, short circuit, open circuit and half conduction.

[0021] Preferably, the process of constructing the switch attribute combination relationship table includes:

[0022] Preset a set number of voltage ratio ranges of equivalent circuit models; and number each voltage ratio range;

[0023] Based on the voltage ratio range and number of each switch combination state, the combination number in all switch combination states is obtained;

[0024] The switch attribute combination relationship table is obtained according to the combination numbers of all the switch combination states and all the switch attribute state combinations of all the optical coupling switches.

[0025] Preferably, the process of detecting all optical coupling switch faults in the battery detection system based on the voltage ratios in all switch combination states based on the switch attribute combination relationship table includes:

[0026] Compare the voltage ratios of all the switch combination states in the battery detection system with the voltage ratio ranges of each switch combination state corresponding to the combination numbers of all the switch combination states in the switch attribute combination relationship table to obtain the combination numbers of all the switch combination states in the battery detection system;

[0027] Obtaining the switch attribute states of all optical coupling switches in the battery detection system according to the combination numbers of all the open and close combination states in the switch attribute combination relationship table of the battery detection system;

[0028] Through the switch attribute states of all optical coupling switches, it is possible to accurately detect and judge whether all optical coupling switches of the battery detection system are faulty.

[0029] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a fault detection device for an optical coupling switch in a battery detection system, the device comprising a processor and a memory, the memory storing a computer program that can be run on the processor, and the computer program, when executed by the processor, implements the steps of the above-mentioned fault detection method for an optical coupling switch in a battery detection system.

[0030] As described above, the optical coupling switch fault detection method and device in the battery detection system of the present invention have the following beneficial effects:

[0031] The present invention constructs an equivalent circuit model of a battery detection system according to a battery detection system; obtains the total voltage and module voltage of the equivalent circuit module of all optical coupling switches in the equivalent circuit model of the battery detection system under various switch combination states; obtains the voltage ratio of the equivalent circuit model of all optical coupling switches under various switch combination states according to the total voltage and module voltage of the equivalent circuit module under the same switch combination state; and detects the faults of all optical coupling switches in the battery detection system according to the pre-constructed switch attribute combination relationship table and the voltage ratio under all switch combination states. The present invention only needs to rely on the original battery detection system to obtain the total voltage of the equivalent circuit model and the module voltage of at least one parallel module, and does not need to add additional circuits, which greatly reduces the cost of fault detection; and the voltage ratio of all optical coupling switches under various switch combination states is calculated by a software method, and based on the pre-constructed voltage ratio under all switch combination states and the switch switch fault relationship table, the fault conditions of all optical coupling switches in the battery detection system can be accurately detected and judged. Therefore, the present invention can accurately judge whether all optical coupling switches are faulty while reducing the detection cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic flow chart of a method for detecting a fault of an optical coupling switch in a battery detection system of the present invention.

[0033] Figure 2 Shown is a structural schematic diagram of an equivalent circuit model of a battery detection system in an embodiment of the present invention.

[0034] Figure 3 Shown is a structural schematic diagram of a fault detection device for an optical coupling switch in a battery detection system of the present invention. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] See also Figure 1-3 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0037] In the present invention, the switch application system is based on that: some relevant information will be detected before the battery leaves the factory. Generally, some electrical parameters of the battery are obtained by controlling and changing the opening and closing states of different switches in the battery detection system, and the electrical parameters are processed to determine whether the battery meets the relevant factory requirements. In order to ensure the reliability of the battery detection system, the battery detection system needs to diagnose the opening and closing states of each switch in the battery system. Only when the opening and closing states of all optical coupling switches are normal can the reliability of the output results of the battery detection system be guaranteed. Therefore, the present invention proposes a fault detection method and device for optical coupling switches in a battery detection system.

[0038] Method Example:

[0039] The flow chart of the fault detection method of the optical coupling switch in the battery detection system is as follows: Figure 1 As shown, the following combination Figure 1 The steps of the optical coupling switch fault detection method in the battery detection system of the present invention are described in detail. The method at least includes:

[0040] S1, constructing an equivalent circuit model of the battery detection system according to the battery detection system; the battery detection system includes M optical coupling switches and N battery packs; and when the opening and closing states of all optical coupling switches are normal, the disconnection of any optical coupling switch can form a loop for the battery detection system; wherein N is greater than M, and M≥2.

[0041] The on / off state of the present invention includes closed and open. The present invention treats the battery pack as equivalent to a resistor, and obtains an equivalent circuit model of the battery detection system based on the electrical connection relationship between the switch and the battery pack.

[0042] The equivalent circuit model of the battery detection system of the present invention includes at least two parallel modules, which are connected in series; each of the parallel modules includes a switch branch and a resistance branch; the switch branch includes a resistor and an optical coupling switch, and the resistance branch includes at least one resistor.

[0043] In the embodiment of the present invention, the equivalent circuit model of the battery detection system is as follows: Figure 2 As shown, it includes two parallel modules, which are connected in series; each parallel module includes a switch branch and a resistor branch; and each switch branch includes a resistor and an optical coupling switch, and each resistor branch includes a resistor.

[0044] In order to facilitate the subsequent clear description of each switch and resistor in the equivalent circuit model of the battery detection system, each parallel module, each switch and each resistor are defined.

[0045] The equivalent circuit model of the battery detection system includes a first parallel module and a second parallel module; one end of the first parallel module is used to connect to the positive pole of the power supply, the other end of the first parallel module is connected to one end of the second parallel module, and the other end of the second parallel module is used to connect to the negative pole of the power supply;

[0046] The first parallel module includes a first switch branch and a first resistor branch; the first switch branch includes a first resistor R1 and a first optical coupling switch S+; the first resistor branch includes a third resistor R3; the parallel resistance of the first parallel module is R13;

[0047] The second parallel module includes a second switch branch and a second resistor branch; the second switch branch includes a second resistor R2 and an optically coupled second switch S-; the second resistor branch includes a fourth resistor R4, and the parallel resistance of the second parallel module is R24.

[0048] S2, obtaining, according to the battery detection system, the total voltage of the equivalent circuit modules of all optical coupling switches in the equivalent circuit model of the battery detection system in various open and close combination states and the module voltage of the equivalent circuit model;

[0049] The open and closed combination states include three types;

[0050] The first switch combination state is that the first switch is open and the second switch is open;

[0051] The second switch combination state is that the first switch is closed and the second switch is open;

[0052] The third switch combination state is that the first switch is open and the second switch is closed.

[0053] S21, obtaining the total voltage of the equivalent circuit model of all optical coupling switches in the equivalent circuit model of the battery detection system in various open and close combination states; the total voltage of the equivalent circuit model is the terminal voltage of the equivalent circuit model;

[0054] In the embodiment of the present invention, Figure 2 As shown, the total voltage of the equivalent circuit model is the terminal voltage U after the first parallel module and the second parallel module are connected in series; then the total voltage of the equivalent circuit model under different switch combination states is:

[0055] The first total voltage corresponding to the first switch combination state is U1;

[0056] The second total voltage corresponding to the second opening and closing combination state is U2;

[0057] The third total voltage corresponding to the third switch combination state is U3.

[0058] S22, obtaining the module voltage of the equivalent circuit model of all optical coupling switches in the equivalent circuit model of the battery detection system in various open and closed combination states; the module voltage of the equivalent circuit model is the terminal voltage of at least one parallel module; wherein the module voltage is less than the total voltage;

[0059] In the embodiment of the present invention, Figure 2 As shown, the module voltage of the equivalent circuit model is the terminal voltage V of the second parallel module; then the module voltages of the equivalent circuit model under different switch combination states are:

[0060] The first module voltage corresponding to the first opening and closing combination state is V1;

[0061] The second module voltage corresponding to the second opening and closing combination state is V2;

[0062] The third module voltage corresponding to the third switch combination state is V3.

[0063] S3, obtaining a voltage ratio of the equivalent circuit model of all optical coupling switches in the battery detection system under various opening and closing combination states according to the total voltage of the equivalent circuit module under the same opening and closing combination state and the module voltage of the equivalent circuit model;

[0064] The voltage ratio of the equivalent circuit model of the present invention is the ratio of the module voltage of the equivalent circuit model to the total voltage of the equivalent circuit model.

[0065] In the embodiment of the present invention, the voltage ratios of the equivalent circuit model in different switch combination states are respectively:

[0066] The first voltage ratio corresponding to the first switch combination state is K1=U1 / V1;

[0067] The second voltage ratio corresponding to the second opening and closing combination state is K2=U2 / V2;

[0068] The voltage ratio corresponding to the third switch combination state is K3=U3 / V3.

[0069] S4, constructing a switch attribute combination relationship table of the voltage ratio of the equivalent circuit model of all optical coupling switches in various on-off combination states and the switch attribute state combinations of all optical coupling switches;

[0070] The switch attribute states of each optical coupling switch in the present invention include normal, short circuit, open circuit and semi-conduction. Among them, normal means that the optical coupling switch is functional both when closed and opened, short circuit means that the optical coupling switch cannot be opened, open circuit means that the optical coupling switch cannot be closed, and semi-conduction means that the optical coupling switch can be closed but has a certain impedance.

[0071] In the embodiment of the present invention, the switch attribute state of the first optical coupling switch in the switch attribute state includes normal, short circuit, open circuit and half conduction; the switch attribute state of the second optical coupling switch in the switch attribute state includes normal, short circuit, open circuit and half conduction; then, the various switch attribute state combinations of all optical coupling switches (i.e., the first optical coupling switch and the second optical coupling switch) include 16 kinds.

[0072] When constructing the switch attribute combination relationship table, all optical coupling switches are set to various switch attribute states, and a large number of experiments are carried out under various open and closed combination states to obtain a large amount of experimental data. The experimental data are processed to obtain the voltage ratio of the equivalent circuit model of all optical coupling switches in all open and closed combination states corresponding to different switch attribute combinations.

[0073] The switch attribute combination relationship table of the present invention is a voltage ratio of the equivalent circuit model of all optical coupling switches corresponding to each combination of optical coupling switch attribute states of all optical coupling switches in each open and closed combination state.

[0074] In an embodiment of the present invention, the switch attribute combination relationship table is specifically embodied as the first switch and the second switch simultaneously correspond to the first opening and closing combination state equivalent circuit model ratio K1, the second opening and closing combination state equivalent circuit model ratio K2 and the third opening and closing combination state equivalent circuit model ratio K3 in each switch attribute state combination.

[0075] The construction process of the switch attribute combination relationship table in the present invention includes:

[0076] S41, presetting a set number of voltage ratio ranges of the equivalent circuit model; and numbering each voltage ratio range;

[0077] In the embodiment of the present invention, 8 voltage ratio range values ​​are preset and numbered 1-8 respectively; wherein, the following 8 voltage ratio ranges are set considering that the voltage error range is 10%.

[0078] The first voltage ratio range is [90%*R4 / (R3+R4), 110%*R4 / (R3+R4)]; and it is numbered as 1;

[0079] The second voltage ratio range is [90%*R4 / (R13+R4), 110%*R4 / (R13+R4)]; and is numbered as 2;

[0080] The third voltage ratio range is [90%*R24 / (R3+R24), 110%*R24 / (R3+R24)]; and is numbered as 3;

[0081] The fourth voltage ratio range is [110%*R24 / (R3+R24), 90%*R4 / (R3+R4)]; and is numbered as 4;

[0082] The fifth voltage ratio range is [110%*R4 / (R3+R4), 90%*R4 / (R13+R4)]; and is numbered as 5;

[0083] The sixth voltage ratio range is [90%*R24 / (R13+R24), 110%*R24 / (R13+R24)]; and is numbered as 6;

[0084] The seventh voltage ratio range is [110%*R24 / (R13+R24), 90%*R4 / (R13+R4)]; and is numbered as 7;

[0085] The eighth voltage ratio range is [110%*R24 / (R3+R24), 90%*R24 / (R13+R24)] and is numbered as 8; as other implementations, the ratios of the eight voltage ratio ranges may also be other voltage error ranges (e.g., 5%, 20%, 30%, etc.), and the specific voltage ratio range is determined according to the components and system-related requirements in the actual battery detection system.

[0086] S42, obtaining the combination number in all the switch combination states based on the voltage ratio range and number of each switch combination state;

[0087] The combination number NUM of all open and closed combination states is:

[0088] NUM=A1×10 h-1 +A2×10 h-2 +…+Ah×10 0 ;

[0089] In the formula, A1 is the number corresponding to the voltage ratio range in the first switching combination state; A2 is the number corresponding to the voltage ratio range in the second switching combination state; ...; A1 is the number corresponding to the voltage ratio range in the first switching combination state; h is the number of combinations of switching combination states.

[0090] Table 1

[0091]

[0092] In an embodiment of the present invention, as shown in Table 1, the combination numbers of the opening and closing combination states under various switch attribute state combinations are shown; if the voltage ratio range of the first opening and closing combination state is numbered 1, the voltage ratio range of the second opening and closing combination state is numbered 1, and the voltage ratio range of the third opening and closing combination state is numbered 1, then the combination number of all opening and closing combination states is 111.

[0093] S43, obtaining the switch attribute combination relationship table according to the combination numbers of all the switch combination states and all the switch attribute state combinations of all the optical coupling switches.

[0094] The present invention selects the combination numbers that meet all switch attribute state combinations from the combination numbers of all switch combination states, and constructs all switch attribute state combinations and their corresponding combination numbers into a switch attribute combination relationship table.

[0095] In the embodiment of the present invention, the switch attribute combination relationship table corresponding to the 16 switch attribute state combinations is shown in Table 2.

[0096] Table 2

[0097] S+ S- NUM normal normal 123 normal Short Circuit 363 normal Circuit Breaker 121 normal Half conduction 124 Short Circuit normal 226 Short Circuit Short Circuit 666 Short Circuit Circuit Breaker 222 Short Circuit Half conduction 227 Circuit Breaker normal 113 Circuit Breaker Short Circuit 333 Circuit Breaker Circuit Breaker 111 Circuit Breaker Half conduction 114 Half conduction normal 153 Half conduction Short Circuit 383 Half conduction Circuit Breaker 151 Half conduction Half conduction 154

[0098] As another implementation manner, the switch attribute combination relationship table also includes the voltage ratio range of all switch and closing combination states corresponding to each switch attribute state combination; in an embodiment of the present invention, the switch attribute combination relationship table also includes the voltage ratio range of all switch and closing combination states corresponding to the switch attribute state combination as shown in Table 3.

[0099] Table 3

[0100]

[0101]

[0102] S5, detecting all optical coupling switch faults in the battery detection system according to the switch attribute combination relationship table and the voltage ratios under all switch combination states.

[0103] The present invention implements a process of detecting all optical coupling switch faults in a battery detection system based on the switch attribute combination relationship table for the voltage ratios in all open and closed combination states, including:

[0104] S51, comparing the voltage ratios of all the switch combination states in the battery detection system with the voltage ratio ranges of the switch combination states corresponding to the combination numbers of all the switch combination states in the switch attribute combination relationship table to obtain the combination numbers of all the switch combination states in the battery detection system;

[0105] In an embodiment of the present invention, the voltage ratios of the equivalent circuit model under different opening and closing combination states obtained by the battery detection system through the equivalent circuit model are: the first voltage ratio corresponding to the first opening and closing combination state is K1, the second voltage ratio corresponding to the second opening and closing combination state is K2, and the voltage ratio corresponding to the third opening and closing combination state is K3.

[0106] When the voltage ratio range corresponding to the first voltage ratio K1 corresponding to the first switching combination state is numbered 1, the voltage ratio range corresponding to the second voltage ratio K2 corresponding to the second switching combination state is numbered 2, and the voltage ratio range corresponding to the third voltage ratio K3 corresponding to the third switching combination state is numbered 1, then the combination number of the two optical coupling switches in the three switching combination states in the battery detection is 121.

[0107] S52, obtaining the switch attribute states of all optical coupling switches in the battery detection system according to the combination numbers of all the open and close combination states in the switch attribute combination relationship table of the battery detection system;

[0108] In an embodiment of the present invention, according to the combination number 121 of the two optical coupling switches in the three open and closed combination states in the switch attribute combination relationship table shown in Table 2 or Table 3, the switch attribute states of the two optical coupling switches are that the first optical coupling switch S+ is normal, and the second optical coupling switch S- is open.

[0109] S53, accurately detecting and judging whether all optical coupling switches of the battery detection system are faulty through the switch attribute states of all optical coupling switches.

[0110] In the embodiment of the present invention, the switch attribute states of the two optical coupling switches are that the first optical coupling switch S+ is normal and the second optical coupling switch S- is open circuit. Therefore, the detection and judgment show that during the current operation of the battery detection system, the first optical coupling switch is normal and the second optical coupling switch is abnormal, which will affect the reliability of some detection electrical parameters and related calculation results in the battery detection system.

[0111] The present invention only needs to rely on the original battery detection system to obtain the total voltage of the equivalent circuit model and the module voltage of at least one parallel module, without the need for an additional fault detection circuit, and the voltage ratio of all optical coupling switches in various open and close combination states is calculated by a software method, and finally the fault conditions of all optical coupling switches in the battery detection system can be detected and judged according to the voltage ratios in all open and close combination states and the switch open and close fault relationship table. The method does not require an additional fault detection circuit or a processing judgment circuit, and can accurately judge the fault conditions of all optical coupling switches by relying only on the voltage data in the original battery detection system and software processing.

[0112] Device Example:

[0113] The present invention also provides a fault detection device for an optical coupling switch in a battery detection system. Figure 3 As shown, the device includes a processor and a memory, the memory stores a computer program that can be run on the processor, and when the computer program is executed by the processor, the steps of the fault detection method of the optical coupling switch in the battery detection system are implemented.

[0114] Since the technical concept and steps of the fault detection method of the optical coupling switch in the battery detection system have been described in detail in the method embodiment, they will not be repeated in this embodiment.

[0115] In summary, the method and device for detecting the fault of the optical coupling switch in the battery detection system of the present invention only need to rely on the original battery detection system to obtain the total voltage of the equivalent circuit model and the module voltage of at least one parallel module, without the need for additional circuits, which greatly reduces the cost of fault detection; and the voltage ratio of all optical coupling switches in various open and close combination states is calculated by software methods, and based on the pre-constructed voltage ratios in all open and close combination states and the switch open and close fault relationship table, the fault conditions of all optical coupling switches in the battery detection system can be accurately detected and judged. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0116] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for detecting a fault of an optical coupling switch in a battery detection system, characterized in that: The method comprises at least the following steps: An equivalent circuit model of the battery detection system is constructed according to the battery detection system; the battery detection system includes M optical coupling switches and N battery packs; and when the opening and closing states of all optical coupling switches are normal, the disconnection of any optical coupling switch can form a loop of the battery detection system; wherein N is greater than M, and M≥2; According to the battery detection system, the total voltage of the equivalent circuit module of all optical coupling switches in the equivalent circuit model of the battery detection system in various open and close combination states and the module voltage of the equivalent circuit model are obtained; The voltage ratio of the equivalent circuit model of all optical coupling switches in the battery detection system under various switch combination states is obtained according to the total voltage of the equivalent circuit module under the same switch combination state and the module voltage of the equivalent circuit model; Constructing a switch attribute combination relationship table of the voltage ratio of the equivalent circuit model of all optical coupling switches in various on-off combination states and all optical coupling switches in various switch attribute state combinations; All optical coupling switch faults in the battery detection system are detected according to the switch attribute combination relationship table and the voltage ratios under all switch combination states.

2. The method for detecting a fault of an optical coupling switch in a battery detection system according to claim 1, characterized in that: The equivalent circuit model of the battery detection system includes at least two parallel modules, which are connected in series; each of the parallel modules includes a switch branch and a resistance branch; the switch branch includes a resistor and an optical coupling switch, and the resistance branch includes at least one resistor.

3. The method for detecting a fault of an optical coupling switch in a battery detection system according to claim 1, characterized in that: The open and closed combination states include three types; The first switch combination state is that the first switch is open and the second switch is open; The second switch combination state is that the first switch is closed and the second switch is open; The third switch combination state is that the first switch is open and the second switch is closed.

4. The method for detecting a fault of an optical coupling switch in a battery detection system according to claim 1, characterized in that: The total voltage of the equivalent circuit model is the terminal voltage of the equivalent circuit model.

5. The method for detecting faults of optical coupling switches in a battery detection system according to claim 1, characterized in that: The module voltage of the equivalent circuit model is the terminal voltage of at least one parallel module; wherein the module voltage is less than the total voltage.

6. The method for detecting faults of optical coupling switches in a battery detection system according to claim 1, characterized in that: The voltage ratio of the equivalent circuit model is the ratio of the module voltage of the equivalent circuit model to the total voltage of the equivalent circuit model.

7. The method for detecting faults of optical coupling switches in a battery detection system according to claim 1, characterized in that: The switch attribute states of each optical coupling switch include normal, short circuit, open circuit and half conduction.

8. The method for detecting faults of optical coupling switches in a battery detection system according to claim 1, characterized in that: The construction process of the switch attribute combination relationship table includes: Preset a set number of voltage ratio ranges of equivalent circuit models; and number each voltage ratio range; Based on the voltage ratio range and number of each switch combination state, the combination number in all switch combination states is obtained; The switch attribute combination relationship table is obtained according to the combination numbers of all the switch combination states and all the switch attribute state combinations of all the optical coupling switches.

9. The method for detecting faults of optical coupling switches in a battery detection system according to claim 1, characterized in that: The process of detecting all optical coupling switch faults in the battery detection system based on the voltage ratios in all switch combination states based on the switch attribute combination relationship table includes: Compare the voltage ratios of all the switch combination states in the battery detection system with the voltage ratio ranges of each switch combination state corresponding to the combination numbers of all the switch combination states in the switch attribute combination relationship table to obtain the combination numbers of all the switch combination states in the battery detection system; Obtaining the switch attribute states of all optical coupling switches in the battery detection system according to the combination numbers of all the open and close combination states in the switch attribute combination relationship table of the battery detection system; Through the switch attribute states of all optical coupling switches, it is possible to accurately detect and judge whether all optical coupling switches of the battery detection system are faulty.

10. A fault detection device for an optical coupling switch in a battery detection system, characterized in that: The device includes a processor and a memory, wherein the memory stores a computer program that can be run on the processor, and when the computer program is executed by the processor, the steps of the method for detecting a fault of an optical coupling switch in a battery detection system according to any one of claims 1 to 9 are implemented.

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