Open circuit detection method and circuit for withstand voltage test of industrial control system

Abstract

The present invention discloses a circuit break detection method and a circuit break detection circuit for a withstand voltage test of an industrial control system. The circuit break detection method includes: applying a preset voltage between the positive electrode and the negative electrode of the battery and judging whether the leakage current is less than a preset current threshold value, if it is less than the current threshold value, judging whether the first isolation value is greater than the isolation threshold value, if it is greater, controlling each varistor to conduct, and judging whether the second isolation is greater than the isolation threshold value, if it is greater, judging whether the third isolation and the fourth isolation are balanced, and if they are balanced, obtaining a passing test result. The above-mentioned circuit break detection method first detects the voltage difference between the positive and negative electrodes of the battery and the first isolation, and if the corresponding conditions are met, controls the varistor to conduct, further detects the second isolation and detects whether the third isolation and the fourth isolation are balanced, thereby obtaining a passing test result, which improves the accuracy of detecting whether the varistor circuit is circuit broken.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and in particular to a circuit break detection method and a circuit break detection circuit for a withstand voltage test of an industrial control system. Background Art

[0002] The PCS (Power Conversion System) system circuit board needs to be subjected to a withstand voltage test before actual application to ensure that the insulation capacity of the PCS energy storage converter circuit is qualified when high voltage is added within a certain period of time, so as to ensure that the insulation performance of the product is sufficient. The withstand voltage test is one of the tests to ensure the safety and reliability of the product.

[0003] In the circuit design of this product, a varistor must be added. When the voltage of the product circuit is damaged by overvoltage, such as under the impact of transient high voltage of lightning surge, the varistor absorbs the energy of lightning surge, thereby protecting the product circuit. When the product is subjected to a withstand voltage test, if a varistor is added to the circuit of the product, the varistor cannot withstand the high voltage of the withstand voltage test process, so it will cause the varistor to fail during the withstand voltage test. Therefore, when the product is subjected to a withstand voltage test, it is necessary to disconnect the varistor circuit of the product. However, multiple detection loops are designed for the detection of the varistor circuit. In the prior art, it is usually manually detected whether the varistor circuit is disconnected. It is easy to neglect some detection loops, resulting in inaccurate and incomplete detection results, which makes the varistor circuit present a greater risk during the detection process. Therefore, the method used for varistor circuit detection in the prior art has the problem of insufficient detection accuracy. Summary of the invention

[0004] The embodiment of the present invention provides a circuit break detection method and a circuit break detection circuit for a withstand voltage test of an industrial control system, aiming to solve the problem of insufficient detection accuracy in the methods for detecting pressure-sensitive circuits in the prior art.

[0005] In a first aspect, an embodiment of the present invention provides a circuit break detection method for a withstand voltage test of an industrial control system, wherein the circuit break detection method is applied to a controller, and the controller is electrically connected to a battery positive electrode, a battery negative electrode, a ground detection terminal and a cross-link detection terminal of a varistor circuit, a battery control terminal and each varistor; the detection method comprises:

[0006] Applying a preset voltage between the positive electrode of the battery and the negative electrode of the battery, and detecting and obtaining a leakage current between the positive electrode of the battery and the negative electrode of the battery;

[0007] Determine whether the leakage current is less than a preset current threshold value, and obtain a leakage current determination result;

[0008] If the leakage current judgment result is yes, judging whether the first isolation between the cross-link detection terminal and the ground detection terminal is greater than a preset isolation threshold;

[0009] If the first isolation is greater than the isolation threshold, issuing a corresponding conduction control instruction to each varistor in the varistor circuit to turn on each varistor;

[0010] Determining whether a second isolation degree between the cross-link detection terminal and the ground detection terminal is greater than the isolation degree threshold;

[0011] If the second isolation is greater than the isolation threshold, judging whether the third isolation and the fourth isolation are balanced according to a preset balance judgment rule, and obtaining a corresponding balance judgment result; the third isolation is the isolation between the positive electrode of the battery and the cross-linking detection end, and the fourth isolation is the isolation between the negative electrode of the battery and the cross-linking detection end;

[0012] If the balance judgment result is phase balance, a passing test result is obtained.

[0013] In the second aspect, the embodiment of the present application further provides a circuit break detection circuit for a withstand voltage test of an industrial control system, wherein the circuit break detection circuit applies the circuit break detection method for the withstand voltage test of an industrial control system as described in the first aspect above, wherein the circuit break detection circuit includes a controller and a varistor, the varistor circuit includes a first varistor, a second varistor and a third varistor, one connection end of the second varistor and one connection end of the first varistor are respectively connected to the positive electrode and the negative electrode of the battery; the other connection end of the second varistor and the other connection end of the first varistor are connected and connected to a connection end of the third varistor as a cross-linking detection end, the housing covers the screw hole provided below the third thermistor, the grounding end of the third varistor is screwed into the screw hole by a screw and abuts against the housing, a control end of the second varistor is connected to a first control pin of the controller; the other control end of the second varistor is connected to a control end of the first varistor, and the other control end of the first varistor is connected to a control end of the third varistor; the other control end of the third varistor is connected to a second control pin of the controller;

[0014] The positive electrode of the battery and the negative electrode of the battery are respectively connected to a battery detection pin of the controller; the screw hole is connected to a detection pin of the controller as a ground detection end, and the cross-link detection end is connected to another pin of the controller.

[0015] The embodiment of the present invention provides a circuit break detection method and a circuit break detection circuit for a withstand voltage test of an industrial control system. The circuit break detection method includes: applying a preset voltage between the positive electrode and the negative electrode of the battery and judging whether the leakage current is less than a preset current threshold value, if it is less than the current threshold value, judging whether the first isolation value is greater than the isolation threshold value, if it is greater, controlling each varistor to conduct, and judging whether the second isolation is greater than the isolation threshold value, if it is greater, judging whether the third isolation and the fourth isolation are balanced, and if they are balanced, obtaining a passing test result. The above-mentioned circuit break detection method first detects the voltage difference between the positive and negative electrodes of the battery and the first isolation, and if the corresponding conditions are met, controls the varistor to conduct, further detects the second isolation and detects whether the third isolation and the fourth isolation are balanced, thereby obtaining a passing test result, which improves the accuracy of detecting whether the varistor circuit is circuit broken. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0017] Figure 1 A method flow chart of a circuit breaker detection method for a withstand voltage test of an industrial control system provided by an embodiment of the present invention;

[0018] Figure 2 A circuit structure diagram of a circuit break detection circuit for a withstand voltage test of an industrial control system provided by an embodiment of the present invention;

[0019] Figure 3 An assembly structure diagram of a circuit board provided by an embodiment of the present invention;

[0020] Figure 4 Another assembly structure diagram of a circuit board provided in an embodiment of the present invention.

[0021] Figure symbols: MCU, controller; RV1, first varistor; RV2, second varistor; RV3, third varistor; BAT, battery; 11, screw hole; 12, screw; 13, housing, F1, first sampling circuit; F2, second sampling circuit. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0024] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0025] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0026] See also Figure 1 As shown in the figure, the technical method of the present application discloses a circuit break detection method for a withstand voltage test of an industrial control system, wherein the circuit break detection method is applied to a controller, and the controller is electrically connected to the positive electrode of the battery, the negative electrode of the battery, the ground detection terminal and the cross-link detection terminal of the varistor circuit, the control terminal of the battery and each varistor, and the controller can be an MCU control chip. Figure 1 As shown, the circuit breaker detection method includes steps S110-S170.

[0027] S110, applying a preset voltage between the positive electrode of the battery and the negative electrode of the battery, and detecting and obtaining a leakage current between the positive electrode of the battery and the negative electrode of the battery.

[0028] A preset voltage may be applied between the positive electrode and the negative electrode of the battery, which is much higher than the voltage of the battery, and the leakage current of the battery may be detected when the preset voltage is applied. For example, the preset voltage may be 300V, and the voltage difference between the positive electrode and the negative electrode of the battery is 300V.

[0029] S120, determining whether the leakage current is less than a preset current threshold, and obtaining a leakage current determination result.

[0030] Specifically, it can be determined whether the leakage current is less than a preset current threshold. If so, it indicates that the battery voltage test has passed, and the leakage current judgment result is yes; if not, it indicates that the battery voltage test has failed, and the leakage current judgment result is no.

[0031] In a more specific embodiment, after step S120, the following further includes: if the leakage current judgment result is no, issuing a prompt message of a withstand voltage test abnormality.

[0032] If the leakage current judgment result is no, the controller issues a warning message of a withstand voltage test abnormality to prompt the user.

[0033] S130: If the leakage current judgment result is yes, determine whether the first isolation between the cross-link detection terminal and the ground detection terminal is greater than a preset isolation threshold.

[0034] If the leakage current judgment result is yes, judge whether the first isolation between the cross-link detection end and the ground detection end is greater than the preset isolation threshold. If the leakage current judgment result is yes, then further obtain the first isolation between the cross-link detection end and the ground detection end, and the first isolation is also the resistance value between the cross-link detection end and the ground detection end. Determine whether the first isolation is greater than the preset isolation threshold, and the outer shell is also the network PE; if the first isolation is greater than the isolation threshold, it indicates that the two connection ends of the third varistor are not connected. For example, the isolation threshold can be set much larger than the normal resistance of the third varistor. If the maximum resistance of the third varistor is 1000Ω (ohm), the isolation threshold can be set to 10KΩ.

[0035] S140: If the first isolation is greater than the isolation threshold, a corresponding conduction control instruction is issued to each varistor in the varistor circuit to turn on each varistor.

[0036] If the first isolation is greater than the isolation threshold, a corresponding conduction control instruction is issued to each varistor in the varistor circuit to turn on each varistor. If the first isolation is greater than the isolation threshold, a conduction control instruction is issued to each varistor, so that each varistor is controlled to be turned on by the conduction control instruction. The conduction of the varistor means that the 2 pins of the varistor are strongly electrically connected between the 1 pin and the 2 pins.

[0037] S150: Determine whether a second isolation degree between the cross-link detection terminal and the ground detection terminal is greater than the isolation degree threshold.

[0038] It is judged whether the second isolation between the cross-link detection terminal and the ground detection terminal is greater than the isolation threshold. It is further judged whether the second isolation between the cross-link detection terminal and the ground detection terminal is greater than the isolation threshold, and whether the second isolation is greater than the preset isolation threshold. The housing is the network PE; if the second isolation is greater than the isolation threshold, it indicates that the other connection end of the third varistor is not connected to the housing, that is, the other connection end of the third varistor is disconnected from the network PE.

[0039] In a more specific embodiment, before step S150, it also includes: determining whether the second isolation degree is not less than the first isolation degree; if the second isolation degree is not less than the first isolation degree, executing the step of determining whether the second isolation degree between the cross-link detection end and the ground detection end is greater than the isolation degree threshold.

[0040] Before executing step S150, it can also be determined whether the second isolation is not less than the first isolation threshold. If the second isolation is less than the first isolation threshold, it indicates that after the third varistor is turned on, the isolation of the third varistor has changed, and the third varistor may be unstable in the case of a circuit break. If the second isolation is not less than the first isolation, it indicates that the third varistor is not unstable in the case of a circuit break, and step S150 is continued.

[0041] S160. If the second isolation is greater than the isolation threshold, determine whether the third isolation and the fourth isolation are balanced according to a preset balance judgment rule to obtain a corresponding balance judgment result; the third isolation is the isolation between the positive electrode of the battery and the cross-linking detection end, and the fourth isolation is the isolation between the negative electrode of the battery and the cross-linking detection end.

[0042] If the second isolation is greater than the isolation threshold, the third isolation and the fourth isolation are judged to be balanced according to the preset balance judgment rule to obtain the corresponding balance judgment result. If the second isolation is greater than the isolation threshold, the third isolation and the fourth isolation can be further judged to be balanced according to the balance judgment rule, wherein the third isolation corresponds to the isolation at both ends of the first varistor, and the fourth isolation corresponds to the isolation at both ends of the second varistor. The balance judgment rule is a specific rule for judging whether the third isolation and the fourth isolation are balanced.

[0043] In a more specific embodiment, step S160 includes sub-steps: calculating the offset value corresponding to the battery positive electrode and the battery negative electrode voltage according to the voltage offset calculation formula in the balance judgment rule; calculating the isolation offset value corresponding to the third isolation and the fourth isolation according to the isolation offset calculation formula in the balance judgment rule; judging whether the isolation offset value is not greater than the offset value to obtain a balance judgment result of whether the phases are balanced.

[0044] The balance judgment rule includes a voltage offset calculation formula, which can be used to calculate the offset value corresponding to the battery positive electrode voltage and the battery negative electrode voltage, thereby obtaining the offset value. The battery positive electrode voltage can be taken as v1, and the absolute value of the battery negative electrode voltage v2 can be taken as v3. The voltage offset calculation formula is shown in formula (1):

[0045] (1);

[0046] Wherein, R is the calculated offset value, and e is the base of the natural logarithm.

[0047] As the offset value of the battery positive voltage and the battery negative voltage increases, the isolation between the first varistor and the second varistor will be affected. Therefore, the third isolation and the fourth isolation can be further calculated according to the isolation offset calculation formula to obtain the corresponding isolation offset value, and determine whether the isolation deviation value is not greater than the above offset value. If it is not greater than, it indicates that the offset of the isolation between the first varistor and the second varistor does not exceed the reasonable range, and the balance judgment result is phase balance; if it is greater than, it indicates that the offset of the isolation between the first varistor and the second varistor exceeds the reasonable range, and the balance judgment result is phase imbalance. Among them, the calculation formula of the isolation offset value is shown in formula (2):

[0048] (2);

[0049] The third isolation corresponding to the second varistor is represented by g1, and the fourth isolation corresponding to the first varistor is represented by g2. e is the base of the natural logarithm, and G is the calculated isolation offset value.

[0050] In a more specific embodiment, before step S150, it also includes: judging whether the third isolation degree and the fourth isolation degree are both within a preset isolation degree range; if the third isolation degree and the fourth isolation degree are both within the isolation degree range, executing the step of judging whether the third isolation degree and the fourth isolation degree are balanced according to a preset balance judgment rule to obtain a corresponding balance judgment result.

[0051] Furthermore, before judging whether the third isolation and the fourth isolation are balanced, it can also be judged whether the third isolation and the fourth isolation are both within a preset isolation interval, wherein the isolation interval is the rated resistance range of the varistor when the varistor is under pressure. Since the first varistor and the second varistor are set symmetrically in the present application, the rated resistance ranges of the first varistor and the second varistor are also equal, and the fourth isolation of the first varistor and the third isolation of the second varistor can be judged by the same isolation interval. If the third isolation and the fourth isolation are both within the isolation interval, it indicates that the working state of the first varistor and the second varistor is normal, and step S160 can be continued. If the third isolation or the fourth isolation is not within the isolation interval, it indicates that the working state of the first varistor or the second varistor is abnormal, and a prompt message of varistor abnormality can be issued at this time.

[0052] S170: If the balance judgment result is phase balance, a passing test result is obtained.

[0053] If the balance judgment result is phase balance, a pass test result is obtained. If the balance judgment result of the third isolation and the terrain isolation is phase balance, the test result of the pressure sensitive circuit is determined to be passed, and the subsequent withstand voltage test process can be performed.

[0054] In a more specific embodiment, the method further includes: if the first isolation is not greater than the isolation threshold, the second isolation is not greater than the isolation threshold, or the balance judgment result is unbalanced, obtaining a failed detection result.

[0055] If the first isolation is not greater than the isolation threshold, or the second isolation is not greater than the isolation threshold, or the balance judgment result is unbalanced, then it is detected that there is a circuit abnormality in the varistor circuit, and the test result obtained is failure. At this time, the subsequent voltage withstand test process cannot be carried out.

[0056] In a more specific embodiment, after step S170, the method further includes: sending a corresponding disconnection control instruction to each varistor in the varistor circuit to disconnect each varistor.

[0057] Furthermore, if the test result is passed, in order to further improve the safety of the varistor circuit during subsequent testing, a disconnect control instruction can be sent to each varistor. After each varistor receives the disconnect control instruction, the internal electrical connection of the varistor is disconnected, that is, each varistor is controlled to be open-circuited.

[0058] The present application also discloses a circuit breaker detection circuit for a withstand voltage test of an industrial control system. Figure 2As shown, the circuit break detection circuit applies the circuit break detection method of the industrial control system withstand voltage test as described in the above embodiment, wherein the circuit break detection circuit includes a controller MCU and a varistor circuit, the varistor circuit includes a first varistor RV1, a second varistor RV2 and a third varistor RV3, one connection end of the second varistor RV2 and one connection end of the first varistor RV1 are respectively connected to the positive electrode and the negative electrode of the battery BAT; the other connection end of the second varistor RV2 and the other connection end of the first varistor RV1 are connected and connected to a connection end of the third varistor RV3 as a cross-linking detection end, the shell covers the screw hole 11 set below the third thermistor, and the grounding of the third varistor RV3 The end is screwed into the screw hole 11 through a screw 12 and abuts against the shell, a control end of the second varistor RV2 is connected to a first control pin of the controller MCU; the other control end of the second varistor RV2 is connected to a control end of the first varistor RV1, and the other control end of the first varistor RV1 is connected to a control end of the third varistor RV3; the other control end of the third varistor RV3 is connected to the second control pin of the controller MCU; the positive electrode of the battery and the negative electrode of the battery are respectively connected to a battery detection pin of the controller MCU; the screw hole 11 is connected to a detection pin of the controller MCU as a grounding detection end, and the cross-linking detection end is connected to another pin of the controller MCU.

[0059] The above-mentioned pressure-sensitive circuit can be mounted on a circuit board, such as Figure 3 and Figure 4 As shown, Figure 3 The grounding terminal of the third varistor RV3 is not connected to the screw hole 11 set under the circuit board. The signal of the screw hole 11 is the PE network. When the housing is not covered on the screw hole 11 and connected by the screw 12, the grounding terminal of the third varistor RV3 is not connected to the PE network, that is, the varistor circuit is disconnected from the PE network. The specific structure is as follows Figure 3 When the housing is covered on the screw hole 11 and connected by the screw 12, the screw 12 passes through the through hole on the housing and is screwed into the screw hole 11. At this time, the grounding terminal of the third varistor RV3 is connected to the screw hole 11 through the housing and the screw 12. The housing is also the PE network. The cap of the screw 12 can be close to the window position on the circuit board, and the foot of the screw 12 is pressed on the PE network corresponding to the chassis housing. The specific connection structure is as shown in FIG. Figure 4 The outer shell diameter D1 of the screw cap is 9.5 mm. To achieve a stable connection, the minimum diameter D2 of the window on the circuit board is 6.5 mm and the maximum diameter D3 is 12 mm.

[0060] In a more specific embodiment, Figure 2As shown, the circuit break detection circuit also includes a first sampling circuit and a second sampling circuit; the first sampling circuit is arranged in series between the other control end of the third varistor and the second control pin; the second sampling circuit is arranged in series between a control end of the second varistor and the first control pin. Specifically, the control end of the battery BAT is connected to the battery control pin of the controller MCU.

[0061] The signals from S1 and S2 are transmitted to the controller MCU through a corresponding sampling circuit, and then the S1 and S2 signals enter the controller MCU through the sampling circuit, and the controller MCU indirectly controls S1 and S2.

[0062] In the circuit break detection method and circuit break detection circuit for the withstand voltage test of the industrial control system provided in the embodiment of the present invention, the circuit break detection method includes: applying a preset voltage between the positive electrode and the negative electrode of the battery and judging whether the leakage current is less than the preset current threshold, if it is less than the current threshold, judging whether the first isolation value is greater than the isolation threshold, if it is greater, controlling each varistor to conduct, and judging whether the second isolation is greater than the isolation threshold, if it is greater, judging whether the third isolation and the fourth isolation are balanced, and if they are balanced, obtaining a passing test result. The above-mentioned circuit break detection method first detects the voltage difference between the positive and negative electrodes of the battery and the first isolation, and if the corresponding conditions are met, controls the varistor to conduct, further detects the second isolation and detects whether the third isolation and the fourth isolation are balanced, thereby obtaining a passing test result, which improves the accuracy of detecting whether the varistor circuit is circuit broken.

[0063] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A circuit breaker detection method for a withstand voltage test of an industrial control system, characterized in that: The circuit break detection method is applied in a controller, and the controller is electrically connected to the battery positive electrode, the battery negative electrode, the grounding detection end and the cross-linking detection end of the varistor circuit, the control end of the battery and each varistor respectively; one connection end of the second varistor and one connection end of the first varistor are respectively connected to the positive electrode and the negative electrode of the battery; the other connection end of the second varistor and the other connection end of the first varistor are connected and connected to a connection end of the third varistor as a cross-linking detection end, the shell covers the screw hole set below the third thermistor, the grounding end of the third varistor is screwed into the screw hole by a screw and abuts against the shell, and one control end of the second varistor is connected to the first control pin of the controller; the other control end of the second varistor is connected to a control end of the first varistor, and the other control end of the first varistor is connected to a control end of the third varistor; the other control end of the third varistor is connected to the second control pin of the controller; The positive electrode of the battery and the negative electrode of the battery are respectively connected to a battery detection pin of the controller; the screw hole is connected to a detection pin of the controller as a ground detection end, and the cross-link detection end is connected to another pin of the controller; The detection method comprises: Applying a preset voltage between the positive electrode of the battery and the negative electrode of the battery, and detecting and obtaining a leakage current between the positive electrode of the battery and the negative electrode of the battery; Determine whether the leakage current is less than a preset current threshold, and obtain a leakage current determination result; If the leakage current judgment result is yes, determine whether the first isolation between the cross-link detection end and the ground detection end is greater than a preset isolation threshold; the first isolation is the resistance value between the cross-link detection end and the ground detection end obtained by the initial detection; If the first isolation is greater than the isolation threshold, issuing a corresponding conduction control instruction to each varistor in the varistor circuit to turn on each varistor; Determine whether a second isolation degree between the cross-link detection end and the ground detection end is greater than the isolation degree threshold; the second isolation degree is a resistance value between the cross-link detection end and the ground detection end obtained by re-detection; If the second isolation is greater than the isolation threshold, whether the third isolation and the fourth isolation are balanced is judged according to a preset balance judgment rule to obtain a corresponding balance judgment result; the third isolation is the resistance value between the positive electrode of the battery and the cross-link detection end, and the fourth isolation is the resistance value between the negative electrode of the battery and the cross-link detection end; If the balance judgment result is phase balance, a passing test result is obtained.

2. The circuit breaker detection method for the withstand voltage test of the industrial control system according to claim 1, characterized in that: The method further comprises: If the first isolation is not greater than the isolation threshold, the second isolation is not greater than the isolation threshold, or the balance judgment result is unbalanced, a failed detection result is obtained.

3. The circuit breaker detection method for the withstand voltage test of the industrial control system according to claim 1 or 2, characterized in that: After determining whether the leakage current is less than a preset current threshold and obtaining a leakage current determination result, the method further includes: If the leakage current judgment result is no, a prompt message indicating that the withstand voltage test is abnormal is issued.

4. The circuit breaker detection method for the withstand voltage test of the industrial control system according to claim 1 or 2, characterized in that: Before determining whether the second isolation between the cross-link detection terminal and the ground detection terminal is greater than the isolation threshold, the method further includes: Determining whether the second isolation degree is not less than the first isolation degree; If the second isolation is not less than the first isolation, the step of determining whether the second isolation between the cross-link detection terminal and the ground detection terminal is greater than the isolation threshold is performed.

5. The circuit breaking detection method for the withstand voltage test of the industrial control system according to claim 4, characterized in that: The step of judging whether the third isolation degree and the fourth isolation degree are balanced according to a preset balance judgment rule to obtain a corresponding balance judgment result includes: Calculate the offset value corresponding to the voltage of the positive electrode and the negative electrode of the battery according to the voltage offset calculation formula in the balance judgment rule; Calculate the isolation offset values ​​corresponding to the third isolation and the fourth isolation according to the isolation offset calculation formula in the balance judgment rule; It is determined whether the isolation offset value is not greater than the offset value to obtain a balance determination result of whether the phases are balanced.

6. The circuit breaker detection method for the withstand voltage test of the industrial control system according to claim 1, characterized in that: Before judging whether the third isolation degree and the fourth isolation degree are balanced according to the preset balance judgment rule and obtaining the corresponding balance judgment result, the method further includes: Determining whether the third isolation level and the fourth isolation level are both within a preset isolation level range; If the third isolation level and the fourth isolation level are both within the isolation level range, the step of judging whether the third isolation level and the fourth isolation level are balanced according to a preset balance judgment rule to obtain a corresponding balance judgment result is performed.

7. The circuit breaker detection method for the withstand voltage test of the industrial control system according to claim 1 or 2, characterized in that: After obtaining the passing test result, the method further includes: Sending corresponding disconnection control instructions to each varistor in the varistor circuit to disconnect each varistor.

8. A circuit break detection circuit for a withstand voltage test of an industrial control system, wherein the circuit break detection circuit applies the circuit break detection method for a withstand voltage test of an industrial control system as claimed in any one of claims 1 to 7, characterized in that: The circuit break detection circuit includes a controller and a varistor, the varistor circuit includes a first varistor, a second varistor and a third varistor, one connection end of the second varistor and one connection end of the first varistor are respectively connected to the positive electrode and the negative electrode of the battery; the other connection end of the second varistor and the other connection end of the first varistor are connected and connected to a connection end of the third varistor as a cross-link detection end, the shell covers the screw hole set below the third thermistor, the ground end of the third varistor is screwed into the screw hole by a screw and abuts against the shell, a control end of the second varistor is connected to the first control pin of the controller; the other control end of the second varistor is connected to a control end of the first varistor, and the other control end of the first varistor is connected to a control end of the third varistor; the other control end of the third varistor is connected to the second control pin of the controller; The positive electrode of the battery and the negative electrode of the battery are respectively connected to a battery detection pin of the controller; the screw hole is connected to a detection pin of the controller as a ground detection end, and the cross-link detection end is connected to another pin of the controller.

9. The circuit breaker detection circuit for the withstand voltage test of the industrial control system according to claim 8, characterized in that: The disconnection detection circuit also includes a first sampling circuit and a second sampling circuit; The first sampling circuit is arranged in series between the other control end of the third varistor and the second control pin; the second sampling circuit is arranged in series between a control end of the second varistor and the first control pin.

10. The circuit breaker detection circuit for the withstand voltage test of the industrial control system according to claim 8 or 9, characterized in that: The control end of the battery is connected to the battery control pin of the controller.

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