Metal oxide voltage limiter detection method and device

Abstract

The present application provides a method and device for detecting a metal oxide voltage limiter, the method comprising: obtaining the AC bus voltage of the target metal oxide voltage limiter group at the installation point, the first leakage current and the initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group; obtaining the volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current and the initial volt-ampere characteristic curve of each metal oxide voltage limiter; determining the 1mA reference voltage value corresponding to the metal oxide voltage limiter according to the volt-ampere characteristic curve of each metal oxide voltage limiter; determining the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1mA reference voltage value corresponding to each metal oxide voltage limiter and the preset fault detection criteria. The present application can improve the reliability of faulty MOV positioning, and thus can ensure the safety of the operation of the series compensation device.

Description

Technical Field

[0001] The present application relates to the technical field of power equipment detection, and in particular to a metal oxide voltage limiter detection method and device. Background Art

[0002] The series compensation device has the advantages of increasing the transmission capacity of the transmission line and enhancing the stability of the system. In recent years, it has been used in high-voltage and long-distance transmission lines. The series capacitor bank is the core component of the series compensation device, and the metal oxide voltage limiter MOV is usually used as the protection device of the capacitor bank. MOV generally adopts a multi-column parallel structure, and the whole group of MOVs is composed of multiple MOVs in parallel. When the resistor column in a certain MOV is damp or the resistor deteriorates, causing a short circuit fault, the shunting of the whole group of MOVs will be uneven, and the defective MOV will flow through more short-circuit current, causing MOV breakdown, which in turn causes the voltage limiter pressure to be released, and the series compensation device is forced to stop operating.

[0003] At present, the common cause of failure of lightning arrester products is dampness and aging of the internal resistors. The performance of the resistors is generally monitored by the leakage current under the operating voltage. However, in the case of MOV, more than a dozen or even dozens of MOVs are connected in parallel on each phase series compensation platform, and each MOV often has multiple resistors in parallel. The operating voltage of MOV is much lower than its rated voltage. Therefore, the leakage current of each MOV is very small during normal operation, generally at the μA level; even if a single resistor fails, the change in its leakage current is not large, and it is difficult to locate the faulty MOV simply by comparing the change in leakage current. Summary of the invention

[0004] In view of the problems in the prior art, the present application proposes a metal oxide voltage limiter detection method and device, which can improve the reliability of faulty MOV positioning and thus ensure the safety of the operation of the series compensation device.

[0005] In order to solve the above technical problems, this application provides the following technical solutions:

[0006] In a first aspect, the present application provides a metal oxide voltage limiter detection method, comprising:

[0007] Acquire an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0008] Obtaining a volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve;

[0009] According to the volt-ampere characteristic curve of each metal oxide voltage limiter, determining a 1mA reference voltage value corresponding to the metal oxide voltage limiter;

[0010] The faulty metal oxide voltage limiter in the target metal oxide voltage limiter group is determined according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion.

[0011] Further, the volt-ampere characteristic curve of the metal oxide voltage limiter is obtained according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve, including:

[0012] Determining a second leakage current of each metal oxide voltage limiter according to the AC bus voltage and an initial volt-ampere characteristic curve of the metal oxide voltage limiter;

[0013] Determining the translation distance and direction corresponding to the initial volt-ampere characteristic curve according to the AC bus voltage, the theoretical leakage current and the leakage current;

[0014] The volt-ampere characteristic curve is obtained according to the translation distance, direction and initial volt-ampere characteristic curve.

[0015] Further, the determining the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion includes:

[0016] Determining whether the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criterion, and if not, determining that there is a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0017] Randomly select a metal oxide voltage limiter from the target metal oxide voltage limiter group as the metal oxide voltage limiter to be tested;

[0018] Executing a detection step, the detection step comprising: performing a first standard deviation processing on the 1mA reference voltage values ​​of all metal oxide voltage limiters in the metal oxide voltage limiter group except the metal oxide voltage limiter to be tested; determining whether the first standard deviation processing result meets the preset fault detection criterion, and if so, determining that the metal oxide voltage limiter to be tested is a faulty metal oxide voltage limiter;

[0019] A metal oxide voltage limiter to be tested is randomly selected from the metal oxide voltage limiters that have never been subjected to the detection step, and the detection step is returned to be performed until all metal oxide voltage limiters are traversed.

[0020] Furthermore, before obtaining the AC bus voltage of the target metal oxide voltage limiter group at the installation point, the first leakage current and the initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group, the method further includes:

[0021] Regularly obtain a historical 1mA reference voltage value group corresponding to a target metal oxide voltage limiter group;

[0022] Performing second standard deviation processing on each acquired historical 1mA reference voltage value group;

[0023] All second standard deviation processed results are processed by mean and third standard deviation;

[0024] The fault detection criterion is obtained according to the mean value processing result and the third standard deviation processing result.

[0025] Further, after determining the 1 mA reference voltage value corresponding to the metal oxide voltage limiter, the method further includes:

[0026] It is determined whether the standard deviation of the 1 mA reference voltage values ​​corresponding to all the metal oxide voltage limiters meets the preset fault detection criterion. If so, it is determined that all the metal oxide voltage limiters are normal metal oxide voltage limiters.

[0027] In a second aspect, the present application provides a metal oxide voltage limiter detection device, comprising:

[0028] An acquisition module, used for acquiring an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0029] A curve obtaining module, used for obtaining a volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve;

[0030] A determination module, used to determine a 1mA reference voltage value corresponding to each metal oxide voltage limiter according to a volt-ampere characteristic curve of the metal oxide voltage limiter;

[0031] The detection module is used to determine the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion.

[0032] Furthermore, the curve obtaining module includes:

[0033] A leakage current determination unit, configured to determine a second leakage current of the metal oxide voltage limiter according to the AC bus voltage and an initial volt-ampere characteristic curve of each metal oxide voltage limiter;

[0034] A distance determination unit, used to determine the translation distance and direction corresponding to the initial volt-ampere characteristic curve according to the AC bus voltage, the theoretical leakage current and the leakage current;

[0035] The curve obtaining unit is used to obtain the volt-ampere characteristic curve according to the translation distance, direction and the initial volt-ampere characteristic curve.

[0036] Furthermore, the detection module includes:

[0037] a judging unit, configured to judge whether the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criterion, and if not, determine that there is a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0038] A selection unit, used for randomly selecting a metal oxide voltage limiter from the target metal oxide voltage limiter group as the metal oxide voltage limiter to be tested;

[0039] a detection unit, configured to execute a detection step, the detection step comprising: performing a first standard deviation processing on the 1mA reference voltage values ​​of all metal oxide voltage limiters in the metal oxide voltage limiter group except the metal oxide voltage limiter to be tested; determining whether the first standard deviation processing result meets the preset fault detection criterion, and if so, determining that the metal oxide voltage limiter to be tested is a faulty metal oxide voltage limiter;

[0040] The traversal unit is used to randomly select one of the metal oxide voltage limiters that have never been subjected to the detection step as the metal oxide voltage limiter to be tested, and return to perform the detection step until all the metal oxide voltage limiters are traversed.

[0041] In a third aspect, the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the metal oxide voltage limiter detection method is implemented when the processor executes the program.

[0042] In a fourth aspect, the present application provides a computer-readable storage medium having computer instructions stored thereon, wherein the instructions, when executed, implement the metal oxide voltage limiter detection method.

[0043] As can be seen from the above technical solution, the present application provides a method and device for detecting a metal oxide voltage limiter. The method includes: obtaining the AC bus voltage of the target metal oxide voltage limiter group at the installation point, the first leakage current and the initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group; obtaining the volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current and the initial volt-ampere characteristic curve of each metal oxide voltage limiter; determining the 1mA reference voltage value corresponding to the metal oxide voltage limiter according to the volt-ampere characteristic curve of each metal oxide voltage limiter; determining the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1mA reference voltage value corresponding to each metal oxide voltage limiter and the preset fault detection criteria, which can improve the reliability of faulty MOV positioning, ensure the safety of series compensation device operation, and thus improve the stability of the transmission line; specifically, based on the volt-ampere characteristic curve, the subtle changes in the small current area are amplified to the voltage under the 1mA current, so as to facilitate the timely discovery of the change in the state of the resistor, and the faulty MOV can be determined in time; the U 1mA Taking the standard deviation for processing can prevent the normal phenomenon of consistent aging of MOVs in the same group from being misjudged as abnormal. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 is a schematic flow chart of a method for detecting a metal oxide voltage limiter in an embodiment of the present application;

[0046] Figure 2 is a flow chart of steps 201 to 203 of the metal oxide voltage limiter detection method in an embodiment of the present application;

[0047] Figure 3 It is a structural schematic diagram of a metal oxide voltage limiter group in the prior art;

[0048] Figure 4 is a comparative schematic diagram of an original curve and an offset curve in an example of the present application;

[0049] Figure 5 is a flow chart of steps 401 to 404 of a method for detecting a metal oxide voltage limiter in another embodiment of the present application;

[0050] Figure 6 is a schematic structural diagram of a metal oxide voltage limiter detection device in an embodiment of the present application;

[0051] Figure 7 This is a schematic block diagram of the system structure of the electronic device 9600 according to an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] In order to solve the problems existing in the above-mentioned prior art, considering that the MOV will be tested and measured for the volt-ampere characteristic curve when it leaves the factory, the volt-ampere characteristic curve of the MOV has good consistency with the volt-ampere characteristic curve of the resistor that constitutes the MOV. (For example: the volt-ampere characteristic curve of two series resistors is compared with that of a single resistor, and the voltage of the two resistors in series under the same current is twice that of the single resistor; the volt-ampere characteristic curve of two parallel resistors is compared with that of a single resistor, and the corresponding current under the same voltage is twice that of the single resistor. The total volt-ampere characteristic curve under the multi-piece series-parallel structure can be calculated based on the volt-ampere characteristics and series-parallel relationship of the single resistor). When the resistor deteriorates or is damp inside the MOV, its volt-ampere characteristic curve will shift to the right, and the corresponding current under the same voltage will increase. This application proposes a metal oxide voltage limiter detection method and device, which can amplify the subtle changes in the small current area to the voltage under the current of 1mA based on the volt-ampere characteristic curve, so as to timely discover the change in the state of the resistor and timely determine the faulty MOV; the U 1mA Taking the standard deviation for processing can prevent the normal phenomenon of consistent aging of MOVs in the same group from being misjudged as abnormal.

[0054] Based on this, in order to improve the reliability of faulty MOV positioning and thereby ensure the safety of the operation of the series compensation device, the embodiment of the present application provides a metal oxide voltage limiter detection device, which can be a server or client device, and the client device can include a smart phone, a tablet electronic device, a network set-top box, a portable computer, a desktop computer, a personal digital assistant (PDA), a vehicle-mounted device, and a smart wearable device, etc. Among them, the smart wearable device can include smart glasses, smart watches, and smart bracelets, etc.

[0055] In practical applications, the part of metal oxide voltage limiter detection can be performed on the server side as described above, or all operations can be completed in the client device. The selection can be made based on the processing capability of the client device and the limitations of the user's usage scenario. This application does not limit this. If all operations are completed in the client device, the client device may also include a processor.

[0056] The client device may have a communication module (i.e., a communication unit) that can communicate with a remote server to achieve data transmission with the server. The server may include a server on the task scheduling center side, and other implementation scenarios may also include a server on an intermediate platform, such as a server on a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, or a server cluster consisting of multiple servers, or a server structure of a distributed device.

[0057] The server and the client device may communicate using any suitable network protocol, including network protocols that have not yet been developed on the date of filing this application. The network protocol may include, for example, TCP / IP protocol, UDP / IP protocol, HTTP protocol, HTTPS protocol, etc. Of course, the network protocol may also include, for example, RPC protocol (Remote Procedure Call Protocol) and REST protocol (Representational State Transfer) used on top of the above protocols.

[0058] The details are described through the following embodiments.

[0059] In order to improve the reliability of faulty MOV positioning and thereby ensure the safety of the operation of the series compensation device, this embodiment provides a metal oxide voltage limiter detection method in which the execution subject is a metal oxide voltage limiter detection device, and the metal oxide voltage limiter detection device includes but is not limited to a server, such as Figure 1 As shown, the method specifically includes the following contents:

[0060] Step 100: Acquire an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group.

[0061] Step 200: Obtaining the volt-ampere characteristic curve of each metal oxide voltage limiter according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve.

[0062] Step 300: Determine a 1 mA reference voltage value corresponding to each metal oxide voltage limiter according to the volt-ampere characteristic curve of the metal oxide voltage limiter.

[0063] Step 400: Determine the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion.

[0064] Specifically, Figure 3 As shown, the metal oxide voltage limiter group can be composed of multiple MOVs connected in parallel, each MOV includes multiple resistor columns composed of resistors connected in series, and multiple resistor columns in the same MOV are connected in parallel; the AC bus voltage at the MOV installation point can represent the voltage difference between the two ends of the MOV group a and b; the MOV will undergo a test measurement of the volt-ampere characteristic curve when leaving the factory, and the volt-ampere characteristic curve measured at the factory can be used as the initial volt-ampere characteristic curve of the MOV; the AC bus voltage of the target metal oxide voltage limiter group at the installation point, the leakage current corresponding to each metal oxide voltage limiter, and the initial volt-ampere characteristic curve can be obtained.

[0065] Specifically, Figure 4 As shown, the voltage value corresponding to 1 mA current on the volt-ampere characteristic curve (offset curve) of each metal oxide voltage limiter can be used as the 1 mA reference voltage value U of the metal oxide voltage limiter. 1mA_read .

[0066] It can be seen from the above description that the metal oxide voltage limiter detection method provided in this embodiment can improve the reliability of faulty MOV positioning, thereby ensuring the safety of the operation of the series compensation device; specifically, the 1mA reference voltage value corresponding to the metal oxide voltage limiter can be determined based on the volt-ampere characteristic curve, and the fault detection of the metal oxide voltage limiter during operation can be realized, which can improve the real-time and convenience of fault detection.

[0067] In order to further improve the reliability of obtaining the volt-ampere characteristic curve and thus improve the accuracy of metal oxide voltage limiter detection, see Figure 2 In one embodiment of the present application, step 200 includes:

[0068] Step 201: Determine a second leakage current of each metal oxide voltage limiter according to the AC bus voltage and an initial volt-ampere characteristic curve of the metal oxide voltage limiter.

[0069] Specifically, the theoretical leakage current corresponding to the AC bus voltage on the initial volt-ampere characteristic curve of each metal oxide voltage limiter may be used as the second leakage current of the metal oxide voltage limiter.

[0070] Step 202: Determine the translation distance and direction corresponding to the initial volt-ampere characteristic curve according to the AC bus voltage, the theoretical leakage current and the leakage current.

[0071] Step 203: Obtain the volt-ampere characteristic curve according to the translation distance, direction and initial volt-ampere characteristic curve.

[0072] Specifically, according to the AC bus voltage U AC , the first leakage current I r1 and the second leakage current I r1 ', we can determine the translation distance as |I r1 -I r1 '|, if I r1 >I r1 ', the initial volt-ampere characteristic curve shifts to the right, otherwise, it shifts to the left; in an example, the corresponding relationship between the initial volt-ampere characteristic curve and the volt-ampere characteristic curve is as follows Figure 4 As shown in the figure, the initial volt-ampere characteristic curve (original curve) is the volt-ampere characteristic curve measured when the MOV leaves the factory. Point ① is (U AC , I r1 '), point ② is (U AC ,I r1 ), after obtaining point ①, point ② and the initial volt-ampere characteristic curve, the initial volt-ampere characteristic curve is translated so that point ② falls on the translated curve, and the offset curve is obtained, which is the above-mentioned volt-ampere characteristic curve. The ordinate corresponding to point ③ on the offset curve with a horizontal coordinate of 1 mA is U 1mA_read .

[0073] To further improve the accuracy of metal oxide voltage limiter detection, see Figure 5 In one embodiment of the present application, step 400 includes:

[0074] Step 401: determine whether the standard deviation of the 1 mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criterion; if not, determine that there is a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group.

[0075] In order to further improve the accuracy of fault detection, it is possible to determine whether the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criteria. If not, the 1mA reference voltage values ​​corresponding to each metal oxide voltage limiter group are re-acquired, and it is determined again whether the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criteria. If not, it is determined that there is a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group.

[0076] Step 402: randomly selecting a metal oxide voltage limiter from the target metal oxide voltage limiter group as the metal oxide voltage limiter to be tested.

[0077] Step 403: Execute a detection step, which includes: performing a first standard deviation processing on the 1mA reference voltage values ​​of all metal oxide voltage limiters in the metal oxide voltage limiter group except the metal oxide voltage limiter to be tested; determining whether the first standard deviation processing result meets the preset fault detection criteria, and if so, determining that the metal oxide voltage limiter to be tested is a faulty metal oxide voltage limiter.

[0078] Specifically, the first standard deviation processing is a standard deviation processing performed on 1 mA reference voltage values ​​of all metal oxide voltage limiters in the metal oxide voltage limiter group except the metal oxide voltage limiter to be tested.

[0079] Step 404: randomly selecting one of the metal oxide voltage limiters that have not been subjected to the detection step as the metal oxide voltage limiter to be tested, and returning to execute the detection step until all metal oxide voltage limiters are traversed.

[0080] In order to further improve the accuracy of metal oxide voltage limiter detection, in one embodiment of the present application, the metal oxide voltage limiter detection method further includes:

[0081] If the standard deviation processing result does not meet the preset fault detection criterion, one of the metal oxide voltage limiters that has not been subjected to the detection step is randomly selected as the metal oxide voltage limiter to be tested, and the detection step is returned to be executed.

[0082] In order to further improve the accuracy of metal oxide voltage limiter detection, in one embodiment of the present application, before step 100, the following steps are further included:

[0083] Step 001: regularly obtaining a historical 1mA reference voltage value group corresponding to a target metal oxide voltage limiter group.

[0084] Specifically, the historical 1mA reference voltage value group may include historical 1mA reference voltage values ​​corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group; the historical AC bus voltage of the target metal oxide voltage limiter group at the installation point, and the historical first leakage current and initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group may be obtained; based on the AC bus voltage, the historical first leakage current and the initial volt-ampere characteristic curve of each metal oxide voltage limiter, the historical volt-ampere characteristic curve of the metal oxide voltage limiter is obtained; based on the historical volt-ampere characteristic curve of each metal oxide voltage limiter, the historical 1mA reference voltage value corresponding to the metal oxide voltage limiter is determined.

[0085] Step 002: Perform second standard deviation processing on each acquired historical 1mA reference voltage value group.

[0086] Specifically, the second standard deviation processing is the standard deviation processing performed on each historical 1mA reference voltage value group obtained.

[0087] Step 003: Perform mean processing and third standard deviation processing on all second standard deviation processing results.

[0088] Specifically, the third standard deviation processing is a standard deviation processing performed on all second standard deviation processing results.

[0089] Step 004: Obtain the fault detection criterion according to the mean value processing result and the third standard deviation processing result.

[0090] Specifically, the fault detection criterion can be a three sigma criterion, and the mean processing result is determined as μ in the three sigma criterion, and the third standard deviation processing result is determined as σ in the three sigma criterion; if the first standard deviation processing result is greater than (μ-3σ) and less than (μ+3σ), then it is determined that the first standard deviation processing result meets the three sigma criterion, otherwise it does not meet the three sigma criterion; if the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters is greater than (μ-3σ) and less than (μ+3σ), then it is determined that the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the three sigma criterion, otherwise it does not meet the three sigma criterion.

[0091] In order to improve the efficiency of metal oxide voltage limiter detection while ensuring the reliability of metal oxide voltage limiter detection, in one embodiment of the present application, after step 300, the following steps are further included:

[0092] Step 500: Determine whether the standard deviation of the 1 mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criterion. If so, determine that all metal oxide voltage limiters are normal metal oxide voltage limiters.

[0093] To further illustrate the present solution, the present application provides an application example of a metal oxide voltage limiter detection method. In this application example, the metal oxide voltage limiter group includes n MOVs. The method is specifically described as follows:

[0094] Step S1: numbering the MOVs in the metal oxide voltage limiter group in sequence from 1 to n.

[0095] Step S2: Measure the AC bus voltage U at the installation point of the metal oxide voltage limiter group AC And the leakage current I corresponding to MOV No. 1 r1 .

[0096] Step S3: According to the volt-ampere characteristic curve measured when MOV No. 1 leaves the factory, read the corresponding U AC Theoretical leakage current I corresponding to MOV No. 1 r1 '.

[0097] Step S4: According to (U AC ,I r1 ) and (U AC , I r1 ') to determine the relative displacement between them, and to obtain the new volt-ampere characteristic curve.

[0098] Step S5: Read the U corresponding to 1 mA current on the new volt-ampere characteristic curve 1mA_read value.

[0099] Step S6: Repeat steps S2 to S5 to obtain the U of n MOVs. 1mA_read value.

[0100] Step S7: For all the obtained U 1mA_read The standard deviation is calculated by the value, and the standard deviation δ is obtained. 1mA_read , the calculation formula is as follows:

[0101]

[0102] Among them, U 1mA_read,n U of MOV numbered n 1mA_read value, For n U 1mA_read The average value of .

[0103] Step S8: Execute steps S2 to S7 once every cycle (which can be set by yourself to ensure that the intervals are equal each time) to accumulate multiple delta 1mA_read For the convenience of description, the δ obtained by this calculation is referred to as 1mA_read For X t , the δ calculated in the previous cycle 1mA_read For X t-1 , δ calculated from the factory acceptance test results 1mA_read For X 1 .

[0104] Step S9: Calculate X 1 ~X t-1 The mean μ and standard deviation σ of X t Does not satisfy μ-3σ <X t <μ+3σ, it is considered that there is a measurement error or an MOV failure. Among them, the U values ​​of n MOVs obtained from the first to (t-1) times are 1mA_readThe value may be equivalent to the historical 1 mA reference voltage value group obtained at the above timing, that is, the U of n MOVs obtained at any time from the first time to (t-1) times. 1mA_read The value can be equivalent to obtaining a historical 1mA reference voltage value group at one time; X 1 ~X t-1 It can be equivalent to all the above second standard deviation processing results.

[0105] Step S10: Execute steps S2 to S7 again to recalculate X t , if μ-3σ is still not satisfied <X t <μ+3σ, the measurement error is eliminated and it is considered that an MOV is faulty.

[0106] Step S11: calculate the U of each MOV obtained in this calculation 1mA_read Value, select n-1 U from them 1mA_read , calculate the standard deviation to get δ k , where K represents the number of the unselected MOV. Based on this, we can get δ 1 ~δ n .

[0107] Step S12: Determine δ k Whether μ-3σ<δ is satisfied k <μ+3σ, if δ k If this condition is met, it is determined that the resistor of MOV No. k is faulty.

[0108] From the software level, in order to improve the reliability of faulty MOV positioning and thereby ensure the safety of the operation of the series compensation device, the present application provides an embodiment of a metal oxide voltage limiter detection device for implementing all or part of the contents of the metal oxide voltage limiter detection method, see Figure 6 The metal oxide voltage limiter detection device specifically includes the following contents:

[0109] An acquisition module 01 is used to acquire an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0110] A curve obtaining module 02, for obtaining a volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve;

[0111] A determination module 03, for determining a 1mA reference voltage value corresponding to each metal oxide voltage limiter according to a volt-ampere characteristic curve of the metal oxide voltage limiter;

[0112] The detection module 04 is used to determine the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion.

[0113] In one embodiment of the present application, the curve obtaining module includes:

[0114] A leakage current determination unit, configured to determine a second leakage current of the metal oxide voltage limiter according to the AC bus voltage and an initial volt-ampere characteristic curve of each metal oxide voltage limiter;

[0115] A distance determination unit, used to determine the translation distance and direction corresponding to the initial volt-ampere characteristic curve according to the AC bus voltage, the theoretical leakage current and the leakage current;

[0116] The curve obtaining unit is used to obtain the volt-ampere characteristic curve according to the translation distance, direction and the initial volt-ampere characteristic curve.

[0117] In one embodiment of the present application, the determining unit includes:

[0118] a judging unit, configured to judge whether the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criterion, and if not, determine that there is a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0119] A selection unit, used for randomly selecting a metal oxide voltage limiter from the target metal oxide voltage limiter group as the metal oxide voltage limiter to be tested;

[0120] a detection unit, configured to execute a detection step, the detection step comprising: performing a first standard deviation processing on the 1mA reference voltage values ​​of all metal oxide voltage limiters in the metal oxide voltage limiter group except the metal oxide voltage limiter to be tested; determining whether the first standard deviation processing result meets the preset fault detection criterion, and if so, determining that the metal oxide voltage limiter to be tested is a faulty metal oxide voltage limiter;

[0121] The traversal unit is used to randomly select one of the metal oxide voltage limiters that have never been subjected to the detection step as the metal oxide voltage limiter to be tested, and return to perform the detection step until all the metal oxide voltage limiters are traversed.

[0122] The embodiment of the metal oxide voltage limiter detection device provided in this specification can be specifically used to execute the processing flow of the embodiment of the metal oxide voltage limiter detection method described above. Its functions are not repeated here, and reference can be made to the detailed description of the embodiment of the metal oxide voltage limiter detection method described above.

[0123] It can be seen from the above description that the metal oxide voltage limiter detection method and device provided by the present application can improve the reliability of faulty MOV positioning, ensure the safety of the operation of the series compensation device, and thus improve the stability of the transmission line; specifically, based on the volt-ampere characteristic curve, the subtle changes in the small current area are amplified to the voltage under the current of 1mA, so as to facilitate the timely discovery of the state change of the resistor and timely determine the faulty MOV; the standard deviation of U1mA obtained by the same batch of MOVs is used for processing, so as to avoid the common aging of MOVs in the same group, but the normal phenomenon with consistent changes is avoided from being misjudged as an abnormal state.

[0124] From the hardware level, in order to improve the reliability of faulty MOV positioning and thereby ensure the safety of the operation of the series compensation device, the present application provides an embodiment of an electronic device for implementing all or part of the contents of the metal oxide voltage limiter detection method. The electronic device specifically includes the following contents:

[0125] A processor, a memory, a communications interface and a bus; wherein the processor, the memory and the communications interface communicate with each other through the bus; the communications interface is used to realize information transmission between the metal oxide voltage limiter detection device and related devices such as a user terminal; the electronic device can be a desktop computer, a tablet computer and a mobile terminal, etc., but the present embodiment is not limited thereto. In the present embodiment, the electronic device can be implemented with reference to the embodiments for realizing the metal oxide voltage limiter detection method and the embodiments for realizing the metal oxide voltage limiter detection device, and the contents thereof are incorporated herein, and the repeated parts are not repeated.

[0126] Figure 7 FIG. 9 is a schematic block diagram of the system structure of the electronic device 9600 according to an embodiment of the present application. Figure 7 As shown, the electronic device 9600 may include a central processor 9100 and a memory 9140; the memory 9140 is coupled to the central processor 9100. It is worth noting that Figure 7 is exemplary; other types of structures may also be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0127] In one or more embodiments of the present application, the metal oxide voltage limiter detection function may be integrated into the central processor 9100. The central processor 9100 may be configured to perform the following control:

[0128] Step 100: obtaining an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0129] Step 200: Obtaining a volt-ampere characteristic curve of each metal oxide voltage limiter according to the AC bus voltage, a first leakage current and an initial volt-ampere characteristic curve of each metal oxide voltage limiter;

[0130] Step 300: Determine a 1 mA reference voltage value corresponding to each metal oxide voltage limiter according to the volt-ampere characteristic curve of the metal oxide voltage limiter;

[0131] Step 400: Determine the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion.

[0132] It can be seen from the above description that the electronic device provided by the embodiment of the present application can improve the reliability of locating the faulty MOV, thereby ensuring the safety of the operation of the series compensation device.

[0133] In another embodiment, the metal oxide voltage limiter detection device can be configured separately from the central processing unit 9100. For example, the metal oxide voltage limiter detection device can be configured as a chip connected to the central processing unit 9100, and the metal oxide voltage limiter detection function can be realized under the control of the central processing unit.

[0134] like Figure 7 As shown, the electronic device 9600 may also include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily have to include Figure 7 In addition, the electronic device 9600 may also include Figure 7 For components not shown, reference may be made to the prior art.

[0135] like Figure 7 As shown, the central processing unit 9100 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor device and / or logic device. The central processing unit 9100 receives input and controls the operation of various components of the electronic device 9600.

[0136] The memory 9140 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. The above-mentioned information related to the failure may be stored, and a program for executing the relevant information may also be stored. The CPU 9100 may execute the program stored in the memory 9140 to implement information storage or processing, etc.

[0137] The input unit 9120 provides input to the central processing unit 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is used to provide power to the electronic device 9600. The display 9160 is used to display display objects such as images and texts. The display may be, for example, an LCD display, but is not limited thereto.

[0138] The memory 9140 may be a solid-state memory, such as a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It may also be a memory that saves information even when the power is off, can be selectively erased, and is provided with more data, examples of which are sometimes referred to as EPROMs, etc. The memory 9140 may also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 may include an application / function storage unit 9142, which is used to store application programs and function programs or processes for executing the operation of the electronic device 9600 through the central processor 9100.

[0139] The memory 9140 may also include a data storage unit 9143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 may include various drivers for communication functions of the electronic device and / or for executing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0140] The communication module 9110 is a transmitter / receiver 9110 that sends and receives signals via an antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processor 9100 to provide input signals and receive output signals, which may be the same as the case of a conventional mobile communication terminal.

[0141] Based on different communication technologies, multiple communication modules 9110 may be provided in the same electronic device, such as a cellular network module, a Bluetooth module and / or a wireless LAN module, etc. The communication module (transmitter / receiver) 9110 is also coupled to a speaker 9131 and a microphone 9132 via an audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, thereby realizing a common telecommunication function. The audio processor 9130 may include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 9130 is also coupled to the central processor 9100, so that recording can be performed on the local machine through the microphone 9132, and the sound stored on the local machine can be played through the speaker 9131.

[0142] It can be seen from the above description that the electronic device provided by the embodiment of the present application can improve the reliability of locating the faulty MOV, thereby ensuring the safety of the operation of the series compensation device.

[0143] The embodiments of the present application also provide a computer-readable storage medium capable of implementing all the steps in the metal oxide voltage limiter detection method in the above embodiments. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, all the steps in the metal oxide voltage limiter detection method in the above embodiments are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0144] Step 100: obtaining an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group;

[0145] Step 200: Obtaining a volt-ampere characteristic curve of each metal oxide voltage limiter according to the AC bus voltage, a first leakage current and an initial volt-ampere characteristic curve of each metal oxide voltage limiter;

[0146] Step 300: Determine a 1 mA reference voltage value corresponding to each metal oxide voltage limiter according to the volt-ampere characteristic curve of the metal oxide voltage limiter;

[0147] Step 400: Determine the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion.

[0148] It can be seen from the above description that the computer-readable storage medium provided in the embodiments of the present application can improve the reliability of locating a faulty MOV, thereby ensuring the safety of the operation of the series compensation device.

[0149] In this application, each embodiment of the above method is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. For relevant parts, refer to the partial description of the method embodiment.

[0150] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0151] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0152] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0153] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0154] Specific embodiments are used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core idea of ​​this application. At the same time, for those skilled in the art, according to the idea of ​​this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this application.

Claims

1. A method for detecting a metal oxide voltage limiter, characterized in that: include: Acquire an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group; Obtaining a volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve; According to the volt-ampere characteristic curve of each metal oxide voltage limiter, determining a 1mA reference voltage value corresponding to the metal oxide voltage limiter; Determining the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion; Before obtaining the AC bus voltage of the target metal oxide voltage limiter group at the installation point, the first leakage current and the initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group, the method further includes: Regularly obtain a historical 1mA reference voltage value group corresponding to a target metal oxide voltage limiter group; Performing second standard deviation processing on each acquired historical 1mA reference voltage value group; All second standard deviation processed results are processed by mean and third standard deviation; The fault detection criterion is obtained according to the mean processing result and the third standard deviation processing result; the fault detection criterion is the three sigma criterion, the mean processing result is determined as μ in the three sigma criterion, and the third standard deviation processing result is determined as σ in the three sigma criterion.

2. The metal oxide voltage limiter detection method according to claim 1, characterized in that: The step of obtaining the volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve comprises: Determining a second leakage current of each metal oxide voltage limiter according to the AC bus voltage and an initial volt-ampere characteristic curve of the metal oxide voltage limiter; Determining the translation distance and direction corresponding to the initial volt-ampere characteristic curve according to the AC bus voltage, the theoretical leakage current and the leakage current; The volt-ampere characteristic curve is obtained according to the translation distance, direction and initial volt-ampere characteristic curve.

3. The metal oxide voltage limiter detection method according to claim 1, characterized in that: The method of determining the faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to the 1 mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion includes: Determining whether the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criterion, and if not, determining that there is a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group; Randomly select a metal oxide voltage limiter from the target metal oxide voltage limiter group as the metal oxide voltage limiter to be tested; Executing a detection step, the detection step comprising: performing a first standard deviation processing on the 1mA reference voltage values ​​of all metal oxide voltage limiters in the metal oxide voltage limiter group except the metal oxide voltage limiter to be tested; determining whether the first standard deviation processing result meets the preset fault detection criterion, and if so, determining that the metal oxide voltage limiter to be tested is a faulty metal oxide voltage limiter; A metal oxide voltage limiter to be tested is randomly selected from the metal oxide voltage limiters that have never been subjected to the detection step, and the detection step is returned to be performed until all metal oxide voltage limiters are traversed.

4. The metal oxide voltage limiter detection method according to claim 1, characterized in that: After determining the 1 mA reference voltage value corresponding to the metal oxide voltage limiter, the method further includes: It is determined whether the standard deviation of the 1 mA reference voltage values ​​corresponding to all the metal oxide voltage limiters meets the preset fault detection criterion. If so, it is determined that all the metal oxide voltage limiters are normal metal oxide voltage limiters.

5. A metal oxide voltage limiter detection device, characterized in that: include: An acquisition module, used for acquiring an AC bus voltage of a target metal oxide voltage limiter group at an installation point, a first leakage current and an initial volt-ampere characteristic curve corresponding to each metal oxide voltage limiter in the target metal oxide voltage limiter group; A curve obtaining module, used for obtaining a volt-ampere characteristic curve of the metal oxide voltage limiter according to the AC bus voltage, the first leakage current of each metal oxide voltage limiter and the initial volt-ampere characteristic curve; A determination module, used to determine a 1mA reference voltage value corresponding to each metal oxide voltage limiter according to a volt-ampere characteristic curve of the metal oxide voltage limiter; A detection module, used for determining a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group according to a 1mA reference voltage value corresponding to each metal oxide voltage limiter and a preset fault detection criterion; The metal oxide voltage limiter detection device is also used for: Regularly obtain a historical 1mA reference voltage value group corresponding to a target metal oxide voltage limiter group; Performing second standard deviation processing on each acquired historical 1mA reference voltage value group; All second standard deviation processed results are processed by mean and third standard deviation; The fault detection criterion is obtained according to the mean processing result and the third standard deviation processing result; the fault detection criterion is the three sigma criterion, the mean processing result is determined as μ in the three sigma criterion, and the third standard deviation processing result is determined as σ in the three sigma criterion.

6. The metal oxide voltage limiter detection device according to claim 5, characterized in that: The curve acquisition module comprises: A leakage current determination unit, configured to determine a second leakage current of the metal oxide voltage limiter according to the AC bus voltage and an initial volt-ampere characteristic curve of each metal oxide voltage limiter; A distance determination unit, used to determine the translation distance and direction corresponding to the initial volt-ampere characteristic curve according to the AC bus voltage, the theoretical leakage current and the leakage current; The curve obtaining unit is used to obtain the volt-ampere characteristic curve according to the translation distance, direction and the initial volt-ampere characteristic curve.

7. The metal oxide voltage limiter detection device according to claim 5, characterized in that: The detection module comprises: a judging unit, configured to judge whether the standard deviation of the 1mA reference voltage values ​​corresponding to all metal oxide voltage limiters meets the preset fault detection criterion, and if not, determine that there is a faulty metal oxide voltage limiter in the target metal oxide voltage limiter group; A selection unit, used for randomly selecting a metal oxide voltage limiter from the target metal oxide voltage limiter group as the metal oxide voltage limiter to be tested; a detection unit, configured to execute a detection step, the detection step comprising: performing a first standard deviation processing on the 1mA reference voltage values ​​of all metal oxide voltage limiters in the metal oxide voltage limiter group except the metal oxide voltage limiter to be tested; determining whether the first standard deviation processing result meets the preset fault detection criterion, and if so, determining that the metal oxide voltage limiter to be tested is a faulty metal oxide voltage limiter; The traversal unit is used to randomly select one of the metal oxide voltage limiters that have never been subjected to the detection step as the metal oxide voltage limiter to be tested, and return to perform the detection step until all the metal oxide voltage limiters are traversed.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the metal oxide voltage limiter detection method according to any one of claims 1 to 4 is implemented.

9. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the instructions are executed, the metal oxide voltage limiter detection method according to any one of claims 1 to 4 is implemented.

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