Primary side defect detection method and device of capacitor voltage transformer and terminal equipment

Abstract

The invention discloses a primary side defect detection method and device of a capacitor voltage transformer and terminal equipment, and belongs to the field of capacitor voltage transformers, and the method comprises the steps: collecting a secondary voltage waveform signal of the capacitor voltage transformer in a target transformer substation; detecting the waveform amplitude change of the secondary voltage waveform signal, and screening according to the waveform amplitude change to obtain a target abnormal capacitor voltage transformer with voltage waveform abrupt change; and finally, positioning a target area in which the secondary voltage waveform signal of the target abnormal capacitor voltage transformer has voltage waveform mutation, and according to the secondary voltage waveform signal in the target area, judging whether voltage steering exists in the target area, and judging whether the target abnormal capacitor voltage transformer has the primary side defect or not. By implementing the method and the device, the problem that the primary side defect of the electromagnetic unit of the capacitive voltage transformer cannot be identified in the prior art can be effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of capacitor voltage transformers, and in particular to a primary side defect detection method, device and terminal equipment of a capacitor voltage transformer. Background Art

[0002] Capacitive Voltage Transformers (CVTs) are key devices for grid voltage monitoring, providing voltage signals for relay protection, metering, and measurement. CVT defects primarily include defects in the capacitor divider, internal electromagnetic unit defects, and external short circuits. Existing technologies only monitor capacitor divider defects and fail to cover all CVT defect types, particularly those on the primary side of the electromagnetic unit.

[0003] Defects on the primary side of the CVT electromagnetic unit are usually caused by the breakdown of the insulating plate inside the electromagnetic unit mailbox. Since the discharge location is inside the CVT oil tank, it is difficult to detect through appearance and infrared inspection. In addition, the sampling rate of the existing CVT defect monitoring method is low, and such defects cannot be detected. As a result, long-term discharge is not discovered until the voltage signal disappears and the equipment fails, which brings risks to the normal operation of protection equipment. Summary of the Invention

[0004] The present invention provides a method, device and terminal equipment for detecting defects on the primary side of a capacitor voltage transformer. The method can solve the problem that the prior art cannot identify defects on the primary side of a CVT electromagnetic unit.

[0005] An embodiment of the present invention provides a method for detecting defects on the primary side of a capacitor voltage transformer, comprising:

[0006] Collect the secondary voltage waveform signal of the capacitor voltage transformer in the target substation;

[0007] detecting a change in the waveform amplitude of the secondary voltage waveform signal, and screening out target abnormal capacitor voltage transformers having a sudden change in voltage waveform based on the change in the waveform amplitude;

[0008] Locating a target area where a voltage waveform mutation occurs in the secondary voltage waveform signal of the target abnormal capacitor voltage transformer, and determining whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area,

[0009] If so, it is determined that the target abnormal capacitor voltage transformer has a primary side defect,

[0010] If not, it is determined that the target abnormal capacitor voltage transformer has no primary side defect.

[0011] Furthermore, the collecting of the secondary voltage waveform signal of the capacitor voltage transformer in the target substation includes:

[0012] Determine the preset sampling frequency;

[0013] The secondary voltage waveform signal of each capacitor voltage transformer in the target substation is collected according to the sampling frequency.

[0014] Furthermore, the detecting of the waveform amplitude change of the secondary voltage waveform signal and screening out target abnormal capacitor voltage transformers having voltage waveform mutations according to the waveform amplitude change includes:

[0015] Obtaining a preset sampling point interval and a preset amplitude change threshold;

[0016] For each of the capacitor voltage transformers, traversing the secondary voltage waveform signal of the capacitor voltage transformer using the sampling point interval, and upon detecting that a waveform amplitude change of the secondary voltage waveform signal within the sampling point interval exceeds the amplitude change threshold, determining that the capacitor voltage transformer has a voltage waveform mutation, and identifying the capacitor voltage transformer as an abnormal capacitor voltage transformer;

[0017] For each abnormal capacitor voltage transformer, the installation position of the abnormal capacitor voltage transformer is located, and when it is detected that the capacitor voltage transformer with a sudden change in voltage waveform at the installation position is only the abnormal capacitor voltage transformer, the abnormal capacitor voltage transformer is used as the target abnormal capacitor voltage transformer.

[0018] Furthermore, the positioning of the target area where the secondary voltage waveform signal of the target abnormal capacitor voltage transformer has a sudden voltage waveform change includes:

[0019] Obtaining a preset judgment cycle window;

[0020] Locating a mutation position where a voltage waveform mutation occurs in the target abnormal capacitor voltage transformer;

[0021] Taking the mutation position as a starting point, the target area of the target abnormal capacitor voltage transformer is selected using the judgment period window frame; wherein, the target area includes the mutation position, the pre-mutation area and the post-mutation area.

[0022] Furthermore, judging whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area includes:

[0023] Integrating the sampled voltage values of the secondary voltage waveform signal in the target area to obtain a voltage integral value of the area before the mutation and a voltage integral value of the area after the mutation;

[0024] Determine whether the difference between the voltage integral value of the region before the mutation and the voltage integral value of the region after the mutation is greater than a preset threshold,

[0025] If so, it is determined that there is a voltage turn in the target area.

[0026] If not, it is determined that there is no voltage turning in the target area.

[0027] Furthermore, after determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes:

[0028] Determine whether the highest value of the secondary voltage waveform signal in the target area is not less than the preset rated voltage,

[0029] If yes, it is determined that the target abnormal capacitor voltage transformer has a primary side head-to-ground flashover defect.

[0030] If not, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect.

[0031] Furthermore, after determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes:

[0032] When it is determined that the mutation position is located in the positive half-cycle of the secondary voltage waveform signal and the integrated voltage value of the post-mutation region is negative, it is determined that the target abnormal capacitor voltage transformer has a primary-side head-to-ground flashover defect;

[0033] When it is determined that the mutation position is located in the negative half-cycle of the secondary voltage waveform signal, the integral voltage value of the area before the mutation is positive, and the integral voltage value of the area after the mutation is positive, it is determined that the target abnormal capacitive voltage transformer has a primary side head-to-ground flashover defect.

[0034] Furthermore, after determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes:

[0035] When it is determined that the mutation position is located in the positive half-cycle of the secondary voltage waveform signal and the integrated voltage value of the post-mutation region is positive, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect;

[0036] When it is determined that the mutation position is located in the negative half-cycle of the secondary voltage waveform signal, the integral voltage value of the area before the mutation is negative, and the integral voltage value of the area after the mutation is negative, it is determined that the target abnormal capacitive voltage transformer has a primary side head end open circuit defect.

[0037] An embodiment of the present invention further provides a primary side defect detection device for a capacitor voltage transformer, comprising: a secondary voltage waveform signal acquisition module, a target abnormal capacitor voltage transformer determination module, and a primary side defect detection module;

[0038] The secondary voltage waveform signal acquisition module is used to acquire the secondary voltage waveform signal of the capacitor voltage transformer in the target substation;

[0039] The target abnormal capacitor voltage transformer determination module is used to detect the waveform amplitude change of the secondary voltage waveform signal, and screen out the target abnormal capacitor voltage transformer with a sudden change in voltage waveform based on the waveform amplitude change;

[0040] The primary side defect detection module is used to locate the target area where the secondary voltage waveform signal of the target abnormal capacitor voltage transformer has a sudden change in voltage waveform, and determine whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area.

[0041] If so, it is determined that the target abnormal capacitor voltage transformer has a primary side defect,

[0042] If not, it is determined that the target abnormal capacitor voltage transformer has no primary side defect.

[0043] The present application also provides a terminal device, including:

[0044] one or more processors;

[0045] a memory, coupled to the processor, for storing one or more programs;

[0046] When the one or more programs are executed by the one or more processors, the one or more processors implement the primary side defect detection method of the capacitor voltage transformer as described in the above-mentioned embodiment of the invention.

[0047] The following beneficial effects are achieved by implementing the present invention:

[0048] The present invention provides a primary-side defect detection method, device and terminal equipment for a capacitor voltage transformer. The method determines whether there is a target abnormal capacitor voltage transformer with a sudden change in voltage waveform by identifying the waveform amplitude change of the secondary voltage waveform signal of the capacitor voltage transformer. Further, by analyzing whether a voltage reversal phenomenon occurs in the target area where the voltage waveform of the target abnormal capacitor voltage transformer occurs, it is determined whether the target abnormal capacitor voltage transformer has a primary-side defect. Thus, the gap in the prior art in the identification of primary-side defects of capacitor voltage transformers is filled, and the occurrence of erosion and decreased sealing of the capacitor voltage transformer due to long-term operation with defects and repeated arcing at the grounding point is avoided, thereby improving the safety and stability of the operation of the capacitor voltage transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0050] Figure 1 This is a flow chart of a method for detecting defects on the primary side of a capacitor voltage transformer provided in one embodiment of the present application;

[0051] Figure 2 This is a schematic diagram of a capacitor voltage transformer provided by a certain embodiment of the present application having a primary head-to-ground flashover defect;

[0052] Figure 3 This is a recorded waveform when a capacitor voltage transformer provided by a certain embodiment of the present application has a primary head-to-ground flashover defect;

[0053] Figure 4 This is a simulation waveform when a capacitor voltage transformer provided by a certain embodiment of the present application has a primary head-to-ground flashover defect;

[0054] Figure 5 This is a simulation waveform when a capacitor voltage transformer provided by a certain embodiment of the present application has a primary head-end open circuit defect;

[0055] Figure 6 This is a structural diagram of a primary side defect detection device for a capacitor voltage transformer provided in one embodiment of the present application;

[0056] Figure 7 This is a schematic diagram of the structure of a terminal device provided in a certain embodiment of the present application. DETAILED DESCRIPTION

[0057] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying 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 making any creative efforts are within the scope of protection of this application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0059] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0060] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0062] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0063] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0064] Example 1

[0065] See also Figure 1 To solve the problem that the existing technology cannot identify defects on the primary side of a CVT electromagnetic unit, an embodiment of the present invention provides a method for detecting defects on the primary side of a capacitor voltage transformer, comprising:

[0066] S1, collecting the secondary voltage waveform signal of the capacitor voltage transformer in the target substation;

[0067] In a preferred embodiment, collecting the secondary voltage waveform signal of the capacitor voltage transformer in the target substation includes:

[0068] Determine the preset sampling frequency;

[0069] collecting secondary voltage waveform signals of each capacitor voltage transformer in the target substation according to the sampling frequency;

[0070] Schematically, the secondary voltage waveform signals of each capacitor voltage transformer in the target substation are detected and collected in real time;

[0071] Specifically, each of the capacitive voltage transformers is installed at different busbars, different outgoing lines, etc.;

[0072] Preferably, the sampling frequency can be set to 5 MHz.

[0073] S2. Detecting a change in the waveform amplitude of the secondary voltage waveform signal, and screening target abnormal capacitor voltage transformers with voltage waveform mutations based on the change in the waveform amplitude;

[0074] In a preferred embodiment, detecting the change in the waveform amplitude of the secondary voltage waveform signal and screening out target abnormal capacitor voltage transformers having voltage waveform mutations based on the change in the waveform amplitude includes:

[0075] Obtaining a preset sampling point interval and a preset amplitude change threshold;

[0076] For each of the capacitor voltage transformers, traversing the secondary voltage waveform signal of the capacitor voltage transformer using the sampling point interval, and upon detecting that a waveform amplitude change of the secondary voltage waveform signal within the sampling point interval exceeds the amplitude change threshold, determining that the capacitor voltage transformer has a voltage waveform mutation, and identifying the capacitor voltage transformer as an abnormal capacitor voltage transformer;

[0077] For each abnormal capacitor voltage transformer, locate the installation location of the abnormal capacitor voltage transformer, and when it is detected that the capacitor voltage transformer with a sudden change in voltage waveform at the installation location is only the abnormal capacitor voltage transformer, use the abnormal capacitor voltage transformer as the target abnormal capacitor voltage transformer;

[0078] Schematically, it is necessary to analyze whether the secondary voltage waveform signal has a voltage waveform mutation. In order to better illustrate this application, the following explanation is given by taking a certain capacitor voltage transformer in the target substation as an example:

[0079] Specifically, first, before analyzing the secondary voltage waveform signal, it is necessary to determine a suitable sampling point interval; for example, it can be set to take a sampling point every 0.1 seconds, and 10 sampling points can be taken continuously to form a sampling point interval;

[0080] Similarly, an amplitude change threshold is set in advance according to actual conditions such as the range of voltage waveform amplitude fluctuation during normal operation of the capacitor voltage transformer. For example, the amplitude change threshold is set to 2V.

[0081] Then, according to the predetermined sampling point intervals, the secondary voltage waveform signal output by the capacitor voltage transformer is detected in sequence, that is, starting from the beginning of the secondary voltage waveform signal, after the analysis of the first sampling point interval is completed, moving to the next adjacent sampling point interval to continue the analysis, and repeating this process until the traversal is completed;

[0082] During the traversal process, when it is monitored that the waveform amplitude change of the secondary voltage waveform signal within the sampling point interval exceeds the amplitude change threshold, it is determined that the capacitor voltage transformer has a voltage waveform mutation and is no longer in a normal and stable state. Therefore, the capacitor voltage transformer is regarded as an abnormal capacitor voltage transformer.

[0083] Indicatively, since a sudden change in the voltage waveform may also be caused by an external problem in the system, determining whether there is a defect on the primary side of the capacitor voltage transformer based solely on the sudden change in the voltage waveform may result in a misjudgment. Therefore, in order to improve the accuracy of the detection, further identification is required.

[0084] Specifically, the abnormal capacitor voltage transformer is located at the installation location, and it is detected whether there is only one capacitor voltage transformer with a sudden change in voltage waveform at the installation location, that is, the abnormal capacitor voltage transformer. If so, it is considered that the sudden change in voltage waveform of the abnormal capacitor voltage transformer is caused by its own defects or abnormal operating state. Therefore, the abnormal capacitor voltage transformer is used as the target abnormal capacitor voltage transformer;

[0085] It should be noted that the sampling point interval can be set according to actual conditions; the amplitude change threshold can also be set according to actual conditions. In this application, the amplitude change threshold is set to 2V.

[0086] S3, locating the target area where the secondary voltage waveform signal of the target abnormal capacitor voltage transformer appears a sudden change in voltage waveform, and judging whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area,

[0087] If so, it is determined that the target abnormal capacitor voltage transformer has a primary side defect,

[0088] If not, it is determined that the target abnormal capacitor voltage transformer does not have a primary side defect;

[0089] In a preferred embodiment, the locating the target area where the secondary voltage waveform signal of the target abnormal capacitor voltage transformer has a sudden voltage waveform change includes:

[0090] Obtaining a preset judgment cycle window;

[0091] Locating a mutation position where a voltage waveform mutation occurs in the target abnormal capacitor voltage transformer;

[0092] Taking the mutation position as a starting point, the target area of the target abnormal capacitor voltage transformer is selected using the judgment period window; wherein the target area includes the mutation position, the area before the mutation, and the area after the mutation;

[0093] Indicatively, a discrimination cycle window needs to be set, and the discrimination cycle window can frame a portion of the secondary voltage waveform signal including the mutation position, thereby improving the fault detection accuracy;

[0094] Specifically, the size of the discrimination period window is determined by taking the mutation position as the starting point, the 1 / 4 cycle before the mutation position as the left boundary of the discrimination period window, and the 1 / 4 cycle after the mutation position as the right boundary of the discrimination period window to determine the size of the discrimination period window;

[0095] It should be noted that the 1 / 4 cycle here is not fixed and can be dynamically adjusted according to actual needs;

[0096] Specifically, after determining the discrimination period window, a target area of the target abnormal capacitor voltage transformer is obtained by frame selection.

[0097] In a preferred embodiment, judging whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area includes:

[0098] Integrating the sampled voltage values of the secondary voltage waveform signal in the target area to obtain a voltage integral value of the area before the mutation and a voltage integral value of the area after the mutation;

[0099] Determine whether the difference between the voltage integral value of the region before the mutation and the voltage integral value of the region after the mutation is greater than a preset threshold,

[0100] If so, it is determined that there is a voltage turn in the target area.

[0101] If not, determining that there is no voltage steering in the target area;

[0102] Schematically, the voltage integral value of the region before the mutation and the voltage integral value of the region after the mutation in the target region are calculated respectively, and then it is determined whether the difference between the voltage integral value of the region before the mutation and the voltage integral value of the region after the mutation is significant, thereby determining whether voltage steering has occurred;

[0103] Specifically, if the difference between the voltage integral value of the area before the mutation and the voltage integral value of the area after the mutation is greater than a preset threshold, it is determined that there is a voltage turn in the target area, or it is determined whether the voltage integral value of the area before the mutation and the voltage integral value of the area after the mutation have opposite signs. If so, it is determined that there is a voltage turn in the target area.

[0104] See also Figure 2 In a preferred embodiment, after determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes:

[0105] Determine whether the highest value of the secondary voltage waveform signal in the target area is not less than the preset rated voltage,

[0106] If yes, it is determined that the target abnormal capacitor voltage transformer has a primary side head-to-ground flashover defect.

[0107] If not, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect;

[0108] Schematically, a flashover defect at the head end of a CVT electromagnetic unit may cause an overvoltage with a relatively high amplitude, which can reach more than twice the rated operating voltage through simulation and actual measurement. This is significantly different from an open circuit defect at the primary end of a CVT electromagnetic unit. That is, although both a flashover defect at the primary end to ground and an open circuit defect at the primary end may cause the amplitude of the secondary voltage waveform signal of the target abnormal capacitor voltage transformer to exceed the normal operating voltage, the overvoltage level of the open circuit defect at the primary end is generally lower. Therefore, the present application utilizes this feature to further identify the type of defect at the primary side of a CVT electromagnetic unit.

[0109] Specifically, analyze whether the maximum value of the secondary voltage waveform signal of the target abnormal capacitor voltage transformer is not less than 1.4 times the rated voltage. If so, it is determined that the target abnormal capacitor voltage transformer has a primary side head end flashover defect to ground; otherwise, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect.

[0110] In a preferred embodiment, after determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes:

[0111] When it is determined that the mutation position is located in the positive half-cycle of the secondary voltage waveform signal and the integrated voltage value of the post-mutation region is negative, it is determined that the target abnormal capacitor voltage transformer has a primary-side head-to-ground flashover defect;

[0112] When it is determined that the mutation position is located at the negative half-cycle of the secondary voltage waveform signal, the integrated voltage value of the region before the mutation is positive, and the integrated voltage value of the region after the mutation is positive, it is determined that the target abnormal capacitor voltage transformer has a primary-side head-to-ground flashover defect;

[0113] Schematically, the primary side defect includes a primary side head end to ground flashover defect and a primary side head end open circuit defect. In order to gain a deeper understanding of the fault condition of the target abnormal capacitor voltage transformer, the secondary voltage waveform signal of the target abnormal capacitor voltage transformer is further analyzed to improve the fault identification accuracy.

[0114] Specifically, Figure 3 This is the waveform recorded when a capacitor voltage transformer has a primary head-to-ground flashover defect; Figure 4 This is the simulation waveform when the capacitor voltage transformer has a flashover defect from the first end to the ground; Figure 3 and Figure 4It can be seen that the flashover defect of the electromagnetic unit of the capacitor voltage transformer from the primary terminal to the ground will cause a significant distortion of the voltage waveform, which is characterized by periodic mutations. The waveform before and after the mutation is quite different. This is because the flashover is composed of periodic disconnection and conduction. The conduction process causes the electromagnetic unit to charge. Therefore, the distortion of the waveform before and after the conduction can be used as the identification condition of the primary terminal flashover defect from the primary terminal to the ground.

[0115] In a preferred embodiment, after determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes:

[0116] When it is determined that the mutation position is located in the positive half-cycle of the secondary voltage waveform signal and the integrated voltage value of the post-mutation region is positive, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect;

[0117] When it is determined that the mutation position is located in the negative half-cycle of the secondary voltage waveform signal, the integrated voltage value of the region before the mutation is negative, and the integrated voltage value of the region after the mutation is negative, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect;

[0118] Specifically, Figure 5 This is the simulation waveform when the capacitor voltage transformer has a primary open circuit defect; Figure 5 It can be seen that the open-circuit defect at the primary end of the electromagnetic unit of the capacitor voltage transformer can also cause a significant distortion of the voltage waveform, characterized by periodic mutations. The waveforms before and after the mutations are quite different. This is because flashover consists of periodic disconnection and conduction. The conduction process causes the electromagnetic unit to charge, and the disconnection process causes it to discharge slowly. Therefore, the distortion of the waveform before and after the conduction can be used as the identification condition for the open-circuit defect at the primary end.

[0119] Example 2

[0120] See Figure 6 , is a primary side defect detection device for a capacitor voltage transformer provided by an embodiment of the present invention, comprising: a secondary voltage waveform signal acquisition module, a target abnormal capacitor voltage transformer determination module, and a primary side defect detection module;

[0121] The secondary voltage waveform signal acquisition module is used to acquire the secondary voltage waveform signal of the capacitor voltage transformer in the target substation;

[0122] The target abnormal capacitor voltage transformer determination module is used to detect the waveform amplitude change of the secondary voltage waveform signal, and screen out the target abnormal capacitor voltage transformer with a sudden change in voltage waveform based on the waveform amplitude change;

[0123] The primary side defect detection module is used to locate the target area where the secondary voltage waveform signal of the target abnormal capacitor voltage transformer has a sudden change in voltage waveform, and determine whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area.

[0124] If so, it is determined that the target abnormal capacitor voltage transformer has a primary side defect,

[0125] If not, it is determined that the target abnormal capacitor voltage transformer has no primary side defect.

[0126] Example 3

[0127] See also Figure 7 , an embodiment of the present application further provides a terminal device, including:

[0128] one or more processors;

[0129] a memory, coupled to the processor, for storing one or more programs;

[0130] When the one or more programs are executed by the one or more processors, the one or more processors implement the primary side defect detection method of the capacitor voltage transformer as described above.

[0131] The processor is used to control the overall operation of the terminal device to complete all or part of the steps of the primary side defect detection method of the capacitor voltage transformer described above. The memory is used to store various types of data to support the operation of the terminal device. For example, these data may include instructions for any application or method used to operate on the terminal device, as well as application-related data. The memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0132] In an exemplary embodiment, the terminal device can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to execute the primary side defect detection method of a capacitor voltage transformer as described in any of the above embodiments, and achieve the same technical effect as the above method.

[0133] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for detecting defects on the primary side of a capacitor voltage transformer, characterized in that: include: Collect the secondary voltage waveform signal of the capacitor voltage transformer in the target substation; detecting a change in the waveform amplitude of the secondary voltage waveform signal, and screening out target abnormal capacitor voltage transformers having a sudden change in voltage waveform based on the change in the waveform amplitude; Locating a target area where a voltage waveform mutation occurs in the secondary voltage waveform signal of the target abnormal capacitor voltage transformer, and determining whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area, If so, it is determined that the target abnormal capacitor voltage transformer has a primary side defect, If not, it is determined that the target abnormal capacitor voltage transformer has no primary side defect.

2. The primary side defect detection method of a capacitor voltage transformer according to claim 1, characterized in that: The collecting of the secondary voltage waveform signal of the capacitor voltage transformer in the target substation includes: Determine the preset sampling frequency; The secondary voltage waveform signal of each capacitor voltage transformer in the target substation is collected according to the sampling frequency.

3. The primary side defect detection method of a capacitor voltage transformer according to claim 1, characterized in that: The detecting the waveform amplitude change of the secondary voltage waveform signal and screening out target abnormal capacitor voltage transformers having voltage waveform mutations according to the waveform amplitude change includes: Obtaining a preset sampling point interval and a preset amplitude change threshold; For each of the capacitor voltage transformers, traversing the secondary voltage waveform signal of the capacitor voltage transformer using the sampling point interval, and upon detecting that a waveform amplitude change of the secondary voltage waveform signal within the sampling point interval exceeds the amplitude change threshold, determining that the capacitor voltage transformer has a voltage waveform mutation, and identifying the capacitor voltage transformer as an abnormal capacitor voltage transformer; For each abnormal capacitor voltage transformer, the installation position of the abnormal capacitor voltage transformer is located, and when it is detected that the capacitor voltage transformer with a sudden change in voltage waveform at the installation position is only the abnormal capacitor voltage transformer, the abnormal capacitor voltage transformer is used as the target abnormal capacitor voltage transformer.

4. The primary side defect detection method of a capacitor voltage transformer according to claim 1, characterized in that: The target area where the secondary voltage waveform signal of the target abnormal capacitor voltage transformer has a sudden change in voltage waveform is located includes: Obtaining a preset judgment cycle window; Locating a mutation position where a voltage waveform mutation occurs in the target abnormal capacitor voltage transformer; Taking the mutation position as a starting point, the target area of the target abnormal capacitor voltage transformer is selected using the judgment period window frame; wherein, the target area includes the mutation position, the pre-mutation area and the post-mutation area.

5. The primary side defect detection method of a capacitor voltage transformer according to claim 4, characterized in that: The determining, based on the secondary voltage waveform signal in the target area, whether there is a voltage reversal in the target area includes: Integrating the sampled voltage values of the secondary voltage waveform signal in the target area to obtain a voltage integral value of the area before the mutation and a voltage integral value of the area after the mutation; Determine whether the difference between the voltage integral value of the region before the mutation and the voltage integral value of the region after the mutation is greater than a preset threshold, If so, it is determined that there is a voltage turn in the target area. If not, it is determined that there is no voltage turning in the target area.

6. The primary side defect detection method of a capacitor voltage transformer according to claim 5, characterized in that: After determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes: Determine whether the highest value of the secondary voltage waveform signal in the target area is not less than the preset rated voltage, If yes, it is determined that the target abnormal capacitor voltage transformer has a primary side head-to-ground flashover defect. If not, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect.

7. The method for detecting defects on the primary side of a capacitor voltage transformer according to claim 5, wherein: After determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes: When it is determined that the mutation position is located in the positive half-cycle of the secondary voltage waveform signal and the integrated voltage value of the post-mutation region is negative, it is determined that the target abnormal capacitor voltage transformer has a primary-side head-to-ground flashover defect; When it is determined that the mutation position is located in the negative half-cycle of the secondary voltage waveform signal, the integral voltage value of the area before the mutation is positive, and the integral voltage value of the area after the mutation is positive, it is determined that the target abnormal capacitive voltage transformer has a primary side head-to-ground flashover defect.

8. The method for detecting defects on the primary side of a capacitor voltage transformer according to claim 5, wherein: After determining that the target abnormal capacitor voltage transformer has a primary side defect, the method further includes: When it is determined that the mutation position is located in the positive half cycle of the secondary voltage waveform signal and the integrated voltage value of the post-mutation region is positive, it is determined that the target abnormal capacitor voltage transformer has a primary side head end open circuit defect; When it is determined that the mutation position is located in the negative half-cycle of the secondary voltage waveform signal, the integral voltage value of the area before the mutation is negative, and the integral voltage value of the area after the mutation is negative, it is determined that the target abnormal capacitive voltage transformer has a primary side head end open circuit defect.

9. A primary side defect detection device for a capacitor voltage transformer, characterized in that: include: Secondary voltage waveform signal acquisition module, target abnormal capacitor voltage transformer determination module and primary side defect detection module; The secondary voltage waveform signal acquisition module is used to acquire the secondary voltage waveform signal of the capacitor voltage transformer in the target substation; The target abnormal capacitor voltage transformer determination module is used to detect the waveform amplitude change of the secondary voltage waveform signal, and screen out the target abnormal capacitor voltage transformer with a sudden change in voltage waveform based on the waveform amplitude change; The primary side defect detection module is used to locate the target area where the secondary voltage waveform signal of the target abnormal capacitor voltage transformer has a sudden change in voltage waveform, and determine whether there is a voltage reversal in the target area based on the secondary voltage waveform signal in the target area. If so, it is determined that the target abnormal capacitor voltage transformer has a primary side defect, If not, it is determined that the target abnormal capacitor voltage transformer has no primary side defect.

10. A terminal device, characterized in that: include: one or more processors; a memory, coupled to the processor, for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the primary side defect detection method of the capacitor voltage transformer according to any one of claims 1 to 8.

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