Metal particle defect diagnosis method under alternating current superposition impact

Abstract

The invention relates to a metal particle defect diagnosis method, system, medium and equipment under alternating current superposition impact, in the method, alternating current superposition impact voltage is applied to a GIS for partial discharge, n groups of original waveform data are obtained through measurement, and the original waveform data comprise discharge time data, discharge current value data, discharge capacity data and a PRPD spectrogram; extracting and calculating characteristic values of partial discharge in the original data waveform, wherein the characteristic values comprise a discharge capacity maximum value x, average discharge delay time delta t between an impact applying moment and a partial discharge starting moment, and a partial discharge PRPD spectrogram; performing metal particle defect diagnosis according to the maximum value x of the average discharge capacity; and diagnosing the number of the GIS metal particles according to the average discharge delay time delta t and the PRPD spectrogram envelope, and judging the defect type of the metal particles.

Description

Technical Field

[0001] The present invention relates to the technical field of GIS metal particle diagnosis, and in particular to a metal particle defect diagnosis method, system, medium and equipment under AC superimposed impact. Background Art

[0002] In recent years, with the rapid development of urbanization and the large-scale construction of high-voltage power grids, power accidents caused by gas-insulated switch-gear (GIS) failures have also increased, directly affecting the safety of energy transmission channels and the stability of the entire power grid system. Insulation defects account for the highest proportion of major GIS failures.

[0003] Although GIS equipment has a reliable packaging structure, insulation failures caused by free metal particle defects have occurred many times during its field operation. Free metal particle defects will cause the insulation strength of SF6 to decrease by more than 80%, seriously threatening the operation safety of GIS. At present, there are few ways to detect GIS metal particles. The problems are that the detection accuracy is low and the GIS fault information cannot be accurately detected. Secondly, the fault type of GIS metal particle defects cannot be accurately determined. The metal defect types of GIS include spherical metal particles, linear metal particles, etc., and the number is uncertain.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0005] The present invention provides a method, system, medium and equipment for diagnosing metal particle defects under AC superimposed impact, which solves the problems of inaccurate detection and failure to detect specific metal defect types when diagnosing GIS metal particles.

[0006] A method for diagnosing metal particle defects under AC superposition shock includes:

[0007] Step S1: applying an AC superimposed impulse voltage to the GIS to locally discharge, and measuring and obtaining n groups of original waveform data, wherein the original waveform data includes discharge time data, discharge current value data, discharge amount data and PRPD spectrum;

[0008] Step S2: extracting and calculating characteristic values ​​of partial discharge in the original data waveform, the characteristic values ​​include the maximum discharge value x, the average discharge hysteresis time △t between the impulse application time and the partial discharge start time, and the partial discharge PRPD spectrum;

[0009] Step S3: diagnose metal particle defects according to the maximum value x of the average discharge amount;

[0010] Step S4: diagnose the number of GIS metal particles from the average discharge delay time △t and the PRPD spectrum envelope to determine the type of metal particle defects.

[0011] In the metal particle defect diagnosis method under AC superposition impulse, in step S1, a high-frequency pulse current sensor and a partial discharge detector are used to measure the partial discharge of GIS under AC superposition impulse voltage to obtain n groups of original waveform data.

[0012] In the metal particle defect diagnosis method under AC superposition impulse, the AC superposition impulse voltage is superimposed on the AC voltage at a phase of 270°.

[0013] In the metal particle defect diagnosis method under AC superposition impact, in step S2, the formula for calculating the average discharge maximum value x and the average discharge hysteresis time △t is as follows:

[0014] Where Δt i is the average time interval corresponding to the i-th group of original waveform data,

[0015] where x i is the maximum discharge value corresponding to the i-th group of original waveform data.

[0016] In the metal particle defect diagnosis method under AC superposition shock, in step S2, the characteristic value of the partial discharge signal corresponding to each group of original waveform data is extracted as follows:

[0017] The discharge hysteresis time Δt is extracted by first obtaining the impulse application time and the partial discharge start time, and then taking the difference between the two times. This time interval is the discharge hysteresis time Δt under a single impulse.

[0018] The maximum discharge capacity x is extracted in the following way: firstly, the discharge capacity under m discharge cycles is obtained, and then the maximum value of the discharge capacity under m discharge cycles is counted, and the maximum value is the maximum value x of the single impact discharge capacity;

[0019] The PRPD spectrum extraction method is as follows: firstly, the discharge amplitude and the power frequency voltage phase angle under m discharge cycles are obtained, and then the PRPD spectrum is derived from the partial discharge detector.

[0020] In the metal particle defect diagnosis method under AC superposition impact, in step s3, if the average discharge maximum value x is greater than 500pc, it is considered that linear metal particles exist. By observing the envelope of the partial discharge PRPD spectrum, if the number of discharge points outside the envelope is greater than 10, it is considered that multiple linear metal particles exist, otherwise a single linear metal particle exists.

[0021] A metal particle defect diagnosis system under AC superposition shock includes:

[0022] A measuring unit, which is used to apply an AC superimposed impulse voltage to the GIS to locally discharge, and measure and obtain n groups of original waveform data, wherein the original waveform data includes discharge time data, discharge current value data, discharge amount data and PRPD spectrum;

[0023] A pulse sequence generating unit, which is used to generate a partial discharge pulse sequence under an AC superimposed impulse voltage based on each group of original data waveforms;

[0024] An extraction unit, which is used to extract and calculate the characteristic values ​​of partial discharge in the original data waveform, the characteristic values ​​including the maximum discharge value x, the average discharge hysteresis time △t between the impulse application time and the partial discharge start time, and the partial discharge PRPD spectrum;

[0025] A diagnosis unit, which is used to diagnose metal particle defects according to the maximum value x of the average discharge amount;

[0026] The judgment unit is used to diagnose the number of GIS metal particles from the average discharge delay time △t and the PRPD spectrum envelope, and judge the type of metal particle defects.

[0027] A computer storage medium includes computer instructions, which, when executed on a computer, cause the computer to execute the method described.

[0028] An electronic device, comprising:

[0029] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0030] When the processor executes the program, the method described is implemented.

[0031] Compared with the prior art, the present invention has the following advantages: the present invention obtains n groups of original waveform data of GIS by superimposing AC impulse voltage, then extracts and calculates the characteristic values ​​of local discharge in the original data waveform, and finally diagnoses metal particle defects according to the determined conditions through different characteristic values, thereby detecting the type of metal particle defects of GIS on the basis of accurately detecting GIS faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0033] In the attached picture:

[0034] Figure 1 It is a flowchart of a method for diagnosing metal particle defects under AC superimposed impact provided by an embodiment of the present disclosure.

[0035] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0037] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0038] To facilitate understanding of the embodiments of the present invention, further explanation will be given below by taking specific embodiments as examples in conjunction with the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0039] like Figure 1 As shown, the metal particle defect diagnosis method under AC superposition shock includes the following steps:

[0040] Step S1: applying an AC superimposed impulse voltage to the GIS to locally discharge, and measuring and obtaining n groups of original waveform data, wherein the original waveform data includes discharge time data, discharge current value data, discharge amount data and PRPD spectrum;

[0041] Step S2: extracting and calculating characteristic values ​​of partial discharge in the original data waveform, the characteristic values ​​include the maximum discharge value x, the average discharge hysteresis time △t between the impulse application time and the partial discharge start time, and the partial discharge PRPD spectrum;

[0042] Step S3: diagnose metal particle defects according to the maximum value x of the average discharge amount;

[0043] Step S4: diagnose the number of GIS metal particles from the average discharge delay time △t and the PRPD spectrum envelope to determine the type of metal particle defects.

[0044] In the preferred implementation of the metal particle defect diagnosis method under AC superimposed impulse, in step S1, a high-frequency pulse current sensor and a partial discharge detector are used to measure the partial discharge of GIS under AC superimposed impulse voltage to obtain n groups of original waveform data.

[0045] In a preferred implementation of the metal particle defect diagnosis method under AC superimposed impulse, the AC superimposed impulse voltage is superimposed on the AC voltage at a phase of 270°.

[0046] In the preferred implementation of the metal particle defect diagnosis method under AC superposition impact, in step S2, the formula for calculating the average discharge maximum value x and the average discharge hysteresis time △t is as follows:

[0047] Where Δt i is the average time interval corresponding to the i-th group of original waveform data,

[0048] where x i is the maximum discharge value corresponding to the i-th group of original waveform data.

[0049] In the preferred implementation of the metal particle defect diagnosis method under AC superposition impact, in step S2, the characteristic value of the partial discharge signal corresponding to each group of original waveform data is extracted as follows:

[0050] The discharge hysteresis time Δt is extracted by first obtaining the impulse application time and the partial discharge start time, and then taking the difference between the two times. This time interval is the discharge hysteresis time Δt under a single impulse.

[0051] The maximum discharge capacity x is extracted in the following way: firstly, the discharge capacity under m discharge cycles is obtained, and then the maximum value of the discharge capacity under m discharge cycles is counted, and the maximum value is the maximum value x of the single impact discharge capacity;

[0052] The PRPD spectrum extraction method is as follows: firstly, the discharge amplitude and the power frequency voltage phase angle under m discharge cycles are obtained, and then the PRPD spectrum is derived from the partial discharge detector.

[0053] In a preferred implementation of the metal particle defect diagnosis method under AC superposition impact, in step S3, if the average discharge maximum value x is greater than 500pc, it is considered that linear metal particles exist. By observing the envelope of the partial discharge PRPD spectrum, if the number of discharge points outside the envelope is greater than 10, it is considered that multiple linear metal particles exist, otherwise a single linear metal particle exists.

[0054] A metal particle defect diagnosis system under AC superposition shock includes:

[0055] A measuring unit, which is used to apply an AC superimposed impulse voltage to the GIS to locally discharge, and measure and obtain n groups of original waveform data, wherein the original waveform data includes discharge time data, discharge current value data, discharge amount data and PRPD spectrum;

[0056] A pulse sequence generating unit, which is used to generate a partial discharge pulse sequence under an AC superimposed impulse voltage based on each group of original data waveforms;

[0057] An extraction unit, which is used to extract and calculate the characteristic values ​​of partial discharge in the original data waveform, the characteristic values ​​including the maximum discharge value x, the average discharge hysteresis time △t between the impulse application time and the partial discharge start time, and the partial discharge PRPD spectrum;

[0058] A diagnosis unit, which is used to diagnose metal particle defects according to the maximum value x of the average discharge amount;

[0059] The judgment unit is used to diagnose the number of GIS metal particles from the average discharge delay time △t and the PRPD spectrum envelope, and judge the type of metal particle defects.

[0060] A computer storage medium includes computer instructions, which, when executed on a computer, cause the computer to execute the method described.

[0061] An electronic device, comprising:

[0062] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0063] When the processor executes the program, the method described is implemented.

[0064] In one embodiment, Figure 1 As shown, a method for diagnosing metal particle defects under AC superposition shock includes the following steps:

[0065] S1: Measure the GIS by superimposing AC impulse voltage to obtain n groups of original waveform data.

[0066] Specifically, in this embodiment, in step S1, the high-frequency pulse current sensor and the partial discharge detector respectively measure the partial discharge of the GIS under the AC superimposed impulse voltage (superimposed under the AC voltage phase of 270° by default) to obtain the original waveform data.

[0067] In actual use, the pulse current method is used to continuously collect local discharge data within 180 seconds for statistical processing. Since the movement of particles and local discharge are both random, each group of tests is repeated multiple times to reduce experimental errors.

[0068] In actual use, the value of n is set according to actual needs and is not shown here. Exemplary n can be 5, 10, 15 or other values. When the value of n is larger, the reliability of the data obtained in the following steps is higher.

[0069] Wherein, for the original waveform data in step S1, the original waveform data includes discharge time data and discharge current value data;

[0070] S2: Extract and calculate the characteristic values ​​of partial discharge in the original data waveform, including the maximum discharge value x, the average discharge hysteresis time △t between the impulse application time and the partial discharge start time, and the partial discharge PRPD spectrum.

[0071] Specifically, in this embodiment, the method of extracting the characteristic value of the partial discharge signal corresponding to each group of original waveform data in step S2 is as follows:

[0072] First, m discharge cycles are selected from the partial discharge signal pulse sequence corresponding to each set of original waveform data, where m is a positive integer, and an exemplary m is 50;

[0073] For the discharge hysteresis time Δt, the extraction method is: first obtain the impact application time and the partial discharge start time, and then take the difference between the two times. This time interval is the discharge hysteresis time Δt under a single impact;

[0074] For the maximum discharge amount x, the extraction method is: first obtain the discharge amount under m discharge cycles, and then count the maximum value of the discharge amount in m discharge cycles, which is the maximum value x of the single impact discharge amount;

[0075] For the PRPD spectrum, the extraction method is: first obtain the discharge amplitude and power frequency voltage phase angle under m discharge cycles, and derive the PRPD spectrum from the partial discharge detector.

[0076] The formula for calculating the average maximum discharge capacity x and the average discharge hysteresis time △t is as follows:

[0077]

[0078] Where Δt i is the average time interval corresponding to the i-th group of original waveform data.

[0079]

[0080] where x i is the maximum discharge value corresponding to the i-th group of original waveform data.

[0081] Taking the calculation of the maximum discharge amount as an example, let n be 5 and m be 50. For each set of original waveform data, first obtain the maximum discharge amplitude in 50 discharge cycles respectively, and then find the maximum value of the maximum discharge amplitude in 50 discharge cycles. This maximum value is the maximum discharge amplitude of the local discharge signal pulse sequence corresponding to each set of original waveforms. The maximum discharge amounts of the local discharge signal pulse sequences corresponding to the five sets of original waveform data are x1, x2, x3, x4 and x5:

[0082] At this time, by substituting x1, x2, x3, x4 and x5 into the above formula, the average value of the corresponding maximum discharge value can be obtained.

[0083] S3: Perform metal particle diagnosis on some of the determined conditions according to the average discharge maximum value x.

[0084] Specifically, in this embodiment, if the maximum value x of the average discharge amount is greater than 500pc, it is considered that linear metal particles exist. Further, through the envelope of the partial discharge PRPD spectrum, the number of discharge points outside the envelope is recorded as m. If m is greater than 10, it is considered that multiple linear metal particles exist, otherwise a single linear metal particle exists.

[0085] S4: Diagnose the number of GIS metal particles from the average discharge delay time △t and the PRPD spectrum envelope to determine the type of metal particle defects.

[0086] Specifically, in this embodiment, when the average maximum discharge value x is less than 500pc, it is necessary to judge by the average discharge hysteresis time △t and the PRPD spectrum. △t represents the time interval between the moment of impact application and the moment of partial discharge initiation, because the particles will not immediately have partial discharge in the subsequent AC cycle caused by the impact, but will have self-sustaining discharge after the discharge hysteresis time. The time delay represents the delay in the realization of the partial discharge initiation condition. Since the linear metal particles have two dimensions, diameter and length, when the diameter and length are different but the mass is the same, the average discharge hysteresis time △t of the linear metal particles is almost the same, so only quantitative judgment can be made. The process of diagnosis in step S4 is as follows:

[0087] If m is greater than 10, it is considered that there are multiple metal particles; if m is less than 10, it is considered that there is a single metal particle, and if △t is greater than 690ms, it is considered that there are spherical metal particles. Further analysis shows that if △t is greater than 690ms and less than 710ms, it is considered that there are spherical metal particles of about 1mm; if △t is greater than 710ms and less than 760ms, it is considered that there are spherical metal particles of about 2mm; if △t is greater than 76ms0 and less than 830ms, it is considered that there are spherical metal particles of about 3mm. It should be noted that the comparison thresholds involved in the full text of the present invention, such as 500pc, 690ms, etc., are all empirical values ​​determined based on a large number of experiments.

[0088] In summary, in actual use, the present invention obtains n groups of original waveform data of GIS by superimposing AC impulse voltage, then extracts and calculates the characteristic values ​​of local discharge in the original data waveform, and finally diagnoses metal particle defects according to the determined conditions through different characteristic values, thereby detecting the type of metal particle defects of GIS on the basis of accurately detecting GIS faults.

[0089] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields, and the above specific embodiments are only illustrative and instructive, rather than restrictive. A person of ordinary skill in the art can also make many forms under the guidance of this specification and without departing from the scope of protection of the claims of the present invention, all of which belong to the protection of the present invention.

Claims

1. A method for diagnosing metal particle defects under AC superposition shock, characterized in that: The steps include: Step S1: applying an AC superimposed impulse voltage to the GIS to locally discharge, and measuring and obtaining n groups of original waveform data, wherein the original waveform data includes discharge time data, discharge current value data, discharge amount data and PRPD spectrum; Step S2: extracting and calculating characteristic values ​​of partial discharge in the original data waveform, the characteristic values ​​include the maximum discharge value x, the average discharge hysteresis time △t between the impulse application time and the partial discharge start time, and the partial discharge PRPD spectrum; Step S3: diagnose metal particle defects according to the maximum value x of the average discharge amount; Step S4: diagnose the number of GIS metal particles from the average discharge delay time △t and the PRPD spectrum envelope to determine the type of metal particle defects.

2. The metal particle defect diagnosis method under AC superposition impact according to claim 1 is characterized in that: Preferably, in step S1, a high-frequency pulse current sensor and a partial discharge detector are used to measure partial discharge of GIS under an AC superimposed impulse voltage to obtain n groups of original waveform data.

3. The metal particle defect diagnosis method under AC superposition impact according to claim 1 is characterized in that: The AC superimposed impulse voltage is superimposed on the AC voltage at a phase of 270°.

4. The metal particle defect diagnosis method under AC superposition shock according to claim 1 is characterized in that: In step S2, the formula for calculating the average maximum discharge capacity x and the average discharge hysteresis time △t is as follows: Where Δt i is the average time interval corresponding to the i-th group of original waveform data, where x i is the maximum discharge value corresponding to the i-th group of original waveform data.

5. The metal particle defect diagnosis method under AC superposition impact according to claim 1 is characterized in that: In step S2, the method of extracting the characteristic value of the partial discharge signal corresponding to each set of original waveform data is as follows: The discharge hysteresis time Δt is extracted by first obtaining the impulse application time and the partial discharge start time, and then taking the difference between the two times. This time interval is the discharge hysteresis time Δt under a single impulse. The maximum discharge capacity x is extracted in the following way: firstly, the discharge capacity under m discharge cycles is obtained, and then the maximum value of the discharge capacity under m discharge cycles is counted, and the maximum value is the maximum value x of the single impact discharge capacity; The PRPD spectrum extraction method is as follows: firstly, the discharge amplitude and the power frequency voltage phase angle under m discharge cycles are obtained, and then the PRPD spectrum is derived from the partial discharge detector.

6. The metal particle defect diagnosis method under AC superposition shock according to claim 1 is characterized in that: In step S3, if the average discharge maximum value x is greater than 500pc, it is considered that linear metal particles exist. By observing the envelope of the partial discharge PRPD spectrum, if the number of discharge points outside the envelope is greater than 10, it is considered that multiple linear metal particles exist. Otherwise, a single linear metal particle exists.

7. A metal particle defect diagnosis system under AC superposition impact, characterized in that: These include, A measuring unit, which is used to apply an AC superimposed impulse voltage to the GIS to locally discharge, and measure and obtain n groups of original waveform data, wherein the original waveform data includes discharge time data, discharge current value data, discharge amount data and PRPD spectrum; A pulse sequence generating unit, which is used to generate a partial discharge pulse sequence under an AC superimposed impulse voltage based on each group of original data waveforms; An extraction unit, which is used to extract and calculate the characteristic values ​​of partial discharge in the original data waveform, the characteristic values ​​including the maximum discharge value x, the average discharge hysteresis time △t between the impulse application time and the partial discharge start time, and the partial discharge PRPD spectrum; A diagnostic unit, which is used to diagnose metal particle defects according to the maximum value x of the average discharge amount; The judgment unit is used to diagnose the number of GIS metal particles from the average discharge delay time △t and the PRPD spectrum envelope, and judge the type of metal particle defects.

8. A computer storage medium, characterized in that The storage medium includes computer instructions, which, when executed on a computer, enable the computer to execute the method according to any one of claims 1 to 7.

9. An electronic device, characterized in that: The electronic device comprises: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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