CN114814488A - A method and device for locating UHF partial discharge defects - Google Patents

Abstract

The present application provides a method and device for locating UHF partial discharge defects. The method includes: performing wavelet noise reduction processing on an obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal; The noise signal is subjected to secondary correlation weighting processing to obtain a discharge time delay signal; the location of the UHF partial discharge defect is determined according to the discharge time delay signal. The present application can precisely locate UHF partial discharge defects.

Description

A method and device for locating UHF partial discharge defects

technical field

The present application relates to the field of electrical equipment maintenance, in particular to a method and device for locating UHF partial discharge defects.

Background technique

In recent years, Gas Insulated Switchgear (hereinafter referred to as GIS) has been popularized and applied in power systems, and it is increasingly important to ensure its safe and stable operation. Due to the high internal field strength and small insulation margin of GIS, minor defects are prone to occur in manufacturing, transportation and installation. In the operation of GIS equipment, these tiny defects may cause partial discharge, form discharge channels, deteriorate insulation, and even cause breakdown discharge accidents.

The partial discharge signal generally radiates outward in the form of sound, electricity, light and other waves. The existing technology can realize partial discharge defect location by ultrasonic detection method, UHF detection method and combined sound and electricity detection method. Among them, UHF generally refers to the electromagnetic wave signal of 300MHz-3GHz. Compared with the ultrasonic detection method, the UHF detection method has strong anti-interference performance and extremely high sensitivity, but the UHF detection method is used for partial discharge defect location. The time difference location method is usually used to realize the time difference. Therefore, the accuracy of time delay estimation directly affects the accuracy of fault location. In practical engineering applications, the prior art often directly performs rough time difference comparison on the signals collected by the UHF sensor, but does not perform signal processing before the comparison, resulting in a large fault location error.

SUMMARY OF THE INVENTION

In view of the problems in the prior art, the present application provides a method and device for locating UHF partial discharge defects, which can accurately locate UHF partial discharge defects.

In order to solve the above-mentioned technical problems, the application provides the following technical solutions:

In a first aspect, the present application provides a method for locating UHF partial discharge defects, including:

Perform wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain the corresponding discharge noise reduction signal;

performing secondary correlation weighting processing on the discharge noise reduction signal to obtain a discharge time delay signal;

The location of the UHF partial discharge defect is determined according to the discharge time delay signal.

Further, the method for locating UHF partial discharge defects includes: performing wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal, including:

Wavelet transform is performed on the UHF partial discharge signal by using a wavelet basis to obtain a corresponding wavelet signal;

Perform filtering and noise reduction processing on the wavelet signal to obtain a corresponding filtered signal;

Inverse wavelet transform is performed on the filtered signal to obtain the discharge noise reduction signal.

Further, the method for locating UHF partial discharge defects includes: the discharge noise reduction signal includes: a first discharge noise reduction signal and a second discharge noise reduction signal; Sub-correlation weighting process to obtain the discharge delay signal, including:

performing an autocorrelation operation on the first discharge noise reduction signal to obtain an autocorrelation operation result;

performing a cross-correlation operation on the first discharge noise reduction signal and the second discharge noise reduction signal to obtain a cross-correlation operation result;

Use a generalized weighting function to perform secondary cross-correlation weighting operation on the autocorrelation operation result and the cross-correlation operation result, to obtain a cross-correlation weighting operation result;

Inputting the cross-correlation weighted operation result into a power spectrum function to obtain a corresponding power spectrum;

Inverse fast Fourier transform is performed on the power spectrum to obtain the discharge time delay signal.

Further, the method for locating the UHF partial discharge defect includes: determining the location of the UHF partial discharge defect according to the discharge time delay signal, including:

performing cubic spline interpolation processing on the discharge time delay signal to obtain an interpolation result;

performing delay peak detection on the interpolation result to determine a corresponding delay peak;

The location of the UHF partial discharge defect is determined according to the time delay peak value.

In a second aspect, the present application provides a UHF partial discharge defect locating device, comprising:

A noise reduction processing unit, configured to perform wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal;

a time delay processing unit, configured to perform secondary correlation weighting processing on the discharge noise reduction signal to obtain a discharge time delay signal;

The defect locating unit is configured to determine the location of the UHF partial discharge defect according to the discharge time delay signal.

Further, the noise reduction processing unit includes:

a wavelet transform module, configured to perform wavelet transform on the UHF partial discharge signal by using a wavelet basis to obtain a corresponding wavelet signal;

a filtering module, configured to perform filtering and noise reduction processing on the wavelet signal to obtain a corresponding filtered signal;

A noise reduction module, configured to perform inverse wavelet transform on the filtered signal to obtain the discharge noise reduction signal.

Further, the discharge noise reduction signal includes: a first discharge noise reduction signal and a second discharge noise reduction signal; the delay processing unit includes:

An autocorrelation operation module, configured to perform an autocorrelation operation on the first discharge noise reduction signal to obtain an autocorrelation operation result;

A cross-correlation operation module for performing cross-correlation operation on the first discharge noise reduction signal and the second discharge noise reduction signal to obtain a cross-correlation operation result; The correlation operation result is subjected to a second cross-correlation weighting operation to obtain a cross-correlation weighting operation result;

a power spectrum determination module, configured to input the cross-correlation weighted operation result into a power spectrum function to obtain a corresponding power spectrum;

A delay processing module, configured to perform inverse fast Fourier transform on the power spectrum to obtain the discharge delay signal.

Further, the defect locating unit includes:

an interpolation processing module, configured to perform cubic spline interpolation processing on the discharge delay signal to obtain an interpolation result;

a peak determination module, configured to perform delay peak detection on the interpolation result, and determine a corresponding delay peak;

A defect location module, configured to determine the location of the UHF partial discharge defect according to the time delay peak value.

In a third aspect, the present application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the UHF partial discharge defect when executing the program The steps of the positioning method.

In a fourth aspect, the present application provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements the steps of the UHF partial discharge defect location method.

In view of the problems in the prior art, the method and device for locating UHF partial discharge defects provided by the present application can perform noise reduction processing on the collected UHF partial discharge signal based on wavelet transform, so that the signal is more pure and improves the performance of the signal. Signal-to-noise ratio: perform cross-correlation operation on the UHF partial discharge signal after noise reduction, and then perform a quadratic correlation operation after weighting based on the SCOT function, so that the spectral peaks are more prominent and real under the condition of low signal-to-noise ratio; The cubic spline interpolation operation is performed on the time delay of the cross-correlation operation result, and the time delay result is smoothed, which improves the accuracy of peak value selection. To sum up, the method and device for locating UHF partial discharge defects provided by this application can improve the accuracy of on-site GIS UHF partial discharge defect locating, and provide a reliable basis for on-site defect detection and fault analysis.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a flowchart of a method for locating a UHF partial discharge defect in an embodiment of the application;

2 is a flowchart of generating a discharge noise reduction signal in an embodiment of the application;

3 is a flowchart of generating a discharge delay signal in an embodiment of the application;

FIG. 4 is a flowchart of determining the location of a UHF partial discharge defect in an embodiment of the application;

5 is a structural diagram of a UHF partial discharge defect locating device in an embodiment of the application;

6 is a structural diagram of a noise reduction processing unit in an embodiment of the present application;

FIG. 7 is a structural diagram of a delay processing unit in an embodiment of the present application;

8 is a structural diagram of a defect locating unit in an embodiment of the present application;

FIG. 9 is a schematic structural diagram of an electronic device in an embodiment of the application;

10 is a schematic diagram of generating a discharge noise reduction signal in an embodiment of the application;

11 is a schematic diagram of generating a discharge delay signal in an embodiment of the application;

12 is a schematic diagram of determining the location of a UHF partial discharge defect in an embodiment of the application;

13 is a schematic diagram of the UHF CH1 and CH2 sensors of the isolation switch and the positions of the discharge points in the embodiment of the application;

14 is a schematic diagram of the CH1 and CH2 sensor signals after noise reduction processing in an embodiment of the application;

FIG. 15 is a schematic diagram of a peak signal after interpolation cross-correlation processing in an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In recent years, Gas Insulated Switchgear (hereinafter referred to as GIS) has been popularized and applied in power systems, and it is increasingly important to ensure its safe and stable operation. Due to the high internal field strength and small insulation margin of GIS, minor defects are prone to occur in manufacturing, transportation and installation. In the operation of GIS equipment, these tiny defects may cause partial discharge, form discharge channels, deteriorate insulation, and even cause breakdown discharge accidents.

In one embodiment, referring to FIG. 1 , in order to accurately locate UHF partial discharge defects, the present application provides a method for locating UHF partial discharge defects, including:

S101: Perform wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal;

S102: Perform secondary correlation weighting processing on the discharge noise reduction signal to obtain a discharge time delay signal;

S103: Determine the location of the UHF partial discharge defect according to the discharge delay signal.

It can be understood that the UHF partial discharge defect location method provided by this application can accurately determine the time delay of the UHF partial discharge signal by collecting, processing and valuing the UHF partial discharge signal. It can show good anti-noise ability in a low signal-to-noise ratio environment, and at the same time, it can ensure that accurate time delay estimates can be obtained when the hardware sampling rate of the GIS system in the engineering site is low, so as to achieve accurate positioning of fault signals. .

Further, in the signal acquisition stage, when UHF partial discharge occurs inside the GIS system, the multi-channel UHF sensor can collect the UHF partial discharge signal, which can be transmitted to the delay processing through the cable after wavelet noise reduction processing. unit; after the preliminary denoised UHF partial discharge signal is processed by a quadratic correlation algorithm weighted based on a generalized function (such as SCOT function), the time delay waveform of the signal similarity degree can be obtained and the processed signal can be sent to the defect location unit Perform peak detection; the signal processed by the generalized function uses the cubic spline interpolation method to further fit its peak value, and the final read peak time delay is the signal time difference; according to the signal time difference, it can be calculated and output inside the GIS The location of the partial discharge defect.

It can be seen from the above description that the method for locating UHF partial discharge defects provided by the present application can perform noise reduction processing on the collected UHF partial discharge signal based on wavelet transform, so that the signal is purer and the signal-to-noise ratio is improved; The UHF partial discharge signal after noise reduction is subjected to cross-correlation operation, and then weighted based on the SCOT function to carry out quadratic correlation operation, so that under the condition of low signal-to-noise ratio, the spectral peaks are more prominent and true; The time delay is calculated by cubic spline interpolation, and the time delay result is smoothed, which improves the accuracy of peak value selection. To sum up, the method and device for locating UHF partial discharge defects provided by this application can improve the accuracy of on-site GIS UHF partial discharge defect locating, and provide a reliable basis for on-site defect detection and fault analysis.

In an embodiment, referring to FIG. 2 , the wavelet noise reduction processing is performed on the obtained UHF partial discharge signal to obtain the corresponding discharge noise reduction signal, including:

S201: Use wavelet basis to perform wavelet transformation on the UHF partial discharge signal to obtain a corresponding wavelet signal;

S202: Perform filtering and noise reduction processing on the wavelet signal to obtain a corresponding filtered signal;

S203: Perform inverse wavelet transform on the filtered signal to obtain the discharge noise reduction signal.

It can be understood that, performing wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal can be achieved through steps S201 to S203.

It should be noted that the collected UHF partial discharge signals are often weak and easily interfered by pulsed signals such as electromagnetic wave communication and high-frequency signal protection. The UHF partial discharge signal collected by the sensor is subjected to wavelet noise reduction processing, see Figure 10.

It is divided into three steps:

(1) Wavelet decomposition: In the embodiment of the present application, the wavelet base is selected as "db4", and the original signal is decomposed in three layers to obtain wavelet coefficients. Its function is to make the signal reconstruction process smoother and the localization in the frequency domain better. ;

(2) Threshold value processing: The threshold value is estimated according to the level of noise in the UHF partial discharge signal, the threshold value is selected as unbiased likelihood estimation, the absolute value of each element in the signal x(n) is taken, and then sorted from small to large. The new signal sequence f(k) is obtained by taking the square of each element. Its function is that when the noise is less distributed in the high frequency band, the threshold estimation method can better extract the weak signal.

f(k)=(sort(|x|)) ² , k=(0,1,...,N-1)

In the formula, sort is the sorting order, and N is the sampling length of the original UHF signal.

If the square root of the kth element of the new signal sequence f(k) is taken as the given threshold λ _k , namely:

Then the risk generated by this threshold is:

According to the obtained risk curve Rish(k), record the value corresponding to the minimum risk point k _min , then the rigrsure threshold is:

(3) Wavelet reconstruction: The selection of the threshold function is the soft threshold denoising method in wthresh. Its function is to make the overall continuity of the wavelet coefficients better, so that the estimated signal will not generate additional oscillations. When the absolute value of the wavelet coefficient w is less than the given threshold, it is set to zero; when it is greater than the threshold, it is subtracted from the threshold, namely:

In the formula, w _λ is the wavelet coefficient after the threshold is applied.

After the processing of the above steps, the wavelet noise reduction processing of the UHF partial discharge signal can be completed.

It can be seen from the above description that the method for locating UHF partial discharge defects provided by the present application can perform wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal.

In one embodiment, referring to FIG. 3 , the discharge noise reduction signal includes: a first discharge noise reduction signal and a second discharge noise reduction signal; the discharge noise reduction signal is subjected to secondary correlation weighting processing to obtain the discharge time delayed signals, including:

S301: Perform an autocorrelation operation on the first discharge noise reduction signal to obtain an autocorrelation operation result R ₁₁ ;

S302: Perform a cross-correlation operation on the first discharge noise reduction signal and the second discharge noise reduction signal to obtain a cross-correlation operation result R ₁₂ ;

S303: use a generalized weighting function (the SCOT function is used in the embodiment of the present application) to perform a secondary cross-correlation weighting operation _on the autocorrelation operation result R11 and the cross-correlation operation result _R12 , and obtain a cross-correlation weighting operation result R _R11R12 ;

S304: Input the cross-correlation weighted operation result R _R11R12 into a power spectrum function to obtain a corresponding power spectrum;

S305: Perform inverse fast Fourier transform on the power spectrum to obtain the discharge delay signal.

It can be understood that the processing of the signal at this stage is implemented based on the secondary correlation operation weighted by the SCOT function. In the case of a low signal-to-noise ratio, the above-mentioned processing procedures from S301 to S305 have a good anti-noise effect, and a time-domain diagram of the time-delay signal that can reflect the real situation of the defect can be obtained. The algorithm process is shown in FIG. 11 .

Specifically, the signal after wavelet noise reduction (that is, the discharge noise reduction signal) is respectively subjected to autocorrelation operation and cross-correlation operation through Fourier transform, and the cross-correlation operation result R _R11R12 is subjected to weighting processing based on the SCOT function, and then The quadratic correlation algorithm is performed on the autocorrelation result and the weighted cross-correlation result R _R11R12 .

Specifically, when the signal-to-noise ratio of the signal is poor or there is correlation between noises, the simple cross-correlation result often results in inaccurate time delay estimation. The SCOT function can smooth and filter the main peak part of the cross-correlation result, and its function is to effectively highlight the main peak of the cross-correlation result and suppress noise interference. A more accurate time delay estimation can be obtained _{by performing quadratic correlation processing based on the autocorrelation result R11 and the cross-correlation result R R11R12 of} the weighting process. See the following formula for details:

为SCOT加权函数：Among them, R ₁₁ (τ) is the autocorrelation function of the signal x ₁ '(n), R ₁₂ (τ) is the cross-correlation function of the signals x ₁ '(n) and x' ₂ (n); W ₁₁ (ω) is the self-power spectrum of the signal x ₁ '(n); W ₁₂ (ω) is the cross-power spectrum of the signals x ₁ '(n) and x' ₂ (n); R ₁₂ (τ)' is the generalized weighted cross-power spectrum related results,

Weighting function for SCOT:

where W ₁ (ω) and W ₂ (ω) are the power spectra of the two signals x ₁ '(n) and x' ₂ (n).

After the processing in the above steps, the secondary correlation weighting processing on the discharge noise reduction signal can be completed to obtain the discharge time delay signal.

In an embodiment, referring to FIG. 4 , the determining the location of the UHF partial discharge defect according to the discharge time delay signal includes:

S401: Perform cubic spline interpolation processing on the discharge delay signal to obtain an interpolation result;

S402: Perform delay peak detection on the interpolation result to determine a corresponding delay peak;

S403: Determine the location of the UHF partial discharge defect according to the time delay peak value.

It can be understood that the cubic spline interpolation processing is performed on the time delay result processed by the quadratic correlation algorithm, and the data near the peak is smoothed and fitted, which can improve the accuracy of the peak point selection, and finally calculate the distance difference according to the peak time. , and output the position of the partial discharge fault point of the GIS. The specific implementation process is shown in Figure 12.

Specifically, the so-called cubic spline interpolation operation is to perform m times of segmentation on the interval [p, q] for the time delay result after the cross-correlation processing of the signal length of N, and the delay result of each segment is performed. Cubic spline interpolation processing. Because the cubic spline interpolation function has good stability and convergence, it can fit the delay result after cross-correlation processing, and the delay estimation can be more accurate while maintaining the peak value.

Further, let f(x) be the processed delay result, which is a continuously differentiable function on the interval [p, q], and is given in this interval:

p=x ₀ <x ₁ <x ₂ <…<x _m =q

Let the cubic spline function g(x) on the interval [x _i-1 , x _i ] be:

g(x _i )=a _i x ³ +b _i x ² +c _i x+d _i ,x∈(x _i-1 ,x _i ),i=1,2,...,m

In the formula, a _i , b _i , c _i , d _i are undetermined coefficients, and the interpolation conditions must be satisfied:

f(x _i )=g(x _i ),(i=0,1,...,m)

After solving the four undetermined coefficients in the interval [ _xi-1 , x _i ], the interpolation function g( _xi ) on the sub-interval can be obtained, which is divided into m sub-intervals, so 4m coefficients need to be solved, because f( The second derivative of x) in the interval [p, q] is continuous, so the nodes of the spline should satisfy:

At this time, two conditions are needed to determine the distance function g(x). The endpoint value of the interval can be selected as the two boundary conditions, x ₀ =p, x _m =q, we can get:

The first derivative when x ₀ =p and x _m =q are known:

The second derivative when x ₀ =p and x _m =q are known:

That is, the natural boundary conditions are:

g"(x _m )=f"(x _m )=0

To sum up, the joint solution can obtain the cubic spline interpolation function g(x _i ).

It can be seen from the above description that the UHF partial discharge defect location method described in the present application can determine the location of the UHF partial discharge defect according to the discharge time delay signal.

In order to illustrate the UHF partial discharge defect location method described in this application more clearly, an actual example is now given.

There is a partial discharge defect in a substation GIS. The signal was obtained through the electrical detection of the ultra-high frequency band at the scene, and it was preliminarily judged that the T0321 isolation switch had partial discharge defects. Install external UHF PD sensors on both sides of the isolation switch, as shown in Figure 13. The time difference of manual signal analysis is 2.2ns, and the distance difference is 66cm, as shown in Figure 14 and Figure 15. Using the data analysis and signal processing software to simulate the method described in this application, it can be analyzed and calculated that the time difference is 3.8 ns, the distance difference is 114 cm, and the peak value is shown in FIG. 5 . After the GIS equipment was disassembled after returning to the factory, the measured fault difference distance was about 135cm, which confirmed the accuracy and usability of the method described in this application.

Based on the same inventive concept, an embodiment of the present application further provides a device for locating a UHF partial discharge defect, which can be used to implement the methods described in the foregoing embodiments, as described in the following embodiments. Since the principle of the UHF partial discharge defect locating device to solve the problem is similar to the UHF partial discharge defect locating method, the implementation of the UHF partial discharge defect locating device can refer to the implementation of the determination method based on the software performance benchmark. Repeat. As used below, the term "unit" or "module" may be a combination of software and/or hardware that implements a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, implementations in hardware, or a combination of software and hardware, are also possible and contemplated.

In one embodiment, referring to FIG. 5 , in order to accurately locate UHF partial discharge defects, the present application provides a UHF partial discharge defect locating device, including: a noise reduction processing unit 501 , a time delay processing unit 502 and Defect locating unit 503 .

A noise reduction processing unit 501, configured to perform wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal;

A delay processing unit 502, configured to perform secondary correlation weighting processing on the discharge noise reduction signal to obtain a discharge delay signal;

The defect locating unit 503 is configured to determine the location of the UHF partial discharge defect according to the discharge time delay signal.

In an embodiment, referring to FIG. 6 , the noise reduction processing unit 501 includes: a wavelet transform module 601 , a filtering module 602 and a noise reduction module 603 .

A wavelet transform module 601, configured to perform wavelet transform on the UHF partial discharge signal by using a wavelet basis to obtain a corresponding wavelet signal;

A filtering module 602, configured to perform filtering and noise reduction processing on the wavelet signal to obtain a corresponding filtered signal;

The noise reduction module 603 is configured to perform inverse wavelet transform on the filtered signal to obtain the discharge noise reduction signal.

In an embodiment, referring to FIG. 7 , the discharge noise reduction signal includes: a first discharge noise reduction signal and a second discharge noise reduction signal; the delay processing unit 502 includes: an autocorrelation operation module 701 , a cross-correlation operation Module 702 , a power spectrum determination module 703 and a delay processing module 704 .

The autocorrelation operation module 701 is configured to perform an autocorrelation operation on the first discharge noise reduction signal to obtain an autocorrelation operation result;

A cross-correlation operation module 702 is configured to perform cross-correlation operation on the first discharge noise reduction signal and the second discharge noise reduction signal to obtain a cross-correlation operation result; and use a generalized weighting function to compare the autocorrelation operation result with the The cross-correlation operation result is subjected to a second cross-correlation weighting operation to obtain a cross-correlation weighting operation result;

a power spectrum determination module 703, configured to input the cross-correlation weighted operation result into a power spectrum function to obtain a corresponding power spectrum;

A delay processing module 704, configured to perform inverse fast Fourier transform on the power spectrum to obtain the discharge delay signal.

In an embodiment, referring to FIG. 8 , the defect location unit 503 includes: an interpolation processing module 801 , a peak determination module 802 and a defect location module 803 .

An interpolation processing module 801, configured to perform cubic spline interpolation processing on the discharge delay signal to obtain an interpolation result;

a peak determining module 802, configured to perform delay peak detection on the interpolation result, and determine a corresponding delay peak;

The defect location module 803 is configured to determine the location of the UHF partial discharge defect according to the time delay peak value.

From a hardware perspective, in order to accurately locate UHF partial discharge defects, the present application provides an embodiment of an electronic device for implementing all or part of the UHF partial discharge defect localization method, The electronic equipment specifically includes the following contents:

a processor, a memory, a communications interface, and a bus; wherein, the processor, memory, and communication interface communicate with each other through the bus; the communication interface is used to implement the Information transmission between the UHF partial discharge defect locating device and related equipment such as core business systems, user terminals, and related databases; the logic controller may be a desktop computer, a tablet computer, a mobile terminal, etc., and this embodiment is not limited thereto. In this embodiment, the logic controller may be implemented with reference to the embodiment of the method for locating UHF partial discharge defects and the embodiment of the device for locating UHF partial discharge defects in the embodiment, the contents of which are incorporated herein. The repetition will not be repeated.

It can be understood that the user terminal may 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, a smart wearable device, and the like. Wherein, the smart wearable device may include smart glasses, smart watches, smart bracelets, and the like.

In practical applications, part of the method for locating UHF partial discharge defects may be performed on the side of the electronic device as described above, or all operations may be completed in the client device. Specifically, the selection can be made according to the processing capability of the client device and the limitations of the user's usage scenario. This application does not limit this. The client device may also include a processor if all operations are performed in the client device.

The above-mentioned client device may have a communication module (ie, a communication unit), which may be connected in communication with a remote server to realize data transmission with the server. The server may include a server on the side of the task scheduling center, 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, a server cluster composed of multiple servers, or a server structure of a distributed device.

FIG. 9 is a schematic block diagram of a system configuration of an electronic device 9600 according to an embodiment of the present application. As shown in FIG. 9 , the electronic device 9600 may include a central processing unit 9100 and a memory 9140 ; the memory 9140 is coupled to the central processing unit 9100 . Notably, this FIG. 9 is exemplary; other types of structures may be used in addition to or in place of this structure to implement telecommunication functions or other functions.

In one embodiment, the function of the UHF partial discharge defect location method may be integrated into the central processing unit 9100 . Among them, the central processing unit 9100 can be configured to perform the following controls:

S101: Perform wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal;

S102: Perform secondary correlation weighting processing on the discharge noise reduction signal to obtain a discharge time delay signal;

S103: Determine the location of the UHF partial discharge defect according to the discharge delay signal.

It can be seen from the above description that the method and device for locating UHF partial discharge defects provided by the present application can perform noise reduction processing on the collected UHF partial discharge signal based on wavelet transform, so that the signal is more pure and the signal-to-noise ratio is improved. ; Perform cross-correlation operation on the UHF partial discharge signal after noise reduction, and then perform secondary correlation operation after weighting based on the SCOT function, so that the spectral peaks are more prominent and true under the condition of low signal-to-noise ratio; The time delay of the operation result is subjected to cubic spline interpolation operation, and the time delay result is smoothed, which improves the accuracy of peak value selection. To sum up, the method and device for locating UHF partial discharge defects provided by the present application can improve the accuracy of on-site GIS UHF partial discharge defect locating, and provide a reliable basis for on-site defect detection and fault analysis.

In another embodiment, the UHF partial discharge defect locating device may be configured separately from the central processing unit 9100, for example, the UHF partial discharge defect locating device of the data composite transmission device may be configured as a chip connected to the central processing unit 9100, The function of the UHF partial discharge defect localization method is realized through the control of the central processing unit.

As shown in FIG. 9 , the electronic device 9600 may further 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 include all the components shown in FIG. 9 ; in addition, the electronic device 9600 may also include components not shown in FIG. 9 , and reference may be made to the prior art.

As shown in FIG. 9 , a central processing unit 9100 , sometimes referred to as a controller or operational control, may include a microprocessor or other processor device and/or logic device, and the central processing unit 9100 receives input and controls various aspects of the electronic device 9600 component operation.

The memory 9140, for example, may be 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 can be stored, and a program executing the related information can also be stored. And the central processing unit 9100 can execute the program stored in the memory 9140 to realize information storage or processing.

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 for displaying display objects such as images and characters. The display can be, for example, but not limited to, an LCD display.

The memory 9140 may be solid state memory such as read only memory (ROM), random access memory (RAM), SIM card, and the like. There may also be memories that retain information even when powered off, selectively erased and provided with more data, examples of which are sometimes referred to as EPROMs or the like. Memory 9140 may also be some other type of device. Memory 9140 includes buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 may include an application/function storage part 9142 for storing application programs and function programs or for performing operations of the electronic device 9600 through the central processing unit 9100 .

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

The communication module 9110 is the transmitter/receiver 9110 that transmits and receives signals via the antenna 9111 . A communication module (transmitter/receiver) 9110 is coupled to the central processing unit 9100 to provide input signals and receive output signals, which may be the same as in the case of conventional mobile communication terminals.

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 local area network module. Communication module (transmitter/receiver) 9110 is also coupled to speaker 9131 and microphone 9132 via audio processor 9130 to provide audio output via speaker 9131 and to receive audio input from microphone 9132 for general telecommunication functions. Audio processor 9130 may include any suitable buffers, decoders, amplifiers, and the like. In addition, the audio processor 9130 is also coupled to the central processing unit 9100, thereby enabling recording on the local unit through the microphone 9132, and enabling playback of the sound stored on the local unit through the speaker 9131.

The embodiments of the present application also provide a computer-readable storage medium capable of implementing all the steps in the UHF partial discharge defect location method in which the execution body is the server or the client in the above-mentioned embodiments, and the computer-readable storage medium stores There is a computer program, when the computer program is executed by the processor, it realizes all the steps of the UHF partial discharge defect location method in the above-mentioned embodiment where the execution body is the server or the client. For example, when the processor executes the computer program, it realizes The following steps:

S101: Perform wavelet noise reduction processing on the obtained UHF partial discharge signal to obtain a corresponding discharge noise reduction signal;

S102: Perform secondary correlation weighting processing on the discharge noise reduction signal to obtain a discharge time delay signal;

S103: Determine the location of the UHF partial discharge defect according to the discharge delay signal.

It can be seen from the above description that the method and device for locating UHF partial discharge defects provided by the present application can perform noise reduction processing on the collected UHF partial discharge signal based on wavelet transform, so that the signal is more pure and the signal-to-noise ratio is improved. ; Perform cross-correlation operation on the UHF partial discharge signal after noise reduction, and then perform secondary correlation operation after weighting based on the SCOT function, so that the spectral peaks are more prominent and real under the condition of low signal-to-noise ratio; The time delay of the operation result is subjected to cubic spline interpolation operation, and the time delay result is smoothed, which improves the accuracy of peak value selection. To sum up, the method and device for locating UHF partial discharge defects provided by this application can improve the accuracy of on-site GIS UHF partial discharge defect locating, and provide a reliable basis for on-site defect detection and fault analysis.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (apparatus), and computer program products according to embodiments of the invention. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

In the present invention, the principles and implementations of the present invention are described by using specific embodiments, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; The idea of the invention will have changes in the specific embodiments and application scope. To sum up, the contents of this specification should not be construed as limiting the invention.

Claims (10)

1. An ultrahigh frequency partial discharge defect positioning method is characterized by comprising the following steps:

performing wavelet denoising processing on the obtained ultrahigh frequency partial discharge signal to obtain a corresponding discharge denoising signal;

performing secondary correlation weighting processing on the discharging noise reduction signal to obtain a discharging time delay signal;

and determining the position of the ultrahigh frequency partial discharge defect according to the discharge time delay signal.

2. The ultrahigh frequency partial discharge defect positioning method according to claim 1, wherein the performing wavelet denoising processing on the acquired ultrahigh frequency partial discharge signal to obtain a corresponding discharge denoising signal comprises:

performing wavelet transformation on the ultrahigh frequency partial discharge signal by using a wavelet basis to obtain a corresponding wavelet signal;

filtering and denoising the wavelet signals to obtain corresponding filtering signals;

and carrying out inverse wavelet transform on the filtering signal to obtain the discharging noise reduction signal.

3. The ultrahigh frequency partial discharge defect locating method according to claim 1, wherein the discharge noise reduction signal comprises: a first discharging noise reduction signal and a second discharging noise reduction signal; the performing second correlation weighting processing on the discharging noise reduction signal to obtain a discharging time delay signal includes:

performing autocorrelation operation on the first discharging noise reduction signal to obtain an autocorrelation operation result;

performing cross-correlation operation on the first discharging noise reduction signal and the second discharging noise reduction signal to obtain a cross-correlation operation result;

performing secondary cross-correlation weighting operation on the self-correlation operation result and the cross-correlation operation result by using a generalized weighting function to obtain a cross-correlation weighting operation result;

inputting the cross-correlation weighting operation result into a power spectrum function to obtain a corresponding power spectrum;

and performing fast Fourier inverse transformation on the power spectrum to obtain the discharge time delay signal.

4. The ultrahigh frequency partial discharge defect positioning method according to claim 1, wherein the determining the position of the ultrahigh frequency partial discharge defect according to the discharge time delay signal comprises:

carrying out cubic spline interpolation processing on the discharge time delay signal to obtain an interpolation result;

carrying out time delay peak value detection on the interpolation result, and determining a corresponding time delay peak value;

and determining the position of the ultrahigh frequency partial discharge defect according to the time delay peak value.

5. An ultrahigh frequency partial discharge defect locating device, comprising:

the noise reduction processing unit is used for performing wavelet noise reduction processing on the acquired ultrahigh frequency partial discharge signal to obtain a corresponding discharge noise reduction signal;

the time delay processing unit is used for carrying out secondary correlation weighting processing on the discharging noise reduction signal to obtain a discharging time delay signal;

and the defect positioning unit is used for determining the position of the ultrahigh frequency partial discharge defect according to the discharge time delay signal.

6. The UHF partial discharge defect locating device according to claim 5, wherein the noise reduction processing unit comprises:

the wavelet transformation module is used for carrying out wavelet transformation on the ultrahigh frequency partial discharge signal by utilizing a wavelet basis to obtain a corresponding wavelet signal;

the filtering module is used for carrying out filtering and denoising processing on the wavelet signals to obtain corresponding filtering signals;

and the denoising module is used for carrying out inverse wavelet transform on the filtering signal to obtain the discharging denoising signal.

7. The uhf local discharge defect locator of claim 5, wherein the discharge noise reduction signal comprises: a first discharging noise reduction signal and a second discharging noise reduction signal; the delay processing unit includes:

the autocorrelation operation module is used for carrying out autocorrelation operation on the first discharging noise reduction signal to obtain an autocorrelation operation result;

the cross-correlation operation module is used for performing cross-correlation operation on the first discharging noise reduction signal and the second discharging noise reduction signal to obtain a cross-correlation operation result; performing secondary cross-correlation weighting operation on the self-correlation operation result and the cross-correlation operation result by using a generalized weighting function to obtain a cross-correlation weighting operation result;

the power spectrum determination module is used for inputting the cross-correlation weighting operation result into a power spectrum function to obtain a corresponding power spectrum;

and the time delay processing module is used for performing inverse fast Fourier transform on the power spectrum to obtain the discharge time delay signal.

8. The UHF partial discharge defect localization apparatus according to claim 5, wherein the defect localization unit comprises:

the interpolation processing module is used for carrying out cubic spline interpolation processing on the discharge time delay signal to obtain an interpolation result;

the peak value determining module is used for carrying out time delay peak value detection on the interpolation result and determining a corresponding time delay peak value;

and the defect positioning module is used for determining the position of the ultrahigh frequency partial discharge defect according to the time delay peak value.

9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the uhf partial discharge defect localization method of any one of claims 1 to 4 when executing the program.

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the uhf partial discharge defect localization method according to any one of claims 1 to 4.

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