CN117031382A - Single-ended traveling wave device verification method based on signal-to-noise ratio and sine fitting method - Google Patents
Single-ended traveling wave device verification method based on signal-to-noise ratio and sine fitting method Download PDFInfo
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Abstract
The invention provides a single-ended traveling wave device verification method based on a signal-to-noise ratio and a sine fitting method, which comprises the steps of firstly reading actual measurement traveling wave ranging device recording data by installing a single-ended traveling wave ranging device, screening the actual measurement traveling wave ranging device recording data by using a signal-to-noise ratio method, comparing the signal-to-noise ratio SNR of the recording data with a set value, and judging whether the recording data can be used for traveling wave ranging device verification; then, based on a sine fitting method, performing wave recording waveform prolongation processing on the actually measured traveling wave distance measuring device, outputting fault waveforms to the traveling wave distance measuring device through a traveling wave calibrator, and performing traveling wave distance measurementThe device outputs the ranging resultdRanging resultsdComparing with the actual fault position, if the distance measurement result error is deltadIf the distance measurement result is smaller than the set value, the distance measurement result of the traveling wave distance measurement device is accurate, otherwise, the distance measurement result of the traveling wave distance measurement device is inaccurate. According to the method, the measured traveling wave data is utilized to check the single-ended traveling wave distance measuring device, and the distance measuring accuracy of the single-ended traveling wave distance measuring device is improved.
Description
Technical Field
The invention belongs to the technical field of power system automation, and particularly relates to a single-ended traveling wave device verification method based on a signal-to-noise ratio and sine fitting method.
Background
The traveling wave fault location technology is mature, but the technology aiming at the verification of the traveling wave fault location device is far behind the traveling wave location technology, and a unified specification is not formed yet. When the simulation data is adopted for verification, the ranging results of all factories can meet the requirements; however, when using measured data, substantially all manufacturers fail to achieve ranging. For this reason, firstly, the difference between each traveling wave ranging device comprises the differences of wave recording quality, wave recording time window, sampling rate and the like, secondly, the selection of measured data is unsuitable, and thirdly, the characteristics of the measured data are determined. How to use measured data to verify the traveling wave fault distance measuring device has become a problem to be solved.
As shown in FIG. 1, when the initial value and the end value of the actually measured traveling wave data are not zero, a transition phenomenon is generated as shown in FIG. 2 after the traveling wave data are output by the traveling wave calibrator, and the larger the absolute value of the initial value and the end value is, the more obvious the transition phenomenon is; if the waveform output by the tester is directly connected to the traveling wave fault distance measuring device, the tail end step is mistakenly regarded as a fault point, so that the test is invalid. The test data needs to be "extended" before being input into the tester, so that the initial part is zero or approaches zero, and the end part is slowly attenuated to zero or the end value is zero.
In actual operation, most electric power part workers know the traveling wave ranging concept at a glance, and the traveling wave fault ranging is used for trade, so that popularization and application of the traveling wave ranging device are not favored. Comparing the difference between the actual measured fault waveform and the simulated fault waveform by analyzing the existing traveling wave fault ranging method and the existing traveling wave ranging device testing method at home and abroad, and testing the single-ended traveling wave ranging device by utilizing the actual measured fault data and the simulated fault data; in order to ensure that the simulation fault waveform is close to the actual running state, and meanwhile, how to comprehensively test the traveling wave ranging device is pointed out, the test method of the traveling wave ranging device is verified to be practical and effective, and the method has important significance for improving the reliable running of the traveling wave fault ranging device.
Disclosure of Invention
In order to solve the defects in the prior art, the invention provides the single-ended traveling wave device calibration method based on the signal-to-noise ratio and the sine fitting method, which can improve the accuracy of the ranging result of the single-ended traveling wave ranging device and is easy to popularize and apply.
The invention adopts the technical scheme that: a single-ended traveling wave device verification method based on a signal-to-noise ratio and sine fitting method comprises the following steps:
step 1, installing a single-ended traveling wave distance measuring device in a transformer substation and a power plant booster station;
step 2, reading recorded wave data of the actually measured traveling wave distance measuring device;
step 3, screening the signal-to-noise ratio SNR of the wave recording data of the actually measured traveling wave distance measuring device by using a signal-to-noise ratio estimation method, wherein in the signal-to-noise ratio estimation method, the original signal of the wave recording data is denoised through wavelet transformation;
step 4, comparing the signal-to-noise ratio SNR of the screened recording data with a set value, and judging whether the recording data can be used for checking a traveling wave ranging device;
step 5, performing wave record waveform continuation processing on an actual measurement traveling wave ranging device which can be used for checking the traveling wave ranging device based on a sine fitting method, wherein in the sine fitting method, fitting is performed through a least square method;
step 6, outputting fault waveforms to the traveling wave ranging device through the traveling wave check meter by using the extended wave recording waveforms;
step 7, outputting a ranging result to the fault waveform through the traveling wave ranging devicedWill range the resultdComparing with the actual fault position;
step 8, if the ranging result is error-deltadIf the distance measurement result is smaller than the set value, the distance measurement result of the traveling wave distance measurement device is accurate, otherwise, the distance measurement result of the traveling wave distance measurement device is inaccurate.
Further, the estimation formula of the signal-to-noise ratio estimation method in the step 3 is as follows:
wherein, the SNR is the signal-to-noise ratio of the wave recording data of the actually measured traveling wave distance measuring device;the data is an original signal of recording data; />The signal after the noise of the recording data is removed; />The noise elimination signal is the wave recording data;Mthe number of the recorded wave data; the sigma represents the sign of the sum,i=1 represents a slaveiStarting summing with a start value of 1; wherein the recorded data is denoised signal +.>Is to record wave by wavelet transformationData original Signal->And (5) denoising to obtain the final product.
Further, in the signal-to-noise ratio estimation method in step 3, the wavelet transformation noise-eliminating the original signal of the recording data includes the following steps:
step 3.1, performing small scale decomposition of signals, selecting a proper wavelet base according to noise signals contained in wave recording data, determining the number of layers of wavelet decomposition, and selecting a db4 wavelet base in this section, wherein the number of decomposition layers is 3;
step 3.2, performing noise estimation self-adaptive adjustment threshold according to each coefficient of wavelet decomposition, and specifically adjusting the threshold according to the estimation of different noises;
and 3.3, reconstructing the signal by utilizing a wavelet reconstruction formula to obtain the denoised signal.
In step 5, a fitting algorithm is performed based on parameter estimation, a signal model adopts a sine function, the traveling wave recording data is fitted by a least square method, and the sine frequency of the traveling wave recording data is the power frequency, and the rated frequency is 50Hz, so that the amplitude and the phase of the recording signal are estimated, and the expression of the waveform is obtained.
Further, the sine fitting method comprises the following steps:
the sine function model to be fitted is set as follows:
in the method, in the process of the invention,fitting an instantaneous value of the signal to the recorded data;Afitting amplitude values of sine functions of recording data;fthe rated frequency is 50Hz when the power grid normally operates; θ is the fitting initial phase of sine function of recording data, and θ takes the value space [0,2 pi ]]；tIs a time variable;
due tof50Hz,2πfIs 100 pi constant; unfolding (2)Obtaining:
order the，/>Then there are:
i.e. the parameter to be estimatedABecomes theta toa、bThe method comprises the steps of carrying out a first treatment on the surface of the The actually measured recording data and the time sequence thereof are discrete, the sampling interval is defined as Deltat, and the data recording sequence is set as the time 0, deltat, 2 Deltat, …,n-1) the measured wave recording data of Deltat isf 1 ，f 2 ，…，f n The method comprises the steps of carrying out a first treatment on the surface of the And 0, deltat, 2 Deltat, …, from formula (4)n-1) the fitting function value at time Δt is y 1 ，y 2 ，…，y n For the sum of squares of the error between the recorded data and the function fit value:
in the method, in the process of the invention,is the actual measured wave recording data; />Fitting data for the function;nrepresenting the number of the wave recording data and the function fitting data;jis an intermediate variable, without specific meaning,jthe value space of (2) is [1 ],n]the method comprises the steps of carrying out a first treatment on the surface of the The value of formula (5) is the smallest, and the condition +.>，The equation can be obtained:
in the method, in the process of the invention,represent the firstjTime points; and (3) making:
in which Q 11 、Q 12 、Q 21 、Q 22 、、/>Is an intermediate variable, without specific meaning; equation (7) can be written in matrix form:
in the method, in the process of the invention,Q、d、lfor calculating the matrix, no specific meaning exists; wherein the method comprises the steps of，/>，/>A and b can be obtained from formula (8) to obtain +.>Thus, the fitting sine function can be obtained.
Further, in step 4, if the signal-to-noise ratio SNR of the recording data is greater than or equal to 30, it is indicated that the recording data can be used for checking the traveling wave ranging device, otherwise, a set of recording data of the traveling wave ranging device needs to be replaced again.
Further, in step 8, if the ranging result error is deltadIf the distance is smaller than 300m, the distance measurement result of the traveling wave distance measurement device is accurate, otherwise, the distance measurement result of the traveling wave distance measurement device is inaccurate.
The beneficial effects of the invention are as follows: the single-ended traveling wave device verification method based on the signal-to-noise ratio and the sine fitting method screens measured data from measured fault recording data by utilizing the signal-to-noise ratio, and aims at the characteristics that the time window problem of the measured data and the starting value and the ending value are not zero, and adopts a sine fitting method to carry out prolongation treatment on the measured fault waveform; considering the limitation of actual measurement faults, the traveling wave fault distance measuring device can be checked by combining simulation data.
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In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:
FIG. 1 is a schematic waveform diagram of measured traveling wave data with non-zero initial and end values;
FIG. 2 is a schematic waveform diagram of the traveling wave verifier of FIG. 1 after output;
FIG. 3 is a flow chart of a verification method of the present invention;
FIG. 4 is a test structure diagram of the single-ended traveling wave ranging device of the present invention;
FIG. 5 is a schematic waveform diagram of three-phase recording data according to application example 1 of the present invention;
FIG. 6 is a schematic waveform diagram of the recorded wave data of the actual measurement traveling wave ranging device according to application example 2 of the present invention;
FIG. 7 is a schematic waveform diagram showing the result of the recording data extension processing according to application example 2 of the present invention;
FIG. 8 is a schematic waveform diagram of the recorded wave data of the actual measurement traveling wave ranging device according to application example 3 of the present invention;
fig. 9 is a waveform diagram of a result of the recording data extension processing of application example 3 of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
When the initial value and the end value of the actually measured traveling wave data are not zero, a transition phenomenon is generated after the traveling wave data are output by a traveling wave calibrator, and the larger the absolute value of the initial value and the end value is, the more obvious the transition phenomenon is; if the waveform output by the tester is directly connected to the traveling wave fault distance measuring device, the tail end step is mistakenly regarded as a fault point, so that the problem of test failure is caused; in order to ensure that the simulation fault waveform is close to the actual running state, how to comprehensively test the traveling wave ranging device is pointed out, the embodiment provides a single-ended traveling wave device checking method based on a signal-to-noise ratio and a sine fitting method, and the single-ended traveling wave device checking method based on the signal-to-noise ratio and the sine fitting method can improve the accuracy of the ranging result of the single-ended traveling wave ranging device and is easy to popularize and apply.
Specifically, as shown in fig. 3, the single-ended traveling wave device calibration method based on the signal-to-noise ratio and sine fitting method comprises the following specific processes:
and installing single-ended traveling wave distance measurement devices in the transformer substation and the power plant booster station for positioning faults of the power transmission lines of the single-ended traveling wave distance measurement devices. Firstly, reading the recorded data of an actual measurement traveling wave distance measuring device, and screening the signal-to-noise ratio SNR of the recorded data of the actual measurement traveling wave distance measuring device by using a signal-to-noise ratio estimation method;
the estimation formula of the signal-to-noise ratio estimation method is as follows:
in the method, SNR is signal-to-noise of wave recording data of actually measured traveling wave distance measuring deviceRatio of;the data is an original signal of recording data; />The signal after the noise of the recording data is removed; />The noise elimination signal is the wave recording data; m is the number of the recorded wave data; the sigma represents the sign of the sum,i=1 represents a slaveiStarting summing with a start value of 1; wherein the recorded data is denoised signal +.>Is to use wavelet transformation to record the original signal of the data>And (5) denoising to obtain the final product.
The wavelet transformation noise elimination process for the original signal of the recording data is as follows: firstly, carrying out wavelet decomposition of signals, selecting a proper wavelet base according to noise signals contained in wave recording data, determining the number of layers of wavelet decomposition, and selecting db4 wavelet base in this section, wherein the number of decomposition layers is 3; then, according to each coefficient of wavelet decomposition, noise estimation self-adaptive adjustment threshold value is carried out, and the threshold value is adjusted according to the estimation of different noise in this section; finally, reconstructing the signal by utilizing a wavelet reconstruction formula to obtain a denoised signal; the wavelet reconstruction formula adopts the prior art and can refer to chapter 7 of books of electric power engineering signal processing application.
The wavelet transformation has excellent self-adaptive time-frequency characteristics, can reliably divide singular components and noise components in the travelling wave recording waveform, and has the effect of suppressing noise, so that the waveform subjected to wavelet transformation and noise elimination on the travelling wave recording waveform is used as a noise-free original signal.
And comparing the signal-to-noise ratio SNR of the screened recording data with a set value, and judging whether the recording data can be used for checking the traveling wave distance measuring device. If the SNR of the recording data is greater than or equal to 30, the recording data can be used for checking the traveling wave ranging device, otherwise, a group of recording data of the traveling wave ranging device needs to be replaced again.
When the actually measured wave ranging device recording data contains large noise, after passing through the traveling wave ranging device calibrator, the wave head is submerged by the noise, the wave head cannot be identified at all, and a large number of experiments prove that when the signal-to-noise ratio SNR of the recording data is larger than 30, the recording data can be used for testing the traveling wave fault device.
And then, carrying out wave record waveform prolongation processing on the actually measured traveling wave distance measuring device based on a sine fitting method, and outputting fault waveforms to the traveling wave distance measuring device through a traveling wave check meter, wherein M in the graph of FIG. 4 represents a line M end, N represents a line N end and F represents a line fault occurrence position. The sine fitting method is a fitting algorithm based on parameter estimation, a signal model adopts a sine function, the least square method is used for fitting the traveling wave recording data, aiming at the fact that the sine frequency of the traveling wave recording data is the power frequency, the rated frequency of a power grid in China is 50Hz, and then only the amplitude and the phase of the recording signal are needed to be estimated, so that an expression of the sine fitting algorithm is obtained.
Therefore, let the sine function model to be fitted be:
in the method, in the process of the invention,fitting an instantaneous value of the signal to the recorded data;Afitting amplitude values of sine functions of recording data;fthe rated frequency is 50Hz when the power grid normally operates; θ is the fitting initial phase of sine function of recording data, and θ takes the value space [0,2 pi ]]；tIs a time variable;
due tof50Hz,2πfIs 100 pi constant; expanding the formula (2) to obtain:
order the，/>Then there are:
i.e. the parameter to be estimatedABecomes theta toa、bThe method comprises the steps of carrying out a first treatment on the surface of the The actually measured recording data and the time sequence thereof are discrete, the sampling interval is defined as Deltat, the data recording sequence is set as time 0, deltat, 2 Deltat and …, and the (n-1) Deltat actually measured recording data isf 1 ，f 2 ，…，f n The method comprises the steps of carrying out a first treatment on the surface of the From formula (4), the fitting function value at time (n-1) Δt is y, which is 0, Δt,2 Δt, … 1 ，y 2 ，…，y n For the sum of squares of the error between the recorded data and the function fit value:
in the method, in the process of the invention,is the actual measured wave recording data; />Fitting data for the function;nrepresenting the number of the wave recording data and the function fitting data;jis an intermediate variable, without specific meaning,jthe value space of (2) is [1 ],n]。
the minimum value of formula (5) is required to satisfy the condition，/>The equation can be obtained:
in the method, in the process of the invention,represent the firstjA time point.
And (3) making:
in which Q 11 、Q 12 、Q 21 、Q 22 、、/>Is an intermediate variable, and has no specific meaning.
Equation (7) can be written in matrix form:
in the method, in the process of the invention,Q、d、lfor calculating the matrix, there is no specific meaning.
Wherein the method comprises the steps of，/>，/>A and b can be obtained from formula (8) to obtain +.>Thus, the fitting sine function can be obtained.
Aiming at the characteristics that the time window problem, the starting value and the ending value of the actually measured recording data are not zero, the least square method is used for fitting the traveling wave recording data, the starting point and the ending point of the actually measured recording data are prolonged, the error of the ranging result of the single-ended traveling wave ranging device due to the fact that the time window problem, the starting value and the ending value of the actually measured recording data are not zero is avoided, the reliability of single-ended traveling wave ranging verification is improved, and meanwhile the single-ended traveling wave ranging device is facilitated to improve the ranging accuracy.
Finally, the traveling wave distance measuring device outputs a distance measuring resultdWill range the resultdAnd comparing with the actual fault position, if the ranging result error Deltad is smaller than the set value 300m, indicating that the ranging result of the traveling wave ranging device is accurate, otherwise, indicating that the ranging result of the traveling wave ranging device is inaccurate.
In order to verify the single-ended traveling wave device verification method based on the signal-to-noise ratio and sine fitting method, the following practical application verification is performed:
application example 1
Firstly, reading wave recording data of a measured traveling wave distance measuring device of a fault of a transmission line, as shown in fig. 5, screening the wave recording data of the measured traveling wave distance measuring device by using a signal-to-noise ratio method, and calculating signal-to-noise ratios (SNR) of three-phase wave recording data to be 15.89, 12.71 and 23.56 respectively, wherein the signal-to-noise ratios (SNR) of the three-phase wave recording data are smaller than 30, so that the wave recording data cannot be used for checking the traveling wave distance measuring device, and a group of wave recording data of the traveling wave distance measuring device need to be replaced.
Application example 2
Firstly, reading wave recording data of a fault actually-measured traveling wave distance measuring device of a bird hazard transmission line, as shown in fig. 6, screening the wave recording data of the actually-measured traveling wave distance measuring device by using a signal-to-noise ratio method, calculating the signal-to-noise ratio SNR of the wave recording data to be 35.24 respectively, and if the signal-to-noise ratio SNR of the wave recording data is larger than 30, indicating that the wave recording data can be used for checking the traveling wave distance measuring device. And then, carrying out wave record waveform extension processing on the actually measured traveling wave distance measuring device based on a sine fitting method, wherein the waveform after the extension processing is shown in fig. 7, outputting a fault waveform to the traveling wave distance measuring device through a traveling wave check meter, and outputting a distance measuring result d of the traveling wave distance measuring device to be 30.2km. And according to the line inspection result of the operator, the fault distance is 30.1km, the distance measurement result d is compared with the actual fault position, and if the distance measurement result error delta d is smaller than 300m, the distance measurement result of the traveling wave distance measurement device is accurate.
Application example 3
Firstly, reading a record of a fault actually-measured traveling wave distance measuring device of a lightning transmission lineAs shown in fig. 8, the wave data is obtained by screening the wave recording data of the actually measured traveling wave distance measuring device by using a signal-to-noise ratio method, and calculating the signal-to-noise ratio SNR of the wave recording data to be 34.37 respectively, wherein the signal-to-noise ratio SNR of the wave recording data is greater than 30, so that the wave recording data can be used for checking the traveling wave distance measuring device. Then, based on a sine fitting method, waveform extension processing is carried out on the actual measurement wave form of the traveling wave distance measuring device, the waveform after the extension processing is shown in figure 9, fault waveforms are output to the traveling wave distance measuring device through the traveling wave check meter, and the traveling wave distance measuring device outputs a distance measuring resultd78.5km. According to the line inspection result of the operator, the fault distance is 78.79km, and the distance measurement resultdComparing with the actual fault position, the error of the ranging result is deltadAnd if the distance is smaller than 300m, the distance measurement result of the traveling wave distance measurement device is accurate.
In summary, the single-ended traveling wave device verification method based on the signal-to-noise ratio and the sine fitting method screens actual measurement data from actual measurement fault recording data by utilizing the signal-to-noise ratio, and adopts a sine fitting method to carry out prolongation treatment on actual measurement fault waveforms aiming at the characteristics that the time window problem of the actual measurement data and the starting value and the ending value are not zero; considering the limitation of actual measurement faults, the traveling wave fault distance measuring device can be checked by combining simulation data. The single-ended traveling wave device calibration method based on the signal-to-noise ratio and the sine fitting method is practical and effective through verification, and has important significance for improving the reliable operation of the traveling wave fault distance measuring device.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (7)
1. The single-ended traveling wave device verification method based on the signal-to-noise ratio and sine fitting method is characterized by comprising the following steps of:
step 1, installing a single-ended traveling wave distance measuring device in a transformer substation and a power plant booster station;
step 2, reading recorded wave data of the actually measured traveling wave distance measuring device;
step 3, screening the signal-to-noise ratio SNR of the wave recording data of the actually measured traveling wave distance measuring device by using a signal-to-noise ratio estimation method, wherein in the signal-to-noise ratio estimation method, the original signal of the wave recording data is denoised through wavelet transformation;
step 4, comparing the signal-to-noise ratio SNR of the screened recording data with a set value, and judging whether the recording data can be used for checking a traveling wave ranging device;
step 5, performing wave record waveform continuation processing on an actual measurement traveling wave ranging device which can be used for checking the traveling wave ranging device based on a sine fitting method, wherein in the sine fitting method, fitting is performed through a least square method;
step 6, outputting fault waveforms to the traveling wave ranging device through the traveling wave check meter by using the extended wave recording waveforms;
step 7, outputting a ranging result to the fault waveform through the traveling wave ranging devicedWill range the resultdComparing with the actual fault position;
step 8, if the ranging result is error-deltadIf the distance measurement result is smaller than the set value, the distance measurement result of the traveling wave distance measurement device is accurate, otherwise, the distance measurement result of the traveling wave distance measurement device is inaccurate.
2. The calibration method of a single-ended traveling wave device based on a signal-to-noise ratio and a sine fitting method according to claim 1, wherein the estimation formula of the signal-to-noise ratio estimation method in the step 3 is as follows:wherein, the SNR is the signal-to-noise ratio of the wave recording data of the actually measured traveling wave distance measuring device; />The data is an original signal of recording data; />The signal after the noise of the recording data is removed; />The noise elimination signal is the wave recording data;Mthe number of the recorded wave data; the sigma represents the sign of the sum,i=1 represents a slaveiStarting summing with a start value of 1; wherein the recorded data is denoised signal +.>Is to use wavelet transformation to record the original signal of the data>And (5) denoising to obtain the final product.
3. The method for checking a single-ended traveling wave device based on a signal-to-noise ratio and a sine fitting method according to claim 2, wherein in the signal-to-noise ratio estimation method in step 3, the wavelet transformation noise-eliminating the original signal of the recording data comprises the following steps:
step 3.1, wavelet decomposition of signals, namely selecting a proper wavelet base according to noise signals contained in wave recording data containing travelling waves, determining the number of layers of wavelet decomposition, wherein db4 wavelet base is selected in the section, and the number of decomposition layers is 3;
step 3.2, performing noise estimation self-adaptive adjustment threshold according to each coefficient of wavelet decomposition, and specifically adjusting the threshold according to the estimation of different noises;
and 3.3, reconstructing the signal by utilizing a wavelet reconstruction formula to obtain the denoised signal.
4. The single-ended traveling wave device verification method based on the signal-to-noise ratio and sine fitting method according to claim 1, wherein the single-ended traveling wave device verification method is characterized by: in step 5, a fitting algorithm is performed based on parameter estimation by sine fitting, a signal model adopts a sine function, the travelling wave recording data is fitted by a least square method, the sine frequency of the travelling wave recording data is the power frequency, and the rated frequency is 50Hz, so that the amplitude and the phase of the wave recording signal are required to be estimated, and the expression of the wave recording signal is obtained.
5. The single-ended traveling wave device verification method based on a signal-to-noise ratio and a sine fitting method according to claim 4, wherein the sine fitting method comprises the following steps:
the sine function model to be fitted is set as follows:
in the method, in the process of the invention,fitting an instantaneous value of the signal to the recorded data;Afitting amplitude values of sine functions of recording data;fthe rated frequency is 50Hz when the power grid normally operates; θ is the fitting initial phase of sine function of recording data, and θ takes the value space [0,2 pi ]]；tIs a time variable;
due tof50Hz,2πfIs 100 pi constant; expanding the formula (2) to obtain:
order the，/>The following steps are:
i.e. the parameter to be estimatedABecomes theta toa、bThe method comprises the steps of carrying out a first treatment on the surface of the The actually measured recording data and the time sequence thereof are discrete, the sampling interval is defined as Deltat, and the data recording sequence is set as the time 0, deltat, 2 Deltat, …,n-1) the measured wave recording data of Deltat isf 1 ，f 2 ，…，f n The method comprises the steps of carrying out a first treatment on the surface of the And 0, deltat, 2 Deltat, …, from formula (4)n-1) the fitting function value at time Δt is y 1 ，y 2 ，…，y n For the sum of squares of the error between the recorded data and the function fit value:
in the method, in the process of the invention,is the actual measured wave recording data; />Fitting data for the function;nrepresenting the number of the wave recording data and the function fitting data;jis an intermediate variable, without specific meaning,jthe value space of (2) is [1 ],n]the method comprises the steps of carrying out a first treatment on the surface of the The value of formula (5) is the smallest, and the condition +.>，The equation can be obtained:
in the method, in the process of the invention,represent the firstjTime points; and (3) making:
in which Q 11 、Q 12 、Q 21 、Q 22 、、/>Is an intermediate variable, without specific meaning; equation (7) can be written in matrix form:
in the method, in the process of the invention,Q、d、lfor calculating the matrix, no specific meaning exists; wherein the method comprises the steps of，/>，/>A and b can be obtained from formula (8) to obtain +.>Thus, the fitting sine function can be obtained.
6. The single-ended traveling wave device verification method based on the signal-to-noise ratio and sine fitting method according to claim 1, wherein the single-ended traveling wave device verification method is characterized by: in step 4, if the signal-to-noise ratio SNR of the recording data is greater than or equal to 30, it is indicated that the recording data can be used for checking the traveling wave ranging device, otherwise, a group of recording data of the traveling wave ranging device needs to be replaced again.
7. The single-ended traveling wave device verification method based on the signal-to-noise ratio and sine fitting method according to claim 1, wherein the single-ended traveling wave device verification method is characterized by: in step 8, if the ranging result error is deltadIf the distance is smaller than 300m, the distance measurement result of the traveling wave distance measurement device is accurate, otherwise, the distance measurement result of the traveling wave distance measurement device is inaccurate.
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Citations (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101666848A (en) * | 2009-10-15 | 2010-03-10 | 北京四方继保自动化股份有限公司 | Fault location method based on travelling wave |
| CN102680860A (en) * | 2012-06-08 | 2012-09-19 | 东华理工大学 | Automatic fault-point locating method for traveling-wave based fault location of high-voltage electric power lines |
| CN102928728A (en) * | 2012-10-30 | 2013-02-13 | 清华大学 | High-resistance grounding fault detection method based on zero-sequence current waveform distortion convexity and concavity |
| CN103091657A (en) * | 2012-11-12 | 2013-05-08 | 辽宁省电力有限公司 | Calibration method of traveling-wave fault location system |
| CN104459461A (en) * | 2014-11-20 | 2015-03-25 | 云南电网公司大理供电局 | Automatic fault data screening method based on power frequency sine fitting and correlation coefficients |
| CN105372559A (en) * | 2015-12-16 | 2016-03-02 | 昆明理工大学 | Chain type power transmission line single terminal fault location limited continuation method based on characteristic of fault traveling wave distribution along line |
| CN106526317A (en) * | 2016-10-21 | 2017-03-22 | 国家电网公司 | Phasor measurement accuracy assessment method and assessment apparatus for synchronized phasor measurement unit |
| CN107515355A (en) * | 2017-10-18 | 2017-12-26 | 国网江苏省电力公司南通供电公司 | Cable fault location device and its data processing method |
| CN207488476U (en) * | 2017-12-08 | 2018-06-12 | 云南电网有限责任公司文山供电局 | Travelling wave ranging calibration equipment |
| CN108196166A (en) * | 2018-01-11 | 2018-06-22 | 武汉三相电力科技有限公司 | Both-end travelling wave ranging method based on fault waveform starting point step-out time |
| CN207541250U (en) * | 2017-12-08 | 2018-06-26 | 云南电网有限责任公司文山供电局 | Automatically generate the travelling wave ranging calibration equipment of signal source |
| CN110109041A (en) * | 2019-06-03 | 2019-08-09 | 南方电网科学研究院有限责任公司 | Detection system and method of non-contact traveling wave distance measuring device |
| CN209373028U (en) * | 2018-10-29 | 2019-09-10 | 云南电网有限责任公司德宏供电局 | Travelling wave ranging equipment verification device and can self-test travelling wave ranging system |
| CN110967599A (en) * | 2019-12-11 | 2020-04-07 | 贵州电网有限责任公司 | Electric energy quality disturbance detection and positioning algorithm |
| CN210665925U (en) * | 2019-06-27 | 2020-06-02 | 云南电网有限责任公司文山供电局 | Fault data screening device for traveling wave sine fitting |
| CN112180210A (en) * | 2020-09-24 | 2021-01-05 | 华中科技大学 | Power distribution network single-phase earth fault line selection method and system |
| WO2021072913A1 (en) * | 2019-10-15 | 2021-04-22 | 国电南瑞科技股份有限公司 | Line protection traveling wave distance measurement method and apparatus |
| US20210156900A1 (en) * | 2019-11-25 | 2021-05-27 | Shandong University Of Technology | Method for fault location to single-terminal traveling wave |
| US20210293873A1 (en) * | 2020-03-18 | 2021-09-23 | Mitsubishi Electric Research Laboratories, Inc. | Transient based Fault Location Method for Ungrounded Power Distribution Systems |
| CN113533849A (en) * | 2021-06-15 | 2021-10-22 | 云南电力试验研究院(集团)有限公司 | New energy station frequency modulation device anti-disturbance testing method |
| CN113945806A (en) * | 2021-11-15 | 2022-01-18 | 昆明理工大学 | Flexible direct current transmission line single-end fault location method and system |
| CN114441897A (en) * | 2021-12-31 | 2022-05-06 | 深圳供电局有限公司 | Method for identifying arrival time difference of partial discharge pulse of distribution cable line |
| CN115684830A (en) * | 2022-10-13 | 2023-02-03 | 北京四方继保工程技术有限公司 | Fault location method and system based on COMTRADE |
-
2023
- 2023-10-10 CN CN202311306195.8A patent/CN117031382B/en active Active
Patent Citations (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101666848A (en) * | 2009-10-15 | 2010-03-10 | 北京四方继保自动化股份有限公司 | Fault location method based on travelling wave |
| CN102680860A (en) * | 2012-06-08 | 2012-09-19 | 东华理工大学 | Automatic fault-point locating method for traveling-wave based fault location of high-voltage electric power lines |
| CN102928728A (en) * | 2012-10-30 | 2013-02-13 | 清华大学 | High-resistance grounding fault detection method based on zero-sequence current waveform distortion convexity and concavity |
| CN103091657A (en) * | 2012-11-12 | 2013-05-08 | 辽宁省电力有限公司 | Calibration method of traveling-wave fault location system |
| CN104459461A (en) * | 2014-11-20 | 2015-03-25 | 云南电网公司大理供电局 | Automatic fault data screening method based on power frequency sine fitting and correlation coefficients |
| CN105372559A (en) * | 2015-12-16 | 2016-03-02 | 昆明理工大学 | Chain type power transmission line single terminal fault location limited continuation method based on characteristic of fault traveling wave distribution along line |
| CN106526317A (en) * | 2016-10-21 | 2017-03-22 | 国家电网公司 | Phasor measurement accuracy assessment method and assessment apparatus for synchronized phasor measurement unit |
| CN107515355A (en) * | 2017-10-18 | 2017-12-26 | 国网江苏省电力公司南通供电公司 | Cable fault location device and its data processing method |
| CN207541250U (en) * | 2017-12-08 | 2018-06-26 | 云南电网有限责任公司文山供电局 | Automatically generate the travelling wave ranging calibration equipment of signal source |
| CN207488476U (en) * | 2017-12-08 | 2018-06-12 | 云南电网有限责任公司文山供电局 | Travelling wave ranging calibration equipment |
| CN108196166A (en) * | 2018-01-11 | 2018-06-22 | 武汉三相电力科技有限公司 | Both-end travelling wave ranging method based on fault waveform starting point step-out time |
| CN209373028U (en) * | 2018-10-29 | 2019-09-10 | 云南电网有限责任公司德宏供电局 | Travelling wave ranging equipment verification device and can self-test travelling wave ranging system |
| CN110109041A (en) * | 2019-06-03 | 2019-08-09 | 南方电网科学研究院有限责任公司 | Detection system and method of non-contact traveling wave distance measuring device |
| CN210665925U (en) * | 2019-06-27 | 2020-06-02 | 云南电网有限责任公司文山供电局 | Fault data screening device for traveling wave sine fitting |
| WO2021072913A1 (en) * | 2019-10-15 | 2021-04-22 | 国电南瑞科技股份有限公司 | Line protection traveling wave distance measurement method and apparatus |
| US20210156900A1 (en) * | 2019-11-25 | 2021-05-27 | Shandong University Of Technology | Method for fault location to single-terminal traveling wave |
| CN110967599A (en) * | 2019-12-11 | 2020-04-07 | 贵州电网有限责任公司 | Electric energy quality disturbance detection and positioning algorithm |
| US20210293873A1 (en) * | 2020-03-18 | 2021-09-23 | Mitsubishi Electric Research Laboratories, Inc. | Transient based Fault Location Method for Ungrounded Power Distribution Systems |
| CN112180210A (en) * | 2020-09-24 | 2021-01-05 | 华中科技大学 | Power distribution network single-phase earth fault line selection method and system |
| CN113533849A (en) * | 2021-06-15 | 2021-10-22 | 云南电力试验研究院(集团)有限公司 | New energy station frequency modulation device anti-disturbance testing method |
| CN113945806A (en) * | 2021-11-15 | 2022-01-18 | 昆明理工大学 | Flexible direct current transmission line single-end fault location method and system |
| CN114441897A (en) * | 2021-12-31 | 2022-05-06 | 深圳供电局有限公司 | Method for identifying arrival time difference of partial discharge pulse of distribution cable line |
| CN115684830A (en) * | 2022-10-13 | 2023-02-03 | 北京四方继保工程技术有限公司 | Fault location method and system based on COMTRADE |
Non-Patent Citations (2)
| Title |
|---|
| 余本富: "基于自适应分解层数和阈值的小波去噪算法", 《传感器与微系统》, vol. 36, no. 12, pages 126 - 129 * |
| 张可: "输电线路行波测距数据的正弦拟合自动筛选方法", 《电力系统保护与控制》, vol. 43, no. 20, pages 58 - 64 * |
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