CN112327118A - Partial discharge high-frequency signal positioning method, device and medium - Google Patents
Partial discharge high-frequency signal positioning method, device and medium Download PDFInfo
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Abstract
The application relates to a method, a device and a medium for positioning a partial discharge high-frequency signal, wherein the method comprises the following steps: respectively acquiring high-frequency sampling signals at least three different measuring points with known position information in a preset coordinate space; acquiring the receiving time of each high-frequency sampling signal; and determining the position information of the partial discharge point according to the position information and the receiving time. The three-dimensional position information of partial discharge point can be accurately determined intelligently, the partial discharge source can be positioned more accurately, the working strength of high-frequency signal source detection is reduced, a scheme is provided for further overhauling, the potential insulation hazard of equipment is eliminated as early as possible, the overhauling efficiency is improved, and the safe operation level of substation equipment is improved.
Description
Technical Field
The application relates to the technical field of electrical positioning, in particular to a method, a device and a medium for positioning a partial discharge high-frequency signal.
Background
Partial discharge is one of the main factors causing insulation breakdown of electric power equipment, and is a sign of insulation aging and deterioration of the electric power equipment. If the equipment has insulation defects and is not overhauled in time, insulation breakdown and sudden power failure of the equipment can be caused finally, so that power interruption is caused, and great loss is caused. There is data indicating that 90% of power failures are initially insulation defects originating from different causes, and that almost all insulation defects induce partial discharges. Therefore, partial discharge monitoring and positioning are carried out on the operation equipment, partial discharge signals are found in time, the defects are overhauled as early as possible, and insulation breakdown faults can be effectively avoided.
The traditional partial discharge positioning system simply integrates hardware and software, has the functions of acquiring, processing and storing data of ultrahigh frequency signals in real time, is limited to two-dimensional positioning of a high-frequency signal source, and obviously has the precision of two-dimensional positioning obviously inferior to that of three-dimensional positioning. There is a need for providing a three-dimensional partial discharge high-frequency signal positioning method to more accurately position a discharge source, thereby providing a scheme for further maintenance, so as to early eliminate the insulation hidden trouble of equipment, improve maintenance efficiency, and improve the safe operation level of substation equipment.
Disclosure of Invention
Therefore, it is necessary to provide a method, an apparatus and a medium for positioning a high-frequency signal of partial discharge, which apply a three-dimensional positioning method to detect partial discharge, so as to more accurately position a discharge source and reduce the working strength of detecting a high-frequency signal source.
To achieve the above and other objects, a first aspect of the present application provides a partial discharge high-frequency signal localization method, including:
respectively acquiring high-frequency sampling signals at least three different measuring points with known position information in a preset coordinate space;
acquiring the receiving time of each high-frequency sampling signal;
and determining the position information of the partial discharge point according to the position information and the receiving time.
In the method for positioning a partial discharge high-frequency signal in the above embodiment, a three-dimensional coordinate system of a spatial region where a partial discharge point is located may be established first, then three different measurement points with known position information are selected, preferably, the three measurement points are set to be located on different planes, then high-frequency sampling signals are obtained at the three measurement points, and the receiving time of each high-frequency sampling signal is obtained; and determining the position information of the partial discharge point according to the position information and the receiving time. Since the position information, for example, coordinate information, of three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established based on the acquired reception timings of the high-frequency sampling signals of the respective measurement points, so as to calculate the three-dimensional coordinates of the partial discharge point based on the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
In one embodiment, the acquiring the receiving time of each high-frequency sampling signal includes:
for a high-frequency sampling signal of any measuring point of a measuring point, determining a shift standard waveform of the high-frequency sampling signal, shifting the high-frequency sampling signal by taking the shift standard waveform as a shift reference, superposing the shifted high-frequency sampling signal and acquiring an average high-frequency sampling signal;
determining a measuring point as a reference point and acquiring the receiving moment of a high-frequency sampling signal of the measuring point as a reference moment;
acquiring the time difference between the average high-frequency sampling signal of each measuring point and the average high-frequency sampling signal of the reference point, wherein the time difference is the time difference of the receiving time of the high-frequency sampling signals;
and determining the receiving time of each high-frequency sampling signal according to the reference time and each time difference.
In the method for positioning a partial discharge high-frequency signal in the above embodiment, for a high-frequency sampling signal obtained at any measurement point, a shift standard waveform of the high-frequency sampling signal is determined, the high-frequency sampling signal is shifted with the shift standard waveform as a shift reference, the shifted high-frequency sampling signal is superposed, and an average high-frequency sampling signal is obtained, so that horizontal shaking and random interference are eliminated to a certain extent by the obtained waveform, and the waveform is representative; the time difference between the average high-frequency sampling signal of each measuring point and the average high-frequency sampling signal of the reference point is obtained, the time difference is the time difference of the receiving time of the high-frequency sampling signals, the receiving time of each high-frequency sampling signal is determined according to the reference time and each time difference, the difficulty of obtaining the time difference of the receiving time of each high-frequency sampling signal can be reduced, the accuracy of the obtained time differences is improved, and the accuracy of the obtained position information of the partial discharge point is effectively improved.
In one embodiment, the obtaining a time difference between the average high frequency sampling signal of each measurement point and the average high frequency sampling signal of the reference point includes:
performing energy conversion on any average high-frequency sampling signal by adopting an accumulated energy method to obtain an energy accumulation curve;
the time difference is calculated by an energy-dependent search according to the energy accumulation curve.
In the method for positioning a partial discharge high-frequency signal in the above embodiment, an energy accumulation curve having a statistical significance is obtained by performing energy conversion on an average high-frequency sampling signal, and the time difference is calculated by energy correlation search according to the energy accumulation curve, so as to avoid an error caused by inflection point calculation, improve the accuracy of each obtained time difference, and effectively improve the accuracy of the obtained position information of a partial discharge point.
In one embodiment, the determining the position information of the partial discharge point according to the position information and the receiving time includes:
establishing a calculation formula of the position coordinates of the partial discharge points according to the position information and the receiving time;
and calculating the position coordinates of the partial discharge points according to the calculation formula.
In one embodiment, the calculation formula for establishing the position coordinate of the partial discharge point according to the position information and the receiving time is as follows:
in the above formula, (x, y, z) is the coordinate of the partial discharge point in the coordinate space, (x)Si,ySi,zSi) Coordinates of a log periodic antenna Si; t is the propagation time of the high-frequency signal from the partial discharge point to the reference antenna S01Is the time difference between the reception time of the high frequency sampled signal of the log periodic antenna S1 and the reception time of the high frequency sampled signal of the reference antenna S0; t is t2Is the time difference between the reception time of the high frequency sampled signal of the log periodic antenna S2 and the reception time of the high frequency sampled signal of the reference antenna S0; v. ofsI is 0, 1, 2, which is the propagation speed of the high frequency signal.
In one embodiment, the calculating the position coordinates of the partial discharge point according to the calculation formula includes:
in a Cartesian coordinate system, acquiring the distance L from a partial discharge point to a log-periodic antenna Si according to the position information and the receiving time0 kiDetermining the distance L from any search point k to log periodic antenna Si in the search spacekiEstablishing a geometric vector f0 k,fkComprises the following steps:
f0 k=(L0 k0,L0 k1,L0 k2),
fk=(Lk0,Lk1,Lk2);
the vector f is calculated according to the following formula0 k、fkEuclidean distance of (d (k)):
obtaining the coordinate value of the searching point when d (k) is minimum as the position coordinate of the partial discharge point;
wherein i is 0, 1, 2.
In one embodiment, the obtaining the high-frequency sampling signals at least three different measurement points with known position information in the preset coordinate space respectively comprises:
respectively arranging log-periodic antennas at least three different measuring points with known position information in a preset coordinate space;
and respectively acquiring high-frequency sampling signals based on the logarithmic period antennas.
A second aspect of the present application provides a partial discharge high-frequency signal positioning device, including:
the device comprises at least three log periodic antennas, a signal acquisition unit and a signal processing unit, wherein the log periodic antennas are arranged at least three different measuring points with known position information in a preset coordinate space to respectively acquire high-frequency sampling signals;
a processor, coupled to the log periodic antenna, configured to:
acquiring the receiving time of each high-frequency sampling signal;
and determining the position information of the partial discharge point according to the position information and the receiving time.
In the above-described embodiment of the local discharge high-frequency signal positioning apparatus, a three-dimensional coordinate system of a spatial region where a local discharge point is located may be established first, then three different measurement points of known position information are selected, preferably, the three measurement points are set to be located on different planes, then log-periodic antennas are set at the three measurement points, and high-frequency sampling signals of the measurement points are collected by using the log-periodic antennas; and acquiring the receiving time of each high-frequency sampling signal by using a processor so as to determine the position information of the partial discharge point according to the position information and the receiving time. Since the position information, for example, coordinate information, of three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established based on the acquired reception timings of the high-frequency sampling signals of the respective measurement points, so as to calculate the three-dimensional coordinates of the partial discharge point based on the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
A third aspect of the present application provides a partial discharge high-frequency signal positioning device including:
the high-frequency sampling signal acquisition module is used for acquiring high-frequency sampling signals at least three different measuring points with known position information in a preset coordinate space;
a signal receiving time acquisition module, configured to acquire a receiving time of each high-frequency sampling signal;
and the partial discharge point positioning module is used for determining the position information of the partial discharge point according to the position information and the receiving moment.
In the partial discharge high-frequency signal positioning apparatus in the above embodiment, the high-frequency sampling signal at the measurement point of at least three different pieces of known position information in the preset coordinate space is acquired based on the high-frequency sampling signal acquisition module, the receiving time of each high-frequency sampling signal is acquired based on the signal receiving time acquisition module, and then the position information of the partial discharge point is determined based on the partial discharge point positioning module according to the position information and the receiving time. Since the position information, for example, coordinate information, of three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established based on the acquired reception timings of the high-frequency sampling signals of the respective measurement points, so as to calculate the three-dimensional coordinates of the partial discharge point based on the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
A fourth aspect of the application provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of the method described in any one of the embodiments of the application.
In the computer-readable storage medium in the above embodiment, since the position information, for example, the coordinate information, of the three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established according to the acquired receiving time of the high-frequency sampling signal of each measurement point, so as to calculate the three-dimensional coordinates of the partial discharge point according to the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
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In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain drawings of other embodiments based on these drawings without any creative effort.
Fig. 1 is a schematic flowchart of a method for positioning a partial discharge high-frequency signal according to an embodiment of the present application;
fig. 2 is a schematic flow chart of a method for positioning a partial discharge high-frequency signal according to another embodiment of the present application;
fig. 3 is a schematic flow chart of a method for positioning a partial discharge high-frequency signal according to another embodiment of the present application;
FIG. 4 is a schematic flow chart illustrating a method for locating a partial discharge high-frequency signal according to yet another embodiment of the present application;
FIG. 5 is a schematic diagram of an experimental apparatus for positioning a partial discharge high-frequency signal according to the present disclosure;
fig. 6 is a schematic coordinate space diagram of the positioning of the partial discharge high-frequency signal built in an embodiment of the present application;
FIG. 7 is a diagram illustrating an average high frequency sampled signal obtained according to an embodiment of the present application;
fig. 8 is a schematic structural diagram of a partial discharge high-frequency signal positioning device according to an embodiment of the present application;
fig. 9 is a block diagram of a partial discharge high-frequency signal positioning apparatus according to an embodiment of the present application.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Where the terms "comprising," "having," and "including" are used herein, another element may be added unless an explicit limitation is used, such as "only," "consisting of … …," etc. Unless mentioned to the contrary, terms in the singular may include the plural and are not to be construed as being one in number.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application.
Throughout the description of the present application, it is to be noted that, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the connection may be direct or indirect via an intermediate medium, and the connection may be internal to the two components. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
Referring to fig. 1, in an embodiment of the present application, a method for locating a partial discharge high-frequency signal is provided, which includes the following steps:
and step 26, determining the position information of the partial discharge point according to the position information and the receiving time.
As an example, a three-dimensional coordinate system of a space region where a partial discharge point is located may be established, then three different measurement points with known position information are selected, preferably, the three measurement points are set to be located on different planes, then high-frequency sampling signals are obtained at the three measurement points, and the receiving time of each high-frequency sampling signal is obtained; and determining the position information of the partial discharge point according to the position information and the receiving time. Since the position information, for example, coordinate information, of three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established based on the acquired reception timings of the high-frequency sampling signals of the respective measurement points, so as to calculate the three-dimensional coordinates of the partial discharge point based on the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
As an example, in an embodiment of the present application, the respectively acquiring high-frequency sampling signals at least three different measurement points with known position information in a preset coordinate space may include:
respectively arranging log-periodic antennas at least three different measuring points with known position information in a preset coordinate space;
and respectively acquiring high-frequency sampling signals based on the logarithmic period antennas.
Specifically, the log periodic antenna has no amplification filter, and the gain is larger than that of a general antenna, so that the log periodic antenna can be better applied to partial discharge signal acquisition. According to the method, through designing a log periodic antenna model, defining material types, setting boundary conditions and port excitation, solving and setting are carried out, and the standing-wave ratio of the log periodic antenna is derived. And determining the position of a feed point of the log-periodic antenna, the thickness of the dielectric plate and the attachment material by using a control variable method, and designing the log-periodic antenna with optimal performance so as to better complete the detection of partial discharge.
Referring to fig. 2, in an embodiment of the present application, the acquiring the receiving time of each high-frequency sampling signal includes:
As an example, for a high-frequency sampling signal acquired at any measuring point, a shift standard waveform of the high-frequency sampling signal is determined, the high-frequency sampling signal is shifted by taking the shift standard waveform as a shift reference, the shifted high-frequency sampling signal is superposed, and an average high-frequency sampling signal is acquired, so that the obtained waveform eliminates horizontal shaking and random interference to a certain extent and is representative; the time difference between the average high-frequency sampling signal of each measuring point and the average high-frequency sampling signal of the reference point is obtained, the time difference is the time difference of the receiving time of the high-frequency sampling signals, the receiving time of each high-frequency sampling signal is determined according to the reference time and each time difference, the difficulty of obtaining the time difference of the receiving time of each high-frequency sampling signal can be reduced, the accuracy of the obtained time differences is improved, and the accuracy of the obtained position information of the partial discharge point is effectively improved.
Referring to fig. 3, in an embodiment of the present application, the obtaining a time difference between the average high frequency sampling signal of each measurement point and the average high frequency sampling signal of the reference point includes:
As an example, an energy accumulation curve having a statistical significance is obtained by performing energy conversion on an average high-frequency sampling signal, and the time difference is calculated by energy correlation search according to the energy accumulation curve, so as to avoid an error caused by inflection point calculation, and improve the accuracy of each obtained time difference, so as to effectively improve the accuracy of the obtained position information of the partial discharge point.
Referring to fig. 4, in an embodiment of the present application, the determining the location information of the partial discharge point according to the location information and the receiving time includes:
and step 264, calculating the position coordinates of the partial discharge points according to the calculation formula.
Specifically, the calculation formula for establishing the position coordinates of the partial discharge point according to the position information and the receiving time is as follows:
in the above formula, (x, y, z) is the coordinate of the partial discharge point in the coordinate space, (x)Si,ySi,zSi) Coordinates of a log periodic antenna Si; t is the propagation time of the high-frequency signal from the partial discharge point to the reference antenna S01Is the time difference between the reception time of the high frequency sampled signal of the log periodic antenna S1 and the reception time of the high frequency sampled signal of the reference antenna S0; t is t2Is the time difference between the reception time of the high frequency sampled signal of the log periodic antenna S2 and the reception time of the high frequency sampled signal of the reference antenna S0; v. ofsI is 0, 1, 2, which is the propagation speed of the high frequency signal.
Specifically, in one embodiment of the present application, the calculating the position coordinates of the partial discharge point according to the calculation formula includes:
in a Cartesian coordinate system, partial discharge is obtained according to the position information and the receiving timeDistance L from point to log periodic antenna Si0 kiDetermining the distance L from any search point k to log periodic antenna Si in the search spacekiEstablishing a geometric vector f0 k,fkComprises the following steps:
f0 k=(L0 k0,L0 k1,L0 k2),
fk=(Lk0,Lk1,Lk2);
the vector f is calculated according to the following formula0 k、fkEuclidean distance of (d (k)):
obtaining the coordinate value of the searching point when d (k) is minimum as the position coordinate of the partial discharge point;
wherein i is 0, 1, 2.
Aiming at the technical scheme in the embodiment, a laboratory partial discharge test platform is built, a three-dimensional space of a transformer substation is designed, and the simulation size is 9 multiplied by 10 multiplied by 9m3Referring to fig. 5, fig. 5 is a wiring diagram illustrating a partial discharge ultrahigh frequency measurement experiment, wherein a step-up transformer is composed of an auto-transformer and a no-corona test transformer; the protective resistor R plays a role in current limiting protection; the coupling capacitor is a 2000pF high-voltage coupling capacitor, has the withstand voltage of 50kV, and is used for coupling the local discharge pulse current generated by the test article. In fig. 5, after the log periodic antenna 12 is used to obtain the high-frequency sampling signal, the high-frequency sampling signal is processed by an amplifier and then is connected to the oscilloscope 13 through a 50 ohm coaxial cable with a length of 6 m. In the experiment, signals of four paths of log periodic antennas 12 are collected simultaneously, the sampling rate is 5GS/s, and the triggering time is 100 ns.
Referring to fig. 5, the oscilloscope has four channels, and can acquire four signals simultaneously. The method includes the steps that 4 log periodic antennas 12 are arranged in a three-dimensional space of an analog substation, for example, from A to D, specific installation positions are A (1.2, 8.8 and 3.75), B (4.5, 8.8 and 3.75), C (7.8, 8.8 and 3.75) and D (4.5, 6.5 and 2), and the unit is m, wherein the position O (4.5, 1.2 and 3.75) of a partial discharge point is located.
With the increase of the number of samples, the actually measured time difference is closer to a theoretical value, so that the higher positioning precision can be achieved by generally selecting 20-30 samples for calculation, and the number of the selected samples in the experiment is 20.
In n samples collected by a log periodic antenna, if the similarity between the kth waveform sample and other waveforms is the best, the waveform can be considered to reflect the discharge characteristic most and the interference is the minimum, and the sample is taken as a shift standard to calculate the time difference. Shifting refers to changing the relative distance between a selected waveform sample and other waveform samples until the cross-correlation function of the two waveforms is maximized, and then adding the two waveforms to obtain an average waveform. The waveform thus obtained is representative in that horizontal shaking and random interference are eliminated to some extent. And then the obtained waveform is used for energy accumulation calculation, and the obtained accumulated energy curve has statistical significance.
The waveform after superposition averaging of each channel is used for obtaining the time difference between the two waveforms by an energy correlation search method. The 20 sample waveforms collected in the experiment are subjected to a "correlation-shift-superposition" mathematical transformation, resulting in a waveform diagram as shown in fig. 7. The time difference of the waveforms of the partial discharge points between the antennas in each logarithmic period of the electrical equipment measured by the ultrahigh frequency method is often nanosecond or even picosecond, and the requirement on the precision of time delay is very high. Therefore, the energy accumulation method is adopted to convert the measured signal waveform data of the partial discharge point to obtain an energy accumulation curve, and the time difference is obtained through energy correlation search so as to avoid the error caused by inflection point calculation. Determining the time difference by adopting an energy correlation search method, taking s2 as a reference signal, and calculating the time difference result by using an experimental acquisition signal as follows:
τAB=2.29ns,τCB=2.29ns,τDB=-6.73ns。
the method adopts a space search method to position the partial discharge point, and the algorithm is as follows: assume that the signal arrives at the log periodic antenna in a straight path. Let the coordinates of the discharge point be (x, y, z), log-periodic antenna SiThe coordinate of (i ═ 0, 1, 2, 3) is (x)Si,ySi,zSi) The propagation equation of the discharge signal in the uniform medium space is:
in the above formula, t is the arrival of the high frequency signal from the partial discharge point to the log periodic antenna S0Propagation time of τ0iIs a log periodic antenna S0And SiTime delay between received signals, vsIs the propagation speed of high frequency signals in the medium. Time difference tau01,τ02,τ03Can be obtained by measurement calculation. The least square method is long in time consumption for solving the equation set, and the situation of no solution is often generated. Therefore, the space search algorithm is designed to quickly locate the partial discharge point, namely the fault source, the search speed is high, the equation set does not need to be solved, and the defect that the common space geometric location algorithm is not sufficient in solution is overcome.
The space search algorithm is to divide the search space into grids as shown in fig. 6 in a cartesian coordinate system. Then, assuming that the discharge sources are sequentially arranged on grid points k generated by division, if the discharge sources obtained by calculation according to actual measurement time delay are arranged on different log-periodic antennas SiIs a distance L0 ki( i 1, 2, 3) and any search point k is from log periodic antenna SiIs a distance Lki(i ═ 1, 2, 3), respectively, creating a geometric vector f0 k,fk:
fk=(Lk1,Lk2,Lk3)
The vector f is foundk 0,fkThe Euclidean distance of (A) is:
when d (k) is minimal, i.e. fk 0And fkThe distance is the shortest, and the searching point can be determined as the position closest to the actual partial discharge point, namely the discharge source. And taking the log periodic antenna B as a reference log periodic antenna, wherein the theoretical time difference calculation result is as follows: tau isAB=2.29ns,τCB=2.29ns,τDB-6.68 ns. Vector fk 0,fkThe Euclidean distance d (k) is expressed by a one-dimensional array, the minimum value of d (k) is 0.145, and the output result of the positioning program of the position of the partial discharge point (namely the position of the curve minimum corresponding to the space position) is (4.30, 1.15, 3.75) m. The position of the partial discharge point is very close to the position of O (4.5, 1.2, 3.8) m, and the positioning effect is ideal.
In the experimental calculation process, the position of a partial discharge point is positioned by adopting a space search method, and a vector fk 0,fkThe Euclidean distance d (k) is expressed by a one-dimensional array, the minimum value of d (k) is 0.102, the output result of the positioning program of the position of the partial discharge point (namely the position of the space corresponding to the minimum value of the curve) is (4.25, 1.05, 3.85) m, the position is closer to the position O (4.5, 1.2, 3.75) m of the partial discharge point, and the positioning effect is more ideal.
The following table 1 is a comparison result of theoretical results and test results, and it can be known that the maximum errors of the positioning results are all about 0.25m, so that the effectiveness of the positioning algorithm is proved. The accuracy of the time delay is very important, and the positioning result is greatly influenced. The space search method can accurately position the actual discharge source, greatly shortens the positioning time and avoids the situation of no solution.
TABLE 1
Referring to fig. 8, in an embodiment of the present application, a partial discharge high-frequency signal positioning apparatus 100 is provided, which includes at least three log periodic antennas 12 and a processor 14, where the number of the log periodic antennas 12 is at least three, and the log periodic antennas are used to be disposed at least three different measurement points with known position information in a preset coordinate space to respectively obtain high-frequency sampling signals; a processor 14 is connected to the log periodic antenna 12, the processor 14 being configured to:
acquiring the receiving time of each high-frequency sampling signal;
and determining the position information of the partial discharge point according to the position information and the receiving time.
Specifically, please continue to refer to fig. 8, a three-dimensional coordinate system of a spatial region where the partial discharge point is located may be established first, then three different measurement points with known position information are selected, preferably, the three measurement points are set to be located on different planes, then the log periodic antenna 12 is set at the three measurement points, and the log periodic antenna 12 is utilized to collect high-frequency sampling signals of the measurement points; and acquiring the receiving time of each high-frequency sampling signal by using the processor 14 to determine the position information of the partial discharge point according to the position information and the receiving time. Since the position information, for example, coordinate information, of three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established based on the acquired reception timings of the high-frequency sampling signals of the respective measurement points, so as to calculate the three-dimensional coordinates of the partial discharge point based on the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
Referring to fig. 9, in an embodiment of the present application, a partial discharge high-frequency signal positioning apparatus 200 is provided, which includes a high-frequency sampling signal obtaining module 202, a signal receiving time obtaining module 204, and a partial discharge point positioning module 206, wherein the high-frequency sampling signal obtaining module 202 is configured to obtain high-frequency sampling signals at least three different measurement points with known position information in a preset coordinate space; the signal receiving time acquiring module 204 is configured to acquire a receiving time of each high-frequency sampling signal; the partial discharge point positioning module 206 is configured to determine the position information of the partial discharge point according to the position information and the receiving time.
Specifically, with reference to fig. 9, the high-frequency sampling signal obtaining module 202 obtains high-frequency sampling signals at least three different measurement points with known position information in a preset coordinate space, the signal receiving time obtaining module 204 obtains receiving times of the high-frequency sampling signals, and the partial discharge point positioning module 206 determines position information of a partial discharge point according to the position information and the receiving times. Since the position information, for example, coordinate information, of three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established based on the acquired reception timings of the high-frequency sampling signals of the respective measurement points, so as to calculate the three-dimensional coordinates of the partial discharge point based on the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
For the specific definition of the partial discharge high-frequency signal positioning device, reference may be made to the above definition of the partial discharge high-frequency signal positioning method, which is not described herein again.
In an embodiment of the application, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, realizes the steps of the method as described in any of the embodiments of the application.
In the computer-readable storage medium in the above embodiment, since the position information, for example, the coordinate information, of the three different measurement points located in the coordinate space where the partial discharge point is located is known, a mathematical expression for calculating the three-dimensional coordinates of the partial discharge point may be established according to the acquired receiving time of the high-frequency sampling signal of each measurement point, so as to calculate the three-dimensional coordinates of the partial discharge point according to the mathematical expression, thereby determining the position information of the partial discharge point. The three-dimensional position information of the partial discharge point can be intelligently and accurately determined, the partial discharge source can be more accurately positioned, and the working strength of high-frequency signal source detection is reduced, so that a scheme is provided for further overhauling, the insulation hidden danger of equipment is eliminated as soon as possible, the overhauling efficiency is improved, and the safe operation level of the substation equipment is improved.
It should be understood that although the various steps in the flowcharts of fig. 1-4 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, although at least some of the steps in fig. 1-4 may include multiple sub-steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or alternatingly with other steps or at least some of the sub-steps or stages of other steps.
All or part of each module in the partial discharge high-frequency signal positioning device can be realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A method for locating a partial discharge high-frequency signal, comprising:
respectively acquiring high-frequency sampling signals at least three different measuring points with known position information in a preset coordinate space;
acquiring the receiving time of each high-frequency sampling signal;
and determining the position information of the partial discharge point according to the position information and the receiving time.
2. The method of claim 1, wherein said obtaining a receive time instant of each of said high frequency sampled signals comprises:
for a high-frequency sampling signal of any measuring point, determining a shift standard waveform of the high-frequency sampling signal, shifting the high-frequency sampling signal by taking the shift standard waveform as a shift reference, superposing the shifted high-frequency sampling signal, and acquiring an average high-frequency sampling signal;
determining a measuring point as a reference point and acquiring the receiving moment of a high-frequency sampling signal of the measuring point as a reference moment;
acquiring the time difference between the average high-frequency sampling signal of each measuring point and the average high-frequency sampling signal of the reference point, wherein the time difference is the time difference of the receiving time of the high-frequency sampling signals;
and determining the receiving time of each high-frequency sampling signal according to the reference time and each time difference.
3. The method of claim 2, wherein the obtaining a time difference between the average high frequency sampled signal for each measurement point and the average high frequency sampled signal for the reference point comprises:
performing energy conversion on any average high-frequency sampling signal by adopting an accumulated energy method to obtain an energy accumulation curve;
the time difference is calculated by an energy-dependent search according to the energy accumulation curve.
4. The method according to claim 2 or 3, wherein the determining the position information of the partial discharge point according to the position information and the receiving time comprises:
establishing a calculation formula of the position coordinates of the partial discharge points according to the position information and the receiving time;
and calculating the position coordinates of the partial discharge points according to the calculation formula.
5. The method according to claim 4, wherein the calculation formula for establishing the position coordinates of the partial discharge point according to the position information and the receiving time is as follows:
in the above formula, (x, y, z) is the coordinate of the partial discharge point in the coordinate space, (x)Si,ySi,zSi) Coordinates of a log periodic antenna Si; t is the propagation time of the high-frequency signal from the partial discharge point to the reference antenna S01Is the time difference between the reception time of the high frequency sampled signal of the log periodic antenna S1 and the reception time of the high frequency sampled signal of the reference antenna S0; t is t2Is the time difference between the reception time of the high frequency sampled signal of the log periodic antenna S2 and the reception time of the high frequency sampled signal of the reference antenna S0; v. ofsI is 0, 1, 2, which is the propagation speed of the high frequency signal.
6. The method of claim 5, wherein said calculating the position coordinates of the partial discharge point according to the calculation formula comprises:
in a Cartesian coordinate system, acquiring the distance L from a partial discharge point to a log-periodic antenna Si according to the position information and the receiving time0 kiDetermining the distance L from any search point k to log periodic antenna Si in the search spacekiEstablishing a geometric vector f0 k,fkComprises the following steps:
f0 k=(L0 k0,L0 k1,L0 k2),
fk=(Lk0,Lk1,Lk2);
the vector f is calculated according to the following formula0 k、fkEuclidean distance of (d (k)):
obtaining the coordinate value of the searching point when d (k) is minimum as the position coordinate of the partial discharge point;
wherein i is 0, 1, 2.
7. The method of claim 5, wherein the acquiring the high frequency sampling signals at least three different measurement points with known position information in the preset coordinate space respectively comprises:
respectively arranging log-periodic antennas at least three different measuring points with known position information in a preset coordinate space;
and respectively acquiring high-frequency sampling signals based on the logarithmic period antennas.
8. A partial discharge high-frequency signal locating device, comprising:
the device comprises at least three log periodic antennas, a signal acquisition unit and a signal processing unit, wherein the log periodic antennas are arranged at least three different measuring points with known position information in a preset coordinate space to respectively acquire high-frequency sampling signals;
a processor, coupled to the log periodic antenna, configured to:
acquiring the receiving time of each high-frequency sampling signal;
and determining the position information of the partial discharge point according to the position information and the receiving time.
9. A partial discharge high-frequency signal locating device, comprising:
the high-frequency sampling signal acquisition module is used for acquiring high-frequency sampling signals at least three different measuring points with known position information in a preset coordinate space;
a signal receiving time acquisition module, configured to acquire a receiving time of each high-frequency sampling signal;
and the partial discharge point positioning module is used for determining the position information of the partial discharge point according to the position information and the receiving moment.
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 method of any one of claims 1 to 7.
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