CN115856723A - Transformer winding state monitoring method and device and storage medium - Google Patents

Transformer winding state monitoring method and device and storage medium Download PDF

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CN115856723A
CN115856723A CN202211144447.7A CN202211144447A CN115856723A CN 115856723 A CN115856723 A CN 115856723A CN 202211144447 A CN202211144447 A CN 202211144447A CN 115856723 A CN115856723 A CN 115856723A
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frequency
signal
transformer
response
moment
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蔡玲珑
马志钦
林春耀
靳宇晖
姜烁
周丹
舒想
杨贤
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Guangdong Power Grid Co Ltd
Electric Power Research Institute of Guangdong Power Grid Co Ltd
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Guangdong Power Grid Co Ltd
Electric Power Research Institute of Guangdong Power Grid Co Ltd
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Abstract

The invention discloses a method and a device for monitoring the state of a transformer winding and a storage medium, wherein the method comprises the following steps: the method comprises the steps that a transformer is equivalent to a two-port network, a first excitation signal is injected into one end of the transformer, and a first response signal causing oscillation of the two-port network is detected at the other end of the transformer; transforming the first excitation signal into a second excitation signal and the first response signal into a second response signal by time-frequency transformation; calculating a winding frequency response in a frequency domain according to the second excitation signal and the second response signal, and drawing a frequency response amplitude spectrum according to the winding frequency response; performing discrete Fourier transform on the discrete time sequence at the nth moment to obtain a frequency spectrum value at the nth moment; and calculating to obtain the frequency spectrum value at the n +1 th moment according to the frequency spectrum value at the n th moment and the discrete time sequence at the n +1 th moment, and judging the state of the transformer winding according to the frequency spectrum value. The invention can effectively improve the efficiency of monitoring the state of the transformer winding.

Description

Transformer winding state monitoring method and device and storage medium
Technical Field
The invention relates to the technical field of power equipment, in particular to a transformer winding state monitoring method, a transformer winding state monitoring device and a storage medium.
Background
At present, with the large-scale construction and popularization of ultrahigh voltage engineering in China, higher requirements on power supply reliability are put forward while the capacity of a power grid is improved. As a key junction device of a power system, the operation state of a large-scale transformer is directly related to the operation reliability and stability of a power grid. Because the transformer is connected with power grids with different voltage grades, if the transformer fails, major power accidents such as voltage fluctuation, equipment damage, large-area power failure and the like can be caused, and serious economic loss and social influence are caused.
Because the transformer fault conditions are different, the distinguishing method is also different: the transformer faults include overheating faults, insulation faults, mechanical faults, and the like, distinguished by type. The transformer faults are distinguished from the internal structure, the transformer faults comprise winding faults, iron core faults and accessory faults, the fault conditions of the transformer can be known through statistics and analysis, the transformer faults are not directly generated by overheating and insulation problems but are overheating faults and insulation faults caused by mechanical defects, the winding faults are more in the mechanical defects of the transformer, and the threat in the operation of the transformer is the greatest. According to the statistics of the number of the transformer faults in the power grid, in 1999-2003, about 72 transformers have damage accidents caused by impact of short-circuit current on windings of the transformers with the voltage class of more than 110kV in China, and the percentage of the total number of the transformer faults is more than 27%. According to the statistical analysis conditions of power accidents of 220kV and above transformers in 2005 such as accidental shutdown, the percentage of accidental shutdown time caused by faults such as winding deformation and looseness in the 220kV power grid transformer exceeds 79%, the percentage of accidental shutdown time in the 330kV power grid transformer exceeds 72%, and the percentage of accidental shutdown time in the 500kV power grid transformer is close to 99%. Moreover, a transformer fault analysis of 2000-2012 by manufacturing enterprises and national grid companies shows that the proportion of faults caused by winding deformation in the total accident rate of the transformer is more than half. In order to ensure the stable operation of the transformer, it is necessary to develop a research on the evaluation, diagnosis and prediction method of the transformer winding state.
The existing transformer winding monitoring method usually adopts a Frequency Response analysis method (FRA), but the existing transformer winding detection method adopts a Fast Fourier Transform (FFT) algorithm to obtain a Frequency spectrum value, and needs to perform multiple fourier transforms, so that the efficiency of monitoring the state of the transformer winding is low.
Disclosure of Invention
The invention provides a transformer winding monitoring method, which aims to solve the technical problem that the existing transformer winding monitoring method usually adopts a frequency response analysis method to monitor a transformer winding, but the existing transformer winding monitoring method adopts a fast Fourier transform algorithm to obtain a frequency spectrum value, needs to perform Fourier transform for many times and has lower efficiency in monitoring the state of the transformer winding.
One embodiment of the present invention provides a method for monitoring a state of a transformer winding, including:
the method comprises the steps of enabling a transformer to be equivalent to a two-port network, injecting a first excitation signal into one end of the transformer, and detecting a first response signal which causes oscillation of the two-port network at the other end of the transformer;
transforming the first excitation signal into a second excitation signal and the first response signal into a second response signal by time-frequency transformation;
calculating a winding frequency response in a frequency domain according to the second excitation signal and the second response signal, and drawing a frequency response amplitude spectrum according to the winding frequency response;
performing discrete Fourier transform on the discrete time sequence at the nth moment in the frequency response amplitude spectrum to obtain a frequency spectrum value at the nth moment;
and acquiring the discrete time sequence of the n +1 moment, calculating to obtain the frequency spectrum value of the n +1 moment according to the frequency spectrum value of the n moment and the discrete time sequence of the n +1 moment, and judging the state of the transformer winding according to the frequency spectrum value.
Further, the transforming the first excitation signal into a second excitation signal and the transforming the first response signal into a second response signal by time-frequency transformation includes:
Figure SMS_1
Figure SMS_2
wherein, U i (n) is a first excitation signal, U o (n) is the first response signal, U i (k) Is the second excitation signal, U o (k) Is a second response signal, N is a time series index, N =0,1, \8230;, N-1; k is more than or equal to 0 and less than or equal to N-1; n is the number of sampling points of the signal, k is the index of the frequency spectrum sequence, and j is an imaginary unit.
Further, said calculating a winding frequency response in the frequency domain from said second excitation signal and said second response signal comprises:
Figure SMS_3
where H (f) is the winding frequency response.
Further, the performing discrete fourier transform on the discrete time sequence at the nth time in the frequency response magnitude spectrum to obtain a spectrum value at the nth time includes:
Figure SMS_4
wherein, X n (k) The spectrum value of the k-th frequency point obtained by the discrete Fourier transform at the nth time is shown, M is a time sequence index, and M =0,1, \8230;, M-1; m is the number of sample points of the signal, k is the spectral sequence index, q represents the number of window function slips, q =0,1,2,3, \8230;, and q = n-M +1.
Further, the calculating the spectrum value at the n +1 th time according to the spectrum value at the n th time and the discrete time sequence at the n +1 th time includes:
and adding the frequency spectrum value at the nth moment and the sampling signal value of the discrete time sequence at the (n + 1) th moment, subtracting the sampling signal values before the M moments, and then carrying out phase shift to obtain the frequency spectrum value at the (n + 1) th moment.
One embodiment of the present invention provides a transformer winding state monitoring apparatus, including:
the signal acquisition module is used for enabling a transformer to be equivalent to a two-port network, injecting a first excitation signal into one end of the transformer, and detecting a first response signal causing oscillation of the two-port network at the other end of the transformer;
the signal conversion module is used for converting the first excitation signal into a second excitation signal and converting the first response signal into a second response signal through time-frequency conversion;
the frequency response amplitude spectrum drawing module is used for calculating the winding frequency response in a frequency domain according to the second excitation signal and the second response signal and drawing a frequency response amplitude spectrum according to the winding frequency response;
the discrete Fourier transform module is used for performing discrete Fourier transform on the discrete time sequence at the nth moment in the frequency response amplitude spectrum to obtain a frequency spectrum value at the nth moment;
and the transformer winding state monitoring module is used for acquiring the discrete time sequence at the moment n +1, calculating to obtain the frequency spectrum value at the moment n +1 according to the frequency spectrum value at the moment n and the discrete time sequence at the moment n +1, and judging the transformer winding state according to the frequency spectrum value.
Further, the signal conversion module is further configured to:
Figure SMS_5
Figure SMS_6
wherein, U i (n) is a first excitation signal, U o (n) is the first response signal, U i (k) Is a second excitation signal, U o (k) N is a time series index, N =0,1, \8230; \ 8230, N-1; k is more than or equal to 0 and less than or equal to N-1; n is the number of sampling points of the signal, k is the index of the frequency spectrum sequence, and j is an imaginary unit.
Further, the frequency response magnitude spectrum drawing module is further configured to:
Figure SMS_7
where H (f) is the winding frequency response.
Further, the fourier transform module is further configured to:
Figure SMS_8
wherein, X n (k) The spectrum value of the k-th frequency point obtained by the discrete Fourier transform at the nth time is shown, M is a time sequence index, and M =0,1, \8230;, M-1; m is the number of samples of the signal, k is the spectral sequence index, q represents the number of window function slips, q =0,1,2,3, \ 8230;, and q = n-M +1.
An embodiment of the present invention provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program runs, a device on which the computer-readable storage medium is located is controlled to execute the transformer winding state monitoring method as described above.
In the embodiment of the invention, for the frequency spectrum values of two continuous moments, after the frequency spectrum value of the previous moment is known, the frequency spectrum value of the current moment can be quickly obtained through the recursion operation of the embodiment of the invention, the frequency spectrum value of the current moment can be obtained without carrying out discrete Fourier transform calculation for many times, and the frequency spectrum value of the current moment can be quickly obtained through calculation according to the frequency spectrum value of the previous moment, so that the frequency spectrum value can be obtained in real time, the calculated amount of the frequency spectrum value can be effectively reduced, and the efficiency of monitoring the state of the transformer winding can be improved.
Drawings
Fig. 1 is a schematic flow chart of a method for monitoring a state of a transformer winding according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a two-port network according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a transformer winding state monitoring device according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.
In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, 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; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. 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, an embodiment of the present invention provides a method for monitoring a state of a transformer winding, including:
s1, a transformer is equivalent to a two-port network, a first excitation signal is injected into one end of the transformer, and a first response signal causing the two-port network to oscillate is detected at the other end of the transformer;
referring to fig. 2, in a high frequency state, i.e. when the frequency is greater than 1kHz, the iron core of the transformer can be almost ignored due to the skin effect, and the transformer is equivalent to a two-port network formed by a resistor, an inductor and a capacitor. Referring to fig. 2, the two-port network structure of the embodiment of the present invention includes a transformer housing, a high-voltage winding, a low-voltage winding, and an iron core, wherein one end of the high-voltage winding is connected to the transformer housing, the other end of the high-voltage winding is connected to one end of the low-voltage winding in series, and one end of the low-voltage winding is connected to the iron core. Wherein, C hg 、C lg Capacitance, L, to ground (transformer housing) of the high and low voltage windings, respectively h And L l Equivalent inductances, C, of the high-voltage winding and the low-voltage winding, respectively hl For equivalent capacitance between the high-voltage winding and the low-voltage winding, C sh And C sl Respectively, the inter-cake capacitance of the high-voltage winding and the low-voltage winding. When the winding is deformed or short-circuited, the change of the resistive, inductive or capacitive parameters in the two-port network can be corresponded to, and finally reflected in the frequency spectrumIn the curve, the deviation of the frequency response curve is shown, and whether the health state of the winding changes or not can be accurately judged according to the trend change of the frequency response curve.
According to the embodiment of the invention, a signal is coupled into a winding through a sensor arranged at the outlet of a bushing, a first excitation signal with relatively high voltage copy and rich in high-frequency signal components is injected into one side of a transformer, a detector at the other end of the transformer causes a first response signal of two-port network oscillation, and the first excitation signal and the first response signal are both time-domain signals.
S2, converting the first excitation signal into a second excitation signal and converting the first response signal into a second response signal through time-frequency conversion;
in the embodiment of the present invention, the first excitation signal and the second response signal are transformed into the second excitation signal and the second response signal through time-frequency transformation, where the second excitation signal and the second response signal are both frequency domain signals.
S3, calculating a winding frequency response in a frequency domain according to the second excitation signal and the second response signal, and drawing a frequency response amplitude spectrum according to the winding frequency response;
s4, performing discrete Fourier transform on the discrete time sequence at the nth moment in the frequency response amplitude spectrum to obtain a frequency spectrum value at the nth moment;
s5, obtaining the discrete time sequence of the n +1 moment, calculating according to the frequency spectrum value of the nth moment and the discrete time sequence of the n +1 moment to obtain the frequency spectrum value of the n +1 moment, and judging the winding state of the transformer according to the frequency spectrum value.
In the embodiment of the invention, for the frequency spectrum values of two continuous moments, after the frequency spectrum value of the previous moment is known, the frequency spectrum value of the current moment can be quickly obtained through the recursion operation of the embodiment of the invention, so that the calculated amount of the frequency spectrum value can be effectively reduced, and the efficiency of monitoring the state of the transformer winding can be effectively improved.
In the embodiment of the invention, the state of the transformer winding is judged according to the frequency spectrum value as follows: and drawing a frequency spectrum curve according to the frequency spectrum value, and judging whether the state of the transformer winding is healthy or not according to the deviation of the frequency spectrum curve.
In one embodiment, transforming the first excitation signal into the second excitation signal and the first response signal into the second response signal by time-frequency transformation comprises:
Figure SMS_9
Figure SMS_10
wherein, U i (n) is a first excitation signal, U o (n) is the first response signal, U i (k) Is the second excitation signal, U o (k) Is a second response signal, N is a time series index, N =0,1, \8230;, N-1; k is more than or equal to 0 and less than or equal to N-1; n is the number of sampling points of the signal, k is the index of the frequency spectrum sequence, and j is an imaginary unit.
In one embodiment, calculating a winding frequency response in the frequency domain from the second excitation signal and the second response signal comprises:
Figure SMS_11
where H (f) is the winding frequency response.
In the embodiment of the invention, H (f) is the winding frequency response, and H (f) is a phasor, and in application, the amplitude | H (f) | of the frequency point corresponding to H (f) is only taken to draw a frequency response amplitude spectrum.
In one embodiment, performing a discrete fourier transform on a discrete-time sequence at an nth time in a frequency response magnitude spectrum to obtain a spectral value at the nth time comprises:
Figure SMS_12
wherein, X n (k) The method comprises the steps of representing a frequency spectrum value of a kth frequency point obtained by performing discrete Fourier transform at the nth time, wherein M is a time series index, and M =0,1, \8230;, M-1; m is letterThe number of sampling points of the number, k is the spectral sequence index, q represents the number of window function slips, q =0,1,2,3, \ 8230;, and q = n-M +1.
In the embodiment of the invention, the frequency spectrum value at the nth moment can be quickly obtained in real time through sliding discrete Fourier transform according to the second excitation signal and the second response signal of the frequency domain, so that the state of the transformer winding can be quickly monitored according to the frequency spectrum value.
In one embodiment, calculating the spectral value at the n +1 th time instant according to the spectral value at the n th time instant and the discrete time sequence at the n +1 th time instant includes:
and adding the frequency spectrum value at the nth moment and the sampling signal value of the discrete time sequence at the (n + 1) th moment, subtracting the sampling signal values before the M moments, and then carrying out phase shift to obtain the frequency spectrum value at the (n + 1) th moment.
In this embodiment of the present invention, at time n +1, the frequency spectrum value of the kth frequency point of the M-point DFT in the sliding window is:
Figure SMS_13
namely:
Figure SMS_14
as can be seen from the above calculation formula, the discrete Fourier transform result at the n +1 th time is the discrete Fourier transform result X at the previous time n (k) Adding the current sampling signal value, subtracting the sampling signal values before M moments, and then performing phase shift to obtain the phase-shifted signal.
The embodiment of the invention has the following beneficial effects:
in the embodiment of the invention, for the frequency spectrum values of two continuous moments, after the frequency spectrum value of the previous moment is known, the frequency spectrum value of the current moment can be quickly obtained through the recursion operation of the embodiment of the invention, the frequency spectrum value is obtained without performing discrete Fourier transform calculation for many times, and the frequency spectrum value of the current moment is quickly obtained through calculation according to the frequency spectrum value of the previous moment, so that the frequency spectrum value can be obtained in real time, the calculated amount of the frequency spectrum value can be effectively reduced, and the efficiency of monitoring the state of the transformer winding is improved.
Referring to fig. 3, based on the same inventive concept as the above embodiment, an embodiment of the present invention provides a transformer winding state monitoring apparatus, including:
a signal obtaining module 10, configured to equate the transformer to a two-port network, inject a first excitation signal into one end of the transformer, and detect a first response signal that causes oscillation of the two-port network at the other end of the transformer;
a signal transformation module 20, configured to transform the first excitation signal into a second excitation signal and transform the first response signal into a second response signal through time-frequency transformation;
a frequency response amplitude spectrum drawing module 30, configured to calculate a winding frequency response in the frequency domain according to the second excitation signal and the second response signal, and draw a frequency response amplitude spectrum according to the winding frequency response;
the discrete fourier transform module 40 is configured to perform discrete fourier transform on the discrete time sequence at the nth time in the frequency response amplitude spectrum to obtain a spectrum value at the nth time;
and the transformer winding state monitoring module 50 is configured to acquire the discrete time sequence at the n +1 moment, calculate a frequency spectrum value at the n +1 moment according to the frequency spectrum value at the n moment and the discrete time sequence at the n +1 moment, and judge the state of the transformer winding according to the frequency spectrum value.
In one embodiment, the signal transformation module 20 is further configured to:
Figure SMS_15
Figure SMS_16
wherein, U i (n) is a first excitation signal, U o (n) is the first response signal, U i (k) Is a second excitation signal, U o (k) Is a second response signal, N is a time series index, N =0,1, \8230;, N-1; k is more than or equal to 0 and less than or equal to N-1; n is the number of sampling points of the signal, k is the index of the frequency spectrum sequence, and j is an imaginary unit.
In one embodiment, the frequency response magnitude spectrum drawing module 30 is further configured to:
Figure SMS_17
where H (f) is the winding frequency response.
In one embodiment, the fourier transform module 40 is further configured to:
Figure SMS_18
wherein, X n (k) The method comprises the steps of representing a frequency spectrum value of a kth frequency point obtained by performing discrete Fourier transform at the nth time, wherein M is a time series index, and M =0,1, \8230;, M-1; m is the number of sampling points of the signal, k is the spectral sequence index, q represents the number of window function slips, q =0,1,2,3, \ 8230;, and q = n-M +1.
In one embodiment, the calculating the spectral value at the n +1 th time point according to the spectral value at the n th time point and the discrete time sequence at the n +1 th time point includes:
and adding the frequency spectrum value at the nth moment and the sampling signal value of the discrete time sequence at the (n + 1) th moment, subtracting the sampling signal values before the M moments, and then carrying out phase shift to obtain the frequency spectrum value at the (n + 1) th moment.
An embodiment of the present invention provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program runs, the apparatus in which the computer-readable storage medium is located is controlled to execute the transformer winding state monitoring method as described above.
The foregoing is a preferred embodiment of the present invention, and it should be noted that it would be apparent to those skilled in the art that various modifications and enhancements can be made without departing from the principles of the invention, and such modifications and enhancements are also considered to be within the scope of the invention.

Claims (10)

1. A method of monitoring a condition of a transformer winding, comprising:
the method comprises the steps of enabling a transformer to be equivalent to a two-port network, injecting a first excitation signal into one end of the transformer, and detecting a first response signal which causes oscillation of the two-port network at the other end of the transformer;
transforming the first excitation signal into a second excitation signal and the first response signal into a second response signal by time-frequency transformation;
calculating a winding frequency response in a frequency domain according to the second excitation signal and the second response signal, and drawing a frequency response amplitude spectrum according to the winding frequency response;
performing discrete Fourier transform on the discrete time sequence at the nth moment in the frequency response amplitude spectrum to obtain a frequency spectrum value at the nth moment;
and acquiring the discrete time sequence of the n +1 moment, calculating to obtain the frequency spectrum value of the n +1 moment according to the frequency spectrum value of the n moment and the discrete time sequence of the n +1 moment, and judging the state of the transformer winding according to the frequency spectrum value.
2. The transformer winding condition monitoring method of claim 1, wherein transforming the first excitation signal into a second excitation signal and the first response signal into a second response signal by time-frequency transformation comprises:
Figure QLYQS_1
Figure QLYQS_2
wherein, U i (n) is a first excitation signal, U o (n) is the first response signal, U i (k) Is a second excitation signal, U o (k) Is a second response signal, N is a time series index, N =0,1, \8230;, N-1; k is more than or equal to 0 and less than or equal to N-1; n is the number of sampling points of the signal, k is the index of the frequency spectrum sequence, and j is an imaginary unit.
3. The method of monitoring transformer winding condition according to claim 2, wherein said calculating a winding frequency response in a frequency domain from said second excitation signal and said second response signal comprises:
Figure QLYQS_3
where H (f) is the winding frequency response.
4. The method for monitoring the winding state of a transformer according to claim 1, wherein the discrete time sequence at the nth time in the frequency response amplitude spectrum is subjected to discrete fourier transform to obtain a frequency spectrum value at the nth time, and the method comprises the following steps:
Figure QLYQS_4
wherein X n (k) The spectrum value of the k-th frequency point obtained by the discrete Fourier transform at the nth time is shown, M is a time sequence index, and M =0,1, \8230;, M-1; m is the number of sample points of the signal, k is the spectral sequence index, q represents the number of window function slips, q =0,1,2,3, \8230;, and q = n-M +1.
5. The method according to claim 1, wherein the calculating the spectral value at the n +1 th time from the spectral value at the n th time and the discrete time series at the n +1 th time comprises:
and adding the frequency spectrum value at the nth moment and the sampling signal value of the discrete time sequence at the (n + 1) th moment, subtracting the sampling signal values before the M moments, and then carrying out phase shift to obtain the frequency spectrum value at the (n + 1) th moment.
6. A transformer winding condition monitoring device, comprising:
the signal acquisition module is used for enabling a transformer to be equivalent to a two-port network, injecting a first excitation signal into one end of the transformer, and detecting a first response signal causing oscillation of the two-port network at the other end of the transformer;
the signal conversion module is used for converting the first excitation signal into a second excitation signal and converting the first response signal into a second response signal through time-frequency conversion;
the frequency response amplitude spectrum drawing module is used for calculating the winding frequency response in a frequency domain according to the second excitation signal and the second response signal and drawing a frequency response amplitude spectrum according to the winding frequency response;
the discrete Fourier transform module is used for performing discrete Fourier transform on the discrete time sequence at the nth moment in the frequency response amplitude spectrum to obtain a frequency spectrum value at the nth moment;
and the transformer winding state monitoring module is used for acquiring the discrete time sequence at the moment n +1, calculating to obtain the frequency spectrum value at the moment n +1 according to the frequency spectrum value at the moment n and the discrete time sequence at the moment n +1, and judging the transformer winding state according to the frequency spectrum value.
7. The transformer winding condition monitoring device of claim 6, wherein the signal transformation module is further configured to:
Figure QLYQS_5
Figure QLYQS_6
wherein, U i (n) is a first excitation signal, U o (n) is the first response signal,U i (k) Is the second excitation signal, U o (k) Is a second response signal, N is a time series index, N =0,1, \8230;, N-1; k is more than or equal to 0 and less than or equal to N-1; n is the number of sampling points of the signal, k is the index of the frequency spectrum sequence, and j is an imaginary unit.
8. The transformer winding condition monitoring device of claim 7, wherein the frequency response magnitude spectrum plotting module is further configured to:
Figure QLYQS_7
where H (f) is the winding frequency response.
9. The transformer winding condition monitoring device of claim 6, wherein the Fourier transform module is further configured to:
Figure QLYQS_8
wherein, X n (k) The spectrum value of the k-th frequency point obtained by the discrete Fourier transform at the nth time is shown, M is a time sequence index, and M =0,1, \8230;, M-1; m is the number of sampling points of the signal, k is the spectral sequence index, q represents the number of window function slips, q =0,1,2,3, \ 8230;, and q = n-M +1.
10. A computer-readable storage medium, comprising a stored computer program, wherein the computer program, when executed, controls an apparatus in which the computer-readable storage medium is located to perform the transformer winding state monitoring method according to any one of claims 1 to 5.
CN202211144447.7A 2022-09-20 2022-09-20 Transformer winding state monitoring method and device and storage medium Pending CN115856723A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116226766A (en) * 2023-05-08 2023-06-06 南洋电气集团有限公司 High-voltage electrical apparatus running state monitoring system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116226766A (en) * 2023-05-08 2023-06-06 南洋电气集团有限公司 High-voltage electrical apparatus running state monitoring system
CN116226766B (en) * 2023-05-08 2023-08-18 南洋电气集团有限公司 High-voltage electrical apparatus running state monitoring system

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