CN106338237A - Transformer winding deformation detection method based on frequency response impedance method - Google Patents

Abstract

The invention relates to a transformer winding deformation detection method based on a frequency response impedance method. The method comprises the steps that a frequency response method is used to measure voltage and the current signals of the response end and the excitation end of a transformer winding to be detected; measured data are used to calculate the impedance of the winding to be detected at different frequencies; the impedance data of the winding to be detected and the impedance data of the normal winding are used to draw a frequency response impedance curve at low frequency band (10 to 1000Hz) and intermediate frequency band (1 to 45kHz); and acquired impedance data are used to calculate correlation coefficients of two curves, so as to determine the winding deformation. According to the invention, the wiring manner of the frequency response method is used; other criteria are acquired to diagnose the transformer winding deformation; a result and the diagnosis result of the frequency response method are reference for each other; and the correctness of transformer winding deformation diagnosis is improved.

Description

Deformation of transformer winding detection method based on frequency response impedance method

Technical field

The invention belongs to Fault Diagnosis for Electrical Equipment technical field, more particularly, to one kind are based on frequency response impedance method Deformation of transformer winding detection method.

Background technology

Transformator is important electrical equipment in power system, serve as in power system energy distribution, The vital task of electric pressure conversion, its operational reliability is the important guarantor of power system stability safe operation Barrier.Actual motion statistical result shows, winding deformation is one of most commonly seen fault of transformator, reliable, Detect deformation of transformer winding for reduction power transformer accident rate, guarantee transformator exactly Safe operation is significant.

Frequency response method is currently to detect one of topmost method of deformation of transformer winding both at home and abroad.When sharp When encouraging signal frequency higher than 1khz, Transformer Winding can be equivalent to a passive linear network, frequency Response characteristic is a prominent property of this passive linear network.For the transformator of a determination, its Frequency response characteristic is unique, when there is winding deformation due to certain fault in transformator, its winding The frequency response characteristic of equivalent network also can change therewith.When applying frequency response method is tested, Transformer Winding side applies sinusoidal frequency scanning signal, and the opposite side in winding gathers this frequency sweep letter simultaneously Number response signal, then pass through to process to obtain the frequency response curve of winding, before and after relative analyses fault The difference of winding frequency response curve is differentiating the deformation of winding.

In actual test, due to the interference of live electromagnetic signal, and wire length, earth point position With the impact to test result such as the contact resistance of test fixture, cause test data poor repeatability, distortion, Even cause the erroneous judgement to winding deformation.Therefore, using the mode of connection of frequency response method, research is a kind of New transformer winding fault decision method, the diagnostic result reference each other with frequency response method, there is weight The realistic meaning wanted.

Content of the invention

It is an object of the invention to, a kind of deformation of transformer winding detection side based on frequency response impedance method is provided Method, using the mode of connection of frequency response method, obtains other criterions by this method and diagnoses Transformer Winding Deformation, the diagnostic result reference each other with frequency response method, improves the correct of deformation of transformer winding diagnosis Rate.

The technical scheme is that, based on the deformation of transformer winding detection method of frequency response impedance method, have Body comprises the steps of

Step 1: select Transformer Winding to be detected, apply sinusoidal frequency scanning signal u in its one end_s, Measurement response terminal voltage u at different frequencies₂(f), excitation terminal voltage u₁(f) and the electric current flowing through winding i(f).

Step 2: for the voltage, the current signal that gather acquisition in above-mentioned steps 1, by data processing Obtain resistance value z (f) under different frequency.

Step 3: for impedance calculated in step 2, point low-frequency range (10～1000hz) and intermediate frequency Section (1～45khz) draws frequency response impedance curve, and wherein abscissa is frequency f, and vertical coordinate is corresponding resistance Anti- value.In the same manner, by Transformer Winding, frequency response impedance curve when normal is plotted under same coordinate system.

Step 4: for the curve data obtaining in step 3, two curves are defined using correlation coefficient process Similarity, winding deformation situation is judged according to similarity.

In described step 2, specifically comprise the steps of

Step 21: for the voltage recording in step 1, current signal, for frequency in 10～1000hz The data inside recording, according to formula $\stackrel{\→}{z}\left(f\right)=\left(\frac{{\stackrel{\→}{u}}_i\left(f\right)-{\stackrel{\→}{u}}_o\left(f\right)}{\stackrel{\→}{i}\left(f\right)}\right)=r\left(f\right)+\mathrm{jx}\left(f\right)$ With $\left|\stackrel{\→}{z}\left(f\right)\right|=\sqrt{r^2\left(f\right)+x^2\left(f\right)}$ In calculating The resistance value of frequency range.

Step 22: for the voltage recording in step 1, current signal, for frequency in 1～45khz The data inside recording, according to formula $h\left(f\right)=20\log \sqrt{r^2\left(f\right)+x^2\left(f\right)}=20\log \left(\right|\stackrel{\→}{z}\left(f\right)\left|\right)$ Calculate the impedance of Mid Frequency Value.

In described step 4, specifically comprise the steps of

Step 41: for the curve data obtaining in step 2 it is assumed that it is the amplitude that two length are n Sequence x (i), y (i), i=0,1 ... ..., n-1, and x (i), y (i) are real number.Calculate two sequences Standard variance, wherein ${\mathrm{\σ}}_x=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{[x_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{x}_i]}^2,{\mathrm{\σ}}_y=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{[y_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{y}_i]}^2.$

Step 42: for two amplitude sequences in step 41, calculate the covariance of two sequences $c_{\mathrm{xy}}=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}[x_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{x}_i]\×[y_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{y}_i].$

Step 43: for two amplitude sequences in step 41, using the standard variance in step 41 and Covariance in step 42, the covariance of two sequences is done normalized

Step 44: for the covariance lr after normalization in step 43_xyIf, 1-lr_xy＜ 10^-10, then related Coefficient r_xyFor 10；If 1-lr_xy≥10^-10, then correlation coefficient r_xy=-lg (1-lr_xy).

Step 45: for the correlation coefficient r of step 44_xyIf, r_xy＜ 0.6, then judge Transformer Winding as Gross distortion；If 0.6≤r_xy＜ 1, then judge that Transformer Winding deforms as obvious；If r_xy>=1, then winding is being just Often.

Deformation of transformer winding detection method based on frequency response impedance method provided by the present invention, using frequency The mode of connection of response method, obtains other criterions by this method and diagnoses deformation of transformer winding, with frequency The reference each other of the diagnostic result of response method, improves the accuracy of deformation of transformer winding diagnosis.

Brief description

Fig. 1 is the flow process of the deformation of transformer winding detection method based on frequency response impedance method of the present invention Figure；

Fig. 2 is the flow chart calculating resistance value under different frequency described in step 2 of the present invention；

Fig. 3 is the flow chart of the calculating frequency response impedance curve correlation coefficient method described in step 4 of the present invention；

Specific embodiment

Below according to Fig. 1～Fig. 3, illustrate presently preferred embodiments of the present invention.It is emphasized that under State bright being merely exemplary, rather than in order to limit the scope of the present invention and its application.

As shown in figure 1, the deformation of transformer winding detection side based on frequency response impedance method provided by the present invention Method, specifically comprises the steps of.

Step 1: select Transformer Winding to be detected, apply sinusoidal frequency scanning signal u in its one end_s, Measurement response terminal voltage u at different frequencies₂(f), excitation terminal voltage u₁(f) and the electric current flowing through winding i(f).

Step 2: for the voltage, the current signal that gather acquisition in above-mentioned steps 1, by data processing Obtain resistance value z (f) under different frequency.

Step 21: for the voltage recording in step 1, current signal, for frequency in 10～1000hz The data inside recording, according to formula $\stackrel{\→}{z}\left(f\right)=\left(\frac{{\stackrel{\→}{u}}_i\left(f\right)-{\stackrel{\→}{u}}_o\left(f\right)}{\stackrel{\→}{i}\left(f\right)}\right)=r\left(f\right)+\mathrm{jx}\left(f\right)$ With $\left|\stackrel{\→}{z}\left(f\right)\right|=\sqrt{r^2\left(f\right)+x^2\left(f\right)}$ In calculating The resistance value of frequency range.

Step 22: for the voltage recording in step 1, current signal, for frequency in 1～45khz The data inside recording, according to formula $h\left(f\right)=20\log \sqrt{r^2\left(f\right)+x^2\left(f\right)}=20\log \left(\right|\stackrel{\→}{z}\left(f\right)\left|\right)$ Calculate the impedance of Mid Frequency Value.

Step 3: for impedance calculated in step 2, point low-frequency range (10～1000hz) and intermediate frequency Section (1～45khz) draws frequency response impedance curve, and wherein abscissa is frequency f, and vertical coordinate is corresponding resistance Anti- value.In the same manner, by Transformer Winding, frequency response impedance curve when normal is plotted under same coordinate system.

Step 4: for the curve data obtaining in step 3, two curves are defined using correlation coefficient process Similarity, winding deformation situation is judged according to similarity.

Step 41: for the curve data obtaining in step 2 it is assumed that it is the amplitude that two length are n Sequence x (i), y (i), i=0,1 ... ..., n-1, and x (i), y (i) are real number.Calculate two sequences Standard variance, wherein ${\mathrm{\σ}}_x=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{[x_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{x}_i]}^2,{\mathrm{\σ}}_y=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{[y_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{y}_i]}^2.$

Step 42: for two amplitude sequences in step 41, calculate the covariance of two sequences $c_{\mathrm{xy}}=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}[x_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{x}_i]\×[y_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{y}_i].$

Step 43: for two amplitude sequences in step 41, using the standard variance in step 41 and Covariance in step 42, the covariance of two sequences is done normalized

Step 44: for the covariance lr after normalization in step 43_xyIf, 1-lr_xy＜ 10^-10, then related Coefficient r_xyFor 10；If 1-lr_xy≥10^-10, then correlation coefficient r_xy=-lg (1-lr_xy).

Step 45: for the correlation coefficient r of step 44_xyIf, r_xy＜ 0.6, then judge Transformer Winding as Gross distortion；If 0.6≤r_xy＜ 1, then judge that Transformer Winding deforms as obvious；If r_xy>=1, then winding is being just Often.

Although present disclosure has been made to be discussed in detail by above preferred embodiment, but it should understanding It is not considered as limitation of the present invention to the description above.Read above-mentioned in those skilled in the art After content, the multiple modifications and substitutions for the present invention all will be apparent from.Therefore, the present invention Protection domain should be limited to the appended claims.

Claims (3)

1. the deformation of transformer winding detection method based on frequency response impedance method is it is characterised in that described side Method comprises the steps of

Step 1: select Transformer Winding to be detected, apply sinusoidal frequency scanning signal in its one end u_s, measurement response terminal voltage u at different frequencies₂(f), excitation terminal voltage u₁(f) and flow through winding Electric current i (f).

Step 2: for the voltage, the current signal that gather acquisition in above-mentioned steps 1, at data Reason obtains resistance value z (f) under different frequency.

Step 3: for impedance calculated in step 2, point low-frequency range (10～1000hz) and Mid Frequency (1～45khz) draws frequency response impedance curve, and wherein abscissa is frequency f, and vertical coordinate is Corresponding resistance value.In the same manner, by Transformer Winding frequency response impedance curve when normal be plotted in same Under coordinate system.

Step 4: for the curve data obtaining in step 3, two songs are defined using correlation coefficient process The similarity of line, judges winding deformation situation according to similarity.

2. the deformation of transformer winding detection method based on frequency response impedance method as claimed in claim 1, It is characterized in that, in described step 2, specifically comprise the steps of

Step 21: for the voltage recording in step 1, current signal, for frequency in 10～1000hz The data inside recording, according to formula $\stackrel{\→}{z}\left(f\right)=\left(\frac{{\stackrel{\→}{u}}_i\left(f\right)-{\stackrel{\→}{u}}_o\left(f\right)}{\stackrel{\→}{i}\left(f\right)}\right)=r\left(f\right)+\mathrm{jx}\left(f\right)$ With $\left|\stackrel{\→}{z}\left(f\right)\right|=\sqrt{r^2\left(f\right)+x^2\left(f\right)}$ Meter Calculate the resistance value of Mid Frequency.

Step 22: for the voltage recording in step 1, current signal, for frequency in 1～45khz The data inside recording, according to formulaCalculate the resistance of Mid Frequency Anti- value.

3. the deformation of transformer winding detection method based on frequency response impedance method as claimed in claim 1, It is characterized in that, in described step 4, specifically comprise the steps of

Step 41: for the curve data obtaining in step 2 it is assumed that it is two length is n's Amplitude sequence x (i), y (i), i=0,1 ... ..., n-1, and x (i), y (i) are real number.Calculate two The standard variance of sequence, wherein ${\mathrm{\σ}}_x=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}[x_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{x}_i{]}^2,$ ${\mathrm{\σ}}_y=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}[y_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{y}_i{]}^2.$

Step 42: for two amplitude sequences in step 41, calculate the covariance of two sequences $c_{\mathrm{xy}}=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}[x_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{x}_i]\×[y_i-\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\σ}}}{y}_i].$

Step 43: for two amplitude sequences in step 41, using the standard side in step 41 Covariance in difference and step 42, the covariance of two sequences is done normalized ${\mathrm{lr}}_{\mathrm{xy}}=c_{\mathrm{xy}}/\sqrt{{\mathrm{\σ}}_x{\mathrm{\σ}}_y}.$

Step 44: for the covariance lr after normalization in step 43_xyIf, 1-lr_xy＜ 10^-10, then Correlation coefficient r_xyFor 10；If 1-lr_xy≥10^-10, then correlation coefficient r_xy=-1g (1-lr_xy).

Step 45: for the correlation coefficient r of step 44_xyIf, r_xy＜ 0.6, then judge Transformer Winding For gross distortion；If 0.6≤r_xy＜ 1, then judge that Transformer Winding deforms as obvious；If r_xy>=1, then Winding is normal.