Method for detecting deformation of power transformer windings

Abstract

The invention discloses a method for detecting deformation of power transformer windings. The method includes the following steps that the short-circuit impedance relative change rate, the overall correlation coefficients of amplitude-frequency curves, the amplitude-frequency curves of a low frequency band, a medium frequency band and a high frequency band, the local correlation coefficients of the amplitude-frequency curves of all the frequency bands, the voltage ratio deviation and the capacitance relative change rate are acquired; the deformed windings and phase results are acquired according to the short-circuit impedance relative change rate and the overall correlation coefficients of the amplitude-frequency curves; according to the correlation coefficient of the amplitude-frequency curve of the low frequency band and the voltage ratio deviation, turn-to-turn or cake-to-cake short circuit detection results are acquired; according to the correlation coefficient of the amplitude-frequency curve of the medium frequency band and the capacitive relative change rates between the windings, local deformation results are acquired; according to the correlation coefficient of the amplitude-frequency curve of the high frequency band and the ground capacitance relative change rates of the windings, whole displacement or lead displacement deformation detection results of winding coils are acquired; the results are logically processed, and a comprehensive detection result is acquired. According to the method, reliability of the deformation detection result of the power transformer windings is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of transformers, and more specifically relates to an analysis method for winding deformation of power transformers. Background technique [0002] With the increasing installed capacity of the power system, the short-circuit capacity and short-circuit current in the system also increase, and various short-circuit accidents near the outlet of the power transformer running in the system will inevitably occur. When a power transformer is subjected to a short-circuit impact, the strong power generated by the short-circuit current in the winding will damage the winding insulation and mechanical properties to varying degrees, and in severe cases, the transformer can be damaged. A short circuit at the outlet of the transformer at a close distance will cause winding deformation, insulation damage, and winding burnout. A short-circuit accident will generally cause the transformer to trip and withdraw from operation, ...

AI Technical Summary

Problems solved by technology

[0008] In view of the above defects or improvement needs of the prior art, the present invention provides a detection method for the deformation of the power transformer winding, which solves the problem of low accuracy of the existing detection method and improves the accuracy of the analysis and diagnosis of the deformation of the transformer winding

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