Online monitoring method and device for transformer winding deformation

Abstract

The invention relates to online monitoring method and device for transformer winding deformation and relates to the field of power equipment monitoring. The method includes: applying high-frequency sinusoidal signals to a transformer winding, detecting the high-frequency sinusoidal signals on a sleeve end screen and a neutral-point ground wire of the winding, judging whether the transformer winding deforms or not according to current offset, judging the deformation type of the transformer winding according to current offset coefficient, and judging the deformation position of the transformer winding according to a fingerprint of the current offset coefficient. The method and device can be used to monitor health of transformer windings online in real time for a long term so as to precaution early winding deformations and diagnose deformation degree, type and position for the windings, and accordingly winding deformation accidents caused by accumulation of early microdeformations of the transformer windings are reduced effectively.

Description

technical field [0001] The present invention relates to a method and device in the field of electric equipment monitoring, in particular to a transformer winding that monitors the state of the winding by using the high-frequency current offset and current deviation coefficient between the end screen of the transformer winding bushing and the neutral point grounding line. On-line deformation monitoring method and device. Background technique [0002] During long-distance transportation and installation of power transformers, the windings may be subjected to mechanical forces such as collisions or vibrations, as well as various electrodynamic forces during operation, resulting in axial or radial deformations such as local twisting, bulging or displacement of the windings. . Slight deformation of the winding will bring hidden dangers to the safe operation of the transformer and reduce the life of the transformer; major deformation of the winding will cause the transformer to q...

AI Technical Summary

Problems solved by technology

Although the above-mentioned off-line test methods can detect whether the winding is deformed to a certain extent, they all have some defects: the sensitivity of the short-circuit test method needs to be improved, and it is not sensitive to small deformation; the low-voltage pulse method and the frequency response method are affected by the detection environment The influence of external interference is great, and there is a lack of concise and quantifiable judgment basis, which requires high requirements for on-site operators

However, this technology uses winding resistance and leakage inductance as parameter identification, and its identification accuracy directly affects the diagnostic results of this technology, and it is impossible to identify the type and position of winding deformation

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