Failure diagnostic method for dynamic stable state of power transformers

Abstract

The invention relates to a failure diagnostic method for the dynamic stable state of power transformers. In the failure diagnostic method, the deformation condition of power transformer windings is analyzed by combining a frequency response process and an impedance process, the power transformers which have the same types and different serial numbers, the same windings with different phases and indexes of the correlation degree of frequency curves of the dynamic stable state are obtained by the frequency response process. The failure diagnostic method comprises the following steps of: analyzing the dynamic stable state of the power transformers according to related coefficients by synthesizing the advantages of the synthesize technology and the impedance process; when exceeding a permissible value, judging the related coefficients by the impedance process; and when numerical values of parameters also exceed the permissible value, determining that the failure of the dynamic stable state of the power transformers occurs.

Description

technical field [0001] The invention relates to the detection technology of a power transformer, in particular to a method for diagnosing a fault in a dynamic and stable state of a power transformer. Background technique [0002] As an important main equipment in the power system, the safe operation of the transformer will seriously affect the safe operation of the power grid. With the rapid development and construction of the power grid, more and more transformers are in operation, and many large transformer accidents are caused by the short circuit of the low voltage side of the transformer. The anti-short circuit capability of transformers has become an important index to measure transformers, and it is a necessary condition to ensure the safe operation of medium and low voltage systems in power grids. At present, the transformers operating in the Yunnan power grid have been in operation for decades. These transformers have poor short-circuit resistance and are prone to ...

AI Technical Summary

Problems solved by technology

However, this method needs to be compared with the original frequency response characteristic curve to judge the deformation degree of the transformer winding. In the absence of the original frequency response characteristic curve, misjudgment or misjudgment may also occur. The impedance method is more sensitive to the deformation affecting the overall inductance. Such as radial deformation, axial twist, open circuit and short circuit between turns, etc., but not sensitive to local tension and compression between turns, overall displacement of coil, tap changer contact ablation, etc.