A Transformer Winding Working State Detection Method Based on Weighted Gradient Structural Similarity

Abstract

The invention relates to a transformer winding working state detection method based on weighted gradient structure similarity. The method comprises the steps: (1), carrying out a sweep frequency excitation test on a transformer winding to obtain a vibration frequency response curve of the transformer winding; (2), expressing the vibration frequency response curve of the transformer winding as a matrix X; (3), dividing the matrix X into M*M matrix blocks; (4), calculating a weighted gradient structure similarity value of the matrix X and a matrix Y expressed by a historical transformer winding vibration frequency response curve; and (5), determining a winding state according to the weighted gradient structure similarity value of the vibration frequency response curve of the transformer winding. According to the invention, a winding state of a transformer can be diagnosed and the changing situation of the transformer winding can be detected efficiently and sensitively. Meanwhile, the vibration frequency response curves of different measurement points are considered comprehensively and the weighted gradient concept is introduced, so that the influence on the determination result by the measurement error can be minimized.

Description

technical field [0001] The invention relates to a signal monitoring method, in particular to a detection method for the working state of a transformer winding. Background technique [0002] Large-scale power transformers are the most important primary electrical equipment in the power grid, and their performance directly affects the safe and stable operation of the power system. For long-term power transformers, their reliability is very important. As the capacity of my country's power grid continues to increase, the short-circuit capacity increases accordingly. The huge electromagnetic force generated by the surge current formed by the short-circuit at the transformer outlet will pose a serious threat to the mechanical strength and dynamic stability of the transformer winding. If the faulty transformer is not repaired in time, it will not only damage the transformer, but also affect the normal operation of the power grid, and even cause the power system to collapse. [000...

AI Technical Summary

Problems solved by technology

[0004] Transformer winding deformation detection is one of the routine test items of transformers at present. There are two most commonly used detection methods: one is the short-circuit impedance method, which measures and analyzes the short-circuit impedance or leakage reactance of transformer windings under power frequency voltage. Or the change of leakage reactance to judge whether the transformer winding has changed that affects the safe operation, but this method has low sensitivity and low fault detection rate, and can only get more accurate diagnosis results when the overall deformation of the transformer coil is serious

The second is the frequency response analysis method. By measuring the transfer function of the transformer winding and describing it from the frequency domain, it is possible to diagnose whether the transformer winding has changed. A lot of experience, it is difficult to form a clear quantitative criterion

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