Research on Evaluation Method of Transient Overvoltage Hazard Based on S-Transform

Abstract

In field operation, the transformer with good insulation design and insulation condition may failure caused by transient over-voltage. The accumulation of transient overvoltage reduces the reliability of transformer internal insulation without signs. Therefore, it is necessary to assess the over-voltage hazards on the transformer. In order to evaluate the transient damage of transformers in operation, the transient overvoltage evaluation method based on S transform is proposed in this paper. Firstly, a method based on traditional Fourier transform is introduced. Secondly, the defects of traditional Fourier transform are analyzed. Finally, a transient overvoltage evaluation based on S transform is proposed to overcome the shortcomings of traditional Fourier transform method.