Finite Element Analysis of Ultrasonic Propagation Characteristics of Two-point Partial discharge in Oil-immersed Transformer

In order to analyze the propagation characteristics of the ultrasonic signals generated by the two-point partial discharge inside the oil-immersed transformer, the Finite Element Method is used for modeling and simulation. The temporal, spatial and frequency characteristics of the ultrasonic signals at the partial discharge point inside the transformer are obtained. Compared with the single-point local discharge case, the overall sound pressure amplitude at the place where the sound pressure overlap occurs is approximately doubled in the two-point local discharge case. The frequency distribution ranges at the observation points are also expanded from 10-30kHz at single partial discharge to 10-40 kHz at two-point partial discharge. These provide data support for the detection and positioning of internal partial discharge of oil-immersed transformer.