A NOVEL LOCALIZATION METHODOLOGY FOR PARTIAL DISCHARGE IN POWER TRANSFORMER CONSIDERING INTERNAL STRUCTURE

Ultrasonic method has been widely studied in the field of partial discharge location of power transformer. Previous studies mainly focused on solving the time difference of arrival (TDOA) equations by using different optimization algorithms. However, the complex structure in the transformer will have a great influence on the propagation path and arrival time of ultrasonic signal, and then affect the positioning accuracy. In this paper, the influence of the internal structure of transformer on the ultrasonic propagation paths is explained in detailed. Based on the theoretical analysis, a numerical node model of transformer is established. Based on the model, A* routing algorithm considering the influence of internal structure is proposed to calculate the fastest propagation path between nodes. In order to verify the accuracy of the positioning algorithm, the positioning experiment is carried out on a 35kV transformer.