부산대학교 도서관

Acoustic detection is one of the main methods to detect partial discharge (PD) in the power transformer. The arrangement of ultrasonic sensors is the key factor affecting the accuracy of partial discharge detection. Therefore, it is necessary to understand the ultrasonic propagation characteristics of the transformer. In this paper, the 3-D simulation model of the 220 kV transformer was established. The propagation of the PD ultrasonic signal and the acoustic pressure distribution on the surface of the transformer were studied by using the finite element method. The simulation results show that when the partial discharge occurs, the ultrasonic signal spreads rapidly in the form of a spherical wave. Then the ultrasonic wave will deform and attenuate due to the influence of propagation distance and sound velocity. Besides, the pressure distribution on the surface of the tank caused by PD ultrasound shows that the PD source is the center of the ultrasound outward diffusion. The simulation and analysis results in this paper can provide a basis for determining the layout scheme of the transformer PD ultrasonic sensors.