Simulation Study on UHF Signal Propagation Characteristics of Partial Discharge in the Power Transformer Outlet Device

The arrangement of ultra-high frequency (UHF) sensors will have a great impact on the identification and location accuracy of partial discharge (PD). To realize the PD detection of transformer outlet device by UHF method, it is necessary to study the characteristics of UHF signal of partial discharge at the outlet device. In this paper, a 3D simulation model of the outlet device is established, and the propagation and distribution characteristics of UHF signals of partial discharge at the outlet device are studied by using the FiniteDifference Time-Domain (FDTD) method. The analysis results demonstrate that when PD occurs at outlet device, the UHF signal can only propagate along the oil channel to the end of the porcelain envelope and spread to the outer space. In addition, with the increase of the distance from the end of the porcelain envelope, the amplitude of UHF signal attenuates rapidly. The results can provide a reference for the arrangement of partial discharge sensors in UHF detection of the outlet device.