A Joint Simulation of UHF Signal Generation and Propagation Based on Pulsed Current Model of Partial Discharge

This article is devoted to simulating the generation and propagation of EM waves caused by the partial discharge (PD) inside a void defect. Although many researchers have focused on the micro discharge process, few researchers are studying its impact on ultrahigh-frequency (UHF) signal generation. For simplicity, several studies replace PD with a predetermined Gaussian source. This article proposes an accurate pulsed current model for UHF signal generation which further links the waveform of the source with the discharge condition. At the micro level, the PD is caused by the penetration of void defects, whose steep rising edge further generates electromagnetic waves. Based on that, this article simulates the PD UHF signal by combining the micro discharge process and the macro transmission process. For the micro discharge process, a positive streamer caused by dielectric barrier discharge (DBD) is studied, and the discharge current can be obtained. For the macro transmission process, the finite-difference time-domain (FDTD) method is used to calculate the propagation of UHF signals. The proposed method builds a more direct relationship between observed UHF signals with the discharge process; thus it is helpful to establish an inverse model from UHF values obtained by sensors outside to the insulation defect inside of the equipment.