Simulation Study of Partial Discharge UHF Wave Transmission Characteristic in GIS Typical Structure

Defects inside the gas-insulated switchgear (GIS) will produce ultra-high frequency (UHF) electromagnetic waves. The waves will be affected by the shell of GIS when propagating inside the GIS cavity. In the 0-3GHz frequency range, propagation characteristic of electromagnetic which is excited by partial discharge in GIS is simulated based on the method of finite difference time domain (FDTD). This paper designs the GIS simulation models with and without insulator according to the size of a 220kV single phase GIS bus and sets a metal protrusion defect on the bus as the PD source. The transmission characteristics of model waves inside typical GIS structures, and the influence of the insulator to the propagation of electromagnetic wave was studied via setting the different directions of electromagnetic, comparing the time and frequency domain results of electromagnetic wave in different structures and measurement angles.