The Application of FDTD Method to UHF Electromagnetic Wave Analysis in Gas Insulated Switchgear

摘要

Gas Insulated Switchgear is an important equipment in a substation, and it's highly desirable to analyze a partial discharge occurring in GIS which is a symptom of an insulation breakdown. Ultra high frequency (UHF) electromagnetic wave can be radiated by partial discharge. In order to explore the relationship between UHF signal and partial discharge sources in GIS, this paper proposes a method of finite difference time domain (FDTD) to investigate the characteristics of UHF signal. With the resort to the XFDTD simulation of electromagnetic wave propagation in GIS, factors such as PD current pulse amplitude and pulse width are analyzed. The result shows that UHF signals have direct relation to the distance of PD source. And when the pulse width is constant, the square root of UHF signal energy is direct ratio to the amplitude of the real pulse.