Simulation Study on Electromagnetic Wave Propagation Characteristics Within L-Type and T-Type Gas-Insulated Switchgear Model
Yanming Li · Power System Technology · 2008
By use of finite difference time domain (FDTD) method, the simulation of propagation characteristics of electromagnetic wave (E-M wave) within L-type and T-type gas-insulated switchgear (GIS) model is performed. The distribution and its impact of E-M waves within the GIS with L-type and T-type structure on their own propagation characteristics are analyzed. Study results show that affected by speed dispersion characteristic, at the straight portion of GIS cavity the peak-to-peak value of the received E-M wave signal distributes by attenuation law along with the receiving point away from the excitation source, however, the total energy changes little. For GIS with L-type and T-type structure, after the signal passing through these structures the signal energy attenuates remarkably. Results of the signal frequency analysis show that in the direction of 0° there are transverse electromagnetic (TEM) wave and high order model waves such as TE11, TE21 and TE31 and so on, yet in the direction of 90° there are only TEM wave and TE21 model wave. The differences of signal frequency components lead to the discrepancy of signal energy distribution in different receiving directions.