Examination of Electromagnetic Mode Propagation Characteristics in Straight and L-Section GIS Model Using FD-TD Analysis

• Published in: IEEE transactions on dielectrics and electrical insulation Vol. 14; no. 6; pp. 1477 - 1483
• Main Authors: Hikita, M., Ohtsuka, S., Teshima, T., Okabe, S., Kaneko, S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accident prevention; Dispersions; Electromagnetic analysis; Electromagnetic modeling; Electromagnetic propagation; Finite difference time domain method; Gas insulation; Insertion; Insulation; Mathematical models; Partial discharge measurement; Partial discharges; Propagation; Reflection; Switchgear; UHF
• ISSN: 1070-9878; 1558-4135
• DOI: 10.1109/TDEI.2007.4401231

It is an effective method of insulation accident prevention for gas-insulated switchgear (GIS) to detect a partial discharge (PD) that occurs as a preceding phenomenon for an insulation accident. Among various methods, a PD detection method based on the detection of electromagnetic emission through measurement of the UHF band (300 MHz to 3 GHz), which is relatively free of influences from external noises, is drawing attention as an effective method in terms of extensive and highly sensitive detection. This paper describes conducting EM-wave propagation analysis on GISs with L-sections using the finite difference-time domain (FD-TD) method and examining the influences of the Insertions on the propagation characteristics of EM-wave modes with comparison of straight GIS part. As a result, this study identified that, even on a straight GIS, the velocity dispersion characteristic of high-order modes resulted in a decrease in the crest value even if there is no reflection or conductor loss in the discontinuities. And that mode conversions and reflections in L-sections also resulted in a decrease in the crest value.