抄録
To improve GIS insulation specifications, it is important to recognize the insulation characteristics under oscillatoryovervoltage waveforms occurring in the field. This paper describes investigations of insulation characteristics for single-frequency oscillatory waveforms with various frequencies and damping ratios. As a result, it was obtained that minimum breakdown voltages (Vmin) rose with frequency rising under same damping condition and Vmin rose with damping ratio rising under same frequency condition. From an analysis of actual breakdown voltage characteristics, a probability of breakdown at a valley of oscillation rose with damping increasing. It was found that the insulation characteristics were treated all-inclusively based on the characteristics of Vmin for rising time or damping time.
