抄録
The development of feeding cables is being advanced for use in supplying power to propulsion coils with a view of realizing the Yamanashi experimental lines of superconducting magnetic levitation railway (Maglev). To the XLPE insulation of feeding cables, a step voltage waveform is applied by an inverter in which high frequencies are superimposed on the basic commercial frequency. The authors deviced electrical testing equipment that can output such specific waveforms, and they investigated the effect of such waveforms on the insulation properties of XLPE cable, the breakdown characteristics of the model cables and their long-term characteristics. As a result, it was learned that the insulation breakdown depends on the voltage waveform peak value, and that the long- term characteristics are determined by the basic frequency. This knowledge will be usuful for the insulation design of feeding cable system of Yamanashi experimantal line.
