도시철도 쵸파형 전동차 배리스터(varistor) 유지보수 방안 연구

A Study on the Varistor Maintenance program in urban rail chopper type subway train

In the case of an urban rail chopper type subway train, varistors have been installed for protecting usual electronic equipments, semiconductor devices(diodes, transistors, thyrister, etc.) communications, measuring, control device and absorbing opening & closing surge of electromagnetic valve. These varistors were steadily reduced dielectric strength as becoming superannuated. Thus there is a problem that reacts more sensitive at the same surge in the general control operation. On existing maintenance, there is not specific standard to replace superannuated varistor. So when maintaining chopper type subway train, all varistors or old varistors that workers checked a discoloration & crack with the naked eye and noticed degradation smell by deterioration are replaced. This study suggests detail standards for judgement that varistors are good or bad chopper type subway train, and it draw a efficient maintenance which efficient maintenance can check more easy the degradation properties variation.