Development of a Detection Device For Deteriorated ZnO Surge Arresters at AC Traction Substations

Abstract

This paper presents a novel detection device for deteriorated zinc-oxide (ZnO) surge arresters. It is necessary to understand the state of ZnO surge arresters for AC traction substations under operation. The waveform distortion of leakage currents can be detected through an increase in multiple harmonic currents; therefore, this effect was employed to develop a device for diagnosing damage to the surge arrester. By adopting a Rogowski coil and band-pass filters, we can obtain more output of the 5th-15th order harmonic currents in comparison with conventional devices. If the threshold value of harmonic elements is exceeded, the lights on the device may light up to indicate the deterioration. The validity of the device was verified by artificial deterioration tests using damaged ZnO elements and a capacitor. This developed device could indicate the soundness of the surge arresters that are in proper working order while being under the influence of feeding voltages, which include harmonic voltages.