Study of corona with and without barrier at 0.1 Hz and 50 Hz frequency sinusoidal voltage excitation

Abstract

Partial Discharge (PD) measurement is a very important tool for insulation diagnosis of High Voltage (HV) equipment. The interpretation of PD data is very challenging and has ability to diagnose incipient faults in HV equipment. PD measurement at normal operating power frequency (50/60 Hz) is being carried out for decades and the data interpretation is widely established. At present there is a need of PD measurement to be performed at different frequency of excitation voltage such as Very Low Frequency (0.01–0.1) Hz. But the data interpretation and diagnosis becomes challenging because of limited available studies. In this paper, an attempt is made to compare the corona characteristics, with and without insulation barrier, at Very Low Frequency (0.1Hz) and normal operating power frequency (50 Hz). The corona characteristics used for comparison include average charge magnitude, inception voltage and Phase Resolved Partial Discharge (PRPD) pattern.