Partial discharges evaluation method at HVDC conditions

Summary

There is no standardised method for detection of partial discharges in HVDC systems supplied with DC voltage. Because high voltage diagnostics must follow the actual state of the industry devices and the problems related to diagnostics methods, one of the diagnostic methods necessary to be solved at this time is the partial discharge detection, diagnostics and analyses in HVDC systems. The present study shows the application of pulse sequence analysis to analyse the partial discharges at DC voltage. The experiment with typical corona arrangement - needle-plane at DC voltage was prepared. The measured data at DC voltage are compared to data measured at the same arrangements at AC voltage. The pulse sequence analysis has been applied for both AC and DC voltage and the data are plotted and compared. The aim of the study is to present the connection of pulse sequence data of apparent charge and pulse time differences between AC and DC. Due to the difficulties at partial discharge measuring according to the standards the pulse- sequence- analysis was applied. It is shown that the different evaluation possibilities by using this method could give additional information about the physical processes during the discharge activities. Especially the time dependence of the measured values is a crucial parameter for DC conditions and must be further investigated.

Additional informations

Authors

YASHODHARA, NIRGUDE, SANDHYA, SARMA

Keywords

partial discharge, pulse sequence