Partial Discharge Detection with High-Frequency Band through Resistance-Temperature Sensor of Hydro Power Generator Stator Windings

Abstract

In order to improve S/N ratio for partial discharge (PD) detection using a resistance-temperature detector laid in stator windings of hydro-power generator, continuous wavelet transform (CWT) is applied as a kind of time-frequency analysis. Relying on the combination of frequency resolution and time resolution using an applied power voltage phase angle distribution, PDs occurring in voids of stator windings are thought to be found within mixed environment of large noises and confusable noises. Furthermore, we found that CWT may make it possible to calibrate PD charge quantity in a few tens of MHz band under favorable conditions where the calibration is usually difficult for generator stator windings.