Experimental Investigation on Detection and Localization of AC Partial Discharge in Form Wound Stator Windings in Rotating Machines Using HFCT Sensors

This study aims to enhance insulation diagnosis technology for rotating electrical machines through partial discharge (PD) measurement. Specifically, we aim to develop a high-frequency (HF) equivalent circuit simulation technique to estimate the PD current propagation path within form-wound stator windings. To gain insights toward this objective, we investigated the propagation characteristics of PD currents generated at artificially introduced defects in form-wound stator windings. As a result, PD current signals obtained from the HFCT (High Frequency Current Transformer) in the developed experimental setup exhibited strong frequency components around 5 MHz, which were successfully reproduced in the simulation. However, certain aspects of the PD current waveform shape could not be fully replicated in the analysis. This discrepancy is presumed to be due to the influence of the applied voltage conditions in the simulation. Therefore, future work will focus on reviewing and refining the simulation conditions.