Identification and detection of slot discharges during accelerated aging tests

Partial-discharge amplitude distribution (PDAD) analysis can be usefully applied in the detection and identification of slot discharge activity during accelerated aging tests. A sequential thermal, mechanical, and electric stress was applied to 10 U-shape frames simulating complete stator slots, in order to reproduce slot discharges in a relatively short time. From a Weibull plot of the detected cumulative distributions, the slot discharges can be identified by their distinctive pattern even though the inception of the phenomena may be mixed up with other discharge patterns. These results confirm the validity of the PDAD shape analysis approach as a possible tool for classifying the detected phenomena both in the laboratory and during partial discharge measurements in HV generator stator windings