Partial Discharge Source Identification in Stator Winding based on Phase-Resolved Partial Discharge Pattern

Abstract

Partial discharges (PD) are tiny electrical sparks that can occur in liquid or solid systems in high voltage equipment, potentially leading to equipment failure. PD activity in the stator winding can be useful for diagnosing insulation in rotating machines. PD severity is determined by its type and location, primarily identified by the Phase Resolved Partial Discharge (PRPD) pattern. In view of the foregoing, this study aims to identify several PD types that commonly occur in stator windings during experimental testing, in accordance with IEC 60034-27-1. A digital PD measurement system was used to quantify and analyze PD. In addition, COMSOL Multiphysics was used to simulate and verify the PD mechanisms as a function of applied voltage. Various PD types have been experimentally investigated, including slot discharge, debonding-type discharge, slot-exit discharge, and microvoid discharge, by creating appropriate defects at multiple locations, such as the slot area, the coil conductor, and the ground wall insulation. As a result, PD source identification in stator windings may provide useful information for assessing the insulation condition of rotating machines, particularly in industry.