Voltage dependence of corona signature from defect stator bar insulation during aging

Abstract

Many experiments have been aimed at finding a relationship between partial discharge spectra (1),(2) and insulation condition, but a clear consensus has not yet been formed. The work described is part of a larger effort designed to learn more about the relationships between the life of machine insulation and diagnostic indices derived from corona spectroscopy and other measurements. In particular, it is shown that variations in the voltage used during testing can be a useful parameter in extending the usefulness of both pulse height analysis (PHA) and pulse phase angle analysis (PØA).