Considerations on the insulation degradation characteristics by functional tests

Abstract

This paper describes the results of various insulation degradation characteristics measured in functional tests using form-wound motorettes and discusses on the effective insulation diagnostics. The measured insulation degradation characteristics are insulation resistance, dissipation factor, discharge intensity, discharge phase, partial discharge characteristics, y, etc. and breakdown voltage. Different types of functional test were carried out to evaluate the thermal life and voltage endurace life of the insulation system. The paper concludes that the insulation degradation characteristics make a drastic change with the type of degradation stress and a new location method to detect the local degradation will be needed to develop.