A Novel Diagnostic Technique to Study the Ageing of Rotating Machine Insulation: The

Abstract

Rotating machine insulation ageing has been the subject of intensive research over the years. In this paper, model stator bars are investigated with the aid a Partial Discharge (PD) detector. The maximum PD magnitude is recorded as the applied voltage increases and as it decreases. The resulting “hysteresis curve” indicates whether the stator bar is in a “good” or “bad” condition, i.e. it indicates its “state of health”. The proposed method has certain advantages over other methods since it requires only one parameter, i.e. the maximum PD magnitude. It is suggested that the proposed method can be used as a diagnostic tool for assessing the quality and controlling the state of ageing of model stator bars.