Response of PD Couplers to External Discharges

Abstract

When partial discharge measurements are made on individual stator coils or bars an objective may be the detection of internal voids and delaminations. In this case a detection system that is relatively insensitive to external discharges may be appropriate. As an example, the response of three different coupling systems is provided for coils and bars having external discharges associated with the stress control zone adjacent to the slot.