Laboratory and Field Partial-Discharge Studies by a Utility

This paper describes partial discharge tests and evaluations made by Philadelphia Electric Company on solid dielectric extruded cables which were giving unsatisfactory service. Both theoretical calculations and actual measurements are presented and are related to the analyses of the causes of poor cable performance. The practical application of partial discharge measurements in a utility for evaluating cable condition is discussed. In addition to laboratory work, the paper also includes data obtained in a successful field test of a short section of cable in a substation yard. Partial discharge measurements are shown as an informative non-destructive quality test.