Testing and Diagnosis of Extra High Voltage Power Cables Using Damped AC Voltages Combined with Distributed Partial Discharge Measurement

Abstract

State assessment method of cables with extruded insulation and their accessories, DAC withstand test combined with a diagnostic test (such as PD measurement) has two shortcomings, the output voltage is not high enough for EHV cables, it cannot detect and locate PD effectively when defects are far away from signal acquisition point. This paper focus on DAC voltages up to 250kV and a kind of distributed measurement of PD. Defects existing in arbitrary of tested cable can be accurately measured in theory by installing sensor at intervals along the tested cable. This method has been validated on a long extra high voltage cross-linked polyethylene (XLPE) insulated underground cable circuit and the filed PD test has been completed successfully.