On-site application of dielectric response diagnosis on service aged oil-impregnated HV power cables

Knowledge rules for paper/oil insulated high voltage (HV) power cables are necessary to support asset management decision processes. For development of these knowledge rules investigation has been done into a diagnostic method, for integral condition assessment of paper/oil insulation to DC voltage charging. This method is called the recovery voltage measurement and is based on the dielectric response of cable insulation. In the recovery voltage (RV), parameters have been investigated on possibility to indicate insulation degradation. In this paper single and periodic measurements with different temperatures have been performed. These measurements result in the conclusion that an increase in insulation degradation can be observed by selected recovery voltage parameters as well as dielectric losses behavior in function of test voltage. Measurement results of HV power cables performed at two temperatures can be used in line with dielectric losses measurements to support condition assessment.