Enhanced Partial Discharge Evaluation Through Integrated RF and IEC Measurements

In light of growing regulatory concerns regarding the environmental impact of SF6, it is crucial to develop diagnostic procedures that can identify defects in systems utilising alternative gases for insulation. This study examines the application of carbon dioxide and technical air (N2/O2, 79%/21%) in high-voltage applications. Partial discharge assessment is a well-established technique for condition monitoring, commonly employing conventional (IEC 60270) and radio frequency techniques. Simultaneously measuring partial discharge using both radio frequency and electrical detection methods might yield valuable insights into the shape of the fundamental current pulse, which would otherwise be unattainable by merely relying on one methodology. This paper describes the integration of radio frequency and conventional measurements to evaluate the partial discharge properties of technical air and carbon dioxide gas insulating medium. Distinctive patterns become evident when plotting the energy of the radiated pulse versus apparent charge for a particular defect source. These patterns may appear as either curved or clustered data. The integration of the two measurements offers the opportunity to leverage the respective advantages of each approach while mitigating certain limitations that arise when relying solely on one method of measurement.