Partial discharge testing and AC characterization of HV connectors and terminations

Characterization of partial discharge behavior is an effective tool in selecting dielectric materials, establishing voltage ratings, and indentifying exposure dependent failure modes of high voltage connectors and terminations. By understanding a component´s response to partial discharge activity, material selection, geometries, and interfaces can be optimized to increase endurance and reliability. Partial discharge behavior is associated with dielectric aging and exposure dependent reduction in dielectric strength. Long term electrical aging influences several stress types, which have reversible and/or irreversible effects on the material and result in electrical, thermal, and partial discharge breakdown mechanisms. When combined with partial discharge measurements, a life-stress relationship is established using accelerated life testing, with thermal, voltage, and time acceleration factors. Since long-term electrical ageing exists with the presence of partial discharge, inception and extinction voltages are used to establish criteria for accelerated life test voltages. A methodology is presented for performance of partial discharge detection, selection of life test parameters, and analyses of post test results.