Effects of short-time voltage drops and polarity reversals on breakdown behaviour of cross-linked polyethylene

This paper deals with breakdown voltage characteristics of cross-linked polyethylene (XLPE) in homogeneous electric fields. The breakdown behaviour is measured with foils in a sphere-sphere arrangement under the influence of short-time voltage drops. The influence both of fall time and of rise time of DC recovery voltage is discussed in connection with the space charge effect. Moreover, the breakdown voltage was measured in fast polarity reversal experiments. The electrical strength was found to depend mainly on the rise time of DC recovery voltage. Secondly, with respect to service conditions, the influence of temperature on the DC breakdown behaviour was investigated