PD diagnosis on medium voltage cables with oscillating voltage

Even in times of deregulation, the underground cable networks of the power supplier is one of the most important assets. This fact is often not considered the way it should be in the planning of investment budgets, i.e., the presently practised incident-oriented maintenance leads step-by-step to the exhaustion of the still available safety reserves. Since the beginning of the eighties, a large number of XLPE first generation cables have shown the known “water treeing“ and have meanwhile been exchanged or renovated for the most part. It is possible to determine the condition of these cables with the known dielectric diagnosis methods [1–6], which will certainly be necessary for the next 10 years as well.