A new computer-aided measuring system for fundamental PD-studies

PD (partial discharge) monitoring in combination with time-resolved measurements is demonstrated to be a suitable tool for insulation diagnosis. Apart from statistical interpretations of phase-resolved PD patterns for fault recognition, description of material degradation and prediction of lifetime expectancy is desired. Time-resolved measurements yield information about physical processes within the insulation and can be used to explain the coherence between measured PD parameters, their statistical analysis, and the inner processes. PD quantities such as inception field strength, maximum apparent charge, and surface charge at the void walls are calculated and compared with experimental results. Numerical simulations of PD patterns for a void within polyethylene based upon these calculations are in good accordance with measured ones