Improved Deterministic And Stochastic Models For Simulating Partial Discharges In Non-Conducting Trees Inside Solid Dielectrics

Electrical trees are defects originated and driven by partial discharges (PD) activity and this is the reason why their modelling and simulation are fundamental for the ageing mechanisms comprehension and diagnosis analyses of insulation systems compound by solid dielectrics. This study presents a brief review of the different models implemented to simulate PD in electrical trees inside solid dielectrics. In addition, an improved deterministic model as well as a stochastic model are presented, which allow predicting adequately the PD pulses distribution, in magnitudes and phase, for non-conducting electrical trees of different shape and length. Two case studies were simulated and their results exhibit good agreement when compared with measurements presented in the literature. It is concluded that the main parameters that state the PD behaviour in trees are the inception and extinction voltage magnitudes, including their probability distributions, and the tree geometry. The models can be used for prognosis analysis based on on-line measurements.