Analysis of partial discharge activity at different temperatures through an heuristic algorithm

Partial discharge, PD, activity is strongly influenced by the temperature. The analysis of PD phenomenon in a void embedded in an insulating material is a difficult problem because such voids are physically inaccessible. On the basis of a numerical model for the simulation of PD activity, it is possible to give a good interpretation of the physical parameters values. The developed model is stochastic and it depends on these parameters, which need to be optimised as the temperature changes. On this purpose, an Evolutionary Algorithm has been used for the parameters optimisation. This algorithm is a Differential Evolution strategy for non-linear optimisation with mixed continuous and discrete variables. For this application, it has proved to be more efficient as compared to other enhanced evolutionary algorithms. In the search algorithm, the objective function has been calculated by means of the Weibull distribution, which is used to extract valuable information from a set of stochastic data. In this way, it is possible to compare the cumulative probability distribution of the experimental data and of the calculated data