Prediction of Partial Discharge Pulse Height Distribution Parameters using Linear Prediction Method

Partial Discharges (PD) studies have been traditionally used to monitor tree growth in electrical insulation. In this work polymethyl methacrylate (PMMA) samples with a needle plane gap have been aged with AC voltage. The tree growth is monitored simultaneously with collection of PD at regular intervals of time and taking microphotographs in real time without interrupting the aging voltage. The partial discharge pulse amplitude records are clustered together into groups of class intervals. The sequence of PD pulse height records are quantified as time series of eta (shape) and sigma (scale) of Weibull distribution. An auto regressive (AR) model has been devised in MATLAB for analyses and prediction of eta and sigma. Linear prediction method has been used to verify the results.