Pulse sequence analysis (PSA) on PD data from electrical trees grown in various materials

Phase resolved partial discharge (PD) data have been recorded from electrical trees grown in a flexible epoxy resin, a silicone gel and a silicone rubber with and without a nanofiller. The epoxy resin samples and silicone gel samples did not contain any filler particles. In the case of silicone rubber, organo-Montmorillonite (oMMT) nanofiller, was used. The electrical treeing experiments were carried out at different temperatures in the range 20-60°C. The details of PD dynamics during the electrical tree growth have been found to change significantly with temperature in some of the polymer systems investigated. An attempt is made to identify features which are present in the PD patterns irrespective of the host polymer matrix using PSA plots and unique to the partial discharge process in electrical trees. Such features can be used for reliable diagnostics and condition monitoring of real-life electrical insulation systems.