Partial Discharge Characteristics of Nanocomposite Enameled Wire for Inverter-Fed Motor

Recently, partial discharge (PD)-resistant enameled wires mixed with inorganic particles of nanometer order, referred to as the nanocomposite enameled wires, have been developed and verified to have longer life compared with conventional enameled wires. We investigated the fundamental characteristics on PD inception, propagation and breakdown (BD) of nanocomposite enameled wire under surge voltage conditions. Electrical and optical PD measurements were carried out for twisted pair samples with nanocomposite and conventional enameled wires. Experimental results revealed that there was no difference in PD inception voltage (PDIV) between both wires. The relationship between applied voltage and time to BD (V-t characteristics) exhibited the longer life of nanocomposite enameled wires, e.g. 2-20 times of conventional enameled wires, which was highly influenced by the applied voltage level and the repetition rate.