Evaluation of partial discharge in inverter driven medium voltage propulsion coils

Evaluations of partial discharge (PD) in 4160 V propulsion coils have been conducted to understand the impact of inverter drives on electric motors as the US Navy moves toward the "electric" ship. The influence of voltage level, voltage rise-time, switching frequency and temperature on the generation of PD for two different coil insulation systems was determined by optical and electrical PD detection methods. This paper describes the process of characterizing PD conditions comprehensively based on the above four parameters, for a drive system consisting of an inverter and a high torque, low speed motor. The test setup is described as well as comprehensive results and analyses.