Physics-based Modeling and Simulation of Partial Discharge for Windings of Inverter Driven Electric Machines
Authors: Han Xiong, Alex Louie, Julia Zhang, Annette von Jouanne
Abstract: Modern variable speed machine drive (VSMD) systems employ high switching frequency power electronics that produce voltage pulses to drive the machine. The electric machine winding terminals are subjected to large voltage overshoot (2 to 4 times the bus voltage), called the reflected wave phenomenon, which is a function of the power electronics switching behavior and power cable impedance. The voltage spikes can exceed the breakdown voltage of winding insulation then a partial discharge (PD) will occur. Successive PD will degrade the winding insulation gradually. Faster switching and longer cables aggravate the voltage overshoot. The use of next generation power electronic devices, such as silicon-carbide and gallium-nitride devices, will impose new challenges to the VSMD insulation system.
This work applies the finite element (FE) method to model and simulate the PD phenomenon in VSMD systems, and develops statistical methods to understand potential insulation degradation patterns in winding insulation.