Method for the Prediction of the Potential Distribution in Electrical Machine Windings Under Pulse Voltage Stress

Abstract

This article provides an applicable method to predict the distribution of the electric potential inside the winding of an electrical machine with a reasonable set of parameters. It extends the understanding of the winding impedance in terms of the inter-winding behavior and gives us the opportunity to properly design the insulation system during the development phase of an electrical machine. Predictions are backed up by measurements and an in-depth look at the measurement setup. The results proof nonuniform potential distribution and show that the potential difference between individual turns exceeds the amplitude of the phase voltage. Our findings also establish an interrelation between the winding impedance and the potential oscillations inside the winding. The article provides an introduction to the fundamental process of voltage stress on electrical machine windings and discusses drivers for upcoming challenges in the field of winding insulation and partial discharges.