Estimating the Impact of Pulse Voltage Stress Caused by Modern Power Electronics Technology on Machine Winding Insulation Material

Abstract

In this paper the influence of the voltage step on the turn-to-turn insulation is investigated when using silicon carbide (SiC)-MOSFET. As already known, the steep voltage gradient dv/dt by using of the modern inverter semiconductor devices leads to additional stress on the stator winding insulation system, especially the turn-to-turn insulation. The transient voltage distribution within the stator winding is measured to determine maximum stress on turn-to-turn insulation. Changing the values and distribution of the inter-turn capacitances it is possible to identify the influence of this parameter on the turn-to-turn insulation stress. Using the measurement results it is possible to define a maximum allowable voltage gradient in order to keep the turn-to-turn insulation within its specified safe operating range.