Degradation of winding insulation under partial discharge

摘要

The electric stress from fast front repetitive pulse voltages on the winding insulation in a pulse width modulated (PWM) inverter driven induction motor is much more severe than that from conventional sinusoidal voltages. To prevent winding insulation degradation under the partial discharge that can result from voltage overshoots, this paper will discuss the effect of winding geometry, varnish and winding insulation materials on partial discharge inception voltage.