The insulation system of inverter-fed motors is subjected to repetitive impulse voltages, which are generated by pulse width modulation (PWM) converters, and is expected to withstand partial discharge (PD) activity during service. PD-induced dielectric breakdown becomes one of the most important reasons for premature failures of motor insulation. Therefore, the dielectric properties of insulation material used in inverter-fed motors need to be improved to meet the requirement for rapid development of applications. Many approaches have been proposed to improve dielectric properties of insulation material used in inverter-fed motors. In this chapter, we will discuss the failure mechanism, modification approaches, and their effects on dielectric properties of insulation material of inverter-fed motors.
Part of the book: Modern Applications of Electrostatics and Dielectrics