Application issues for PWM adjustable speed AC motor drives

In this article, some application issues for adjustable speed AC motor drives have been investigated. The effects of high PWM frequency, or high dv/dt on the motor terminal voltages and bearing currents have been addressed and explained. Mitigation techniques have been shown to significantly reduce the transient peak voltage and dv/dt at the motor terminals, as well as within the motor windings. This reduction contributes to improved reliability of PWM motor drive systems.