Equivalent Circuit of PWM-Fed Induction Machine With Damper Winding for Noise and Vibration Reduction

This paper presents a system that enables the passive reduction of noise and vibrations in a three-phase induction machine with a stator damper winding connected to capacitors. This is a simple and effective system for reducing the flux density harmonics in an electrical machine. The theoretical study is based on the modeling of a machine equipped with the damper winding obtained from Kron's theory about equivalent circuits of electrical machinery. The analysis of the equivalent circuit allows one to identify possibilities to reduce the flux density harmonics responsible of unwanted noise and vibration components. Finally, an experimental validation is performed.