Design of Torque Exciter for Induction Machine

Abstract

Three phase induction machines are becoming more popular and are also being used as variable speed drives. An induction machine driving a load represents a torsional system. The analysis of any torsional system without active damper is somehow based on conventional method i.e. including shaft stiffness and viscous damping provided by the material. This conventional method might lead to somehow highly compromised results. The involvement of induction machine complicates the approach by contributing to both stiffness and damping in the system. So, in-order to verify the contribution from the electromagnetic system in overall torsion dynamics of the drive train, a thorough study on torque exciter has been carried out in this master's thesis work. A new type of excitation system has been proposed on the basis of studied material. A careful investigation on stability of the proposed excitation system has also been performed followed by laboratory set-up and testing. Finally, measurements were carried out to verify the electromagnetic system's contribution toward both stiffness and damping. A brief comparison between simulation results with measurement result has been presented.