Behaviour of Rotating Field in Slip-Ring Induction Motors with Chopper Control.

Document Type : Research Studies

Author

Assistant professor, Electrical Power & Machines Department, Faculty of Engineering, Mansoura University, Mansoura, Egypt.

Abstract

Stator currents of slip-ring induction motor having chopper control in the rotor circuit, are no more sinusoidal.
The analysis of the air-gap resultant field , due to such currents , results in a different expression for the established rotating field. The derived expression is examined in order to study the rotating field behavior under chopper control. In addition to some of the well known behaviours , a new one had been distinguished and proved by constructing the geometrical pattern of the air-gap resultant field.
An effective winding factor is introduced to give the effect of nonsinusoidal stator currents on the magnitude of the resultant m.m.f. harmonics.

Main Subjects