Self-compensation of unbalancing for induction motors drive system based on a quasi time-invariant model

An induction motor drive system that has the ability to compensate stator winding coil turns unbalancing is studied. The proposed drive system exhibits smooth torque when the machine operates either under indirect field oriented control or based on the standard volts/hertz scheme. The proposed solution requires the derivation of a symmetrical model for representing an unbalanced induction motor and the design of a control law to compensate the stator winding unbalancing. Extensive theoretical analysis and experimental tests are provided to demonstrate the feasibility of the proposed solution.