Vector control of single-phase induction machine with maximum torque operation

By the advent of power electronic and microelectronic devices, together with their steadily cost reduction, single phase induction motors (SPIMs) are increasingly considered as variable speed drives in recent years. Vector control proved to be practical and effective in these drives. However, winding asymmetry in SPIMs causes extra coupling between two stator windings and time varying terms, and resulting in an unbalanced machine operation. In this paper a symmetric model of SPIM with no extra coupling and time varying terms is obtained. An indirect vector control system based on maximum torque per ampere strategy is then proposed. It is shown that the proposed scheme substantially improves the motor torque.