Chapter 5 - Vector control of alternating current motors

Abstract

This chapter introduces the vector control for the instantaneous torque of alternating current (AC) motors. First, by reviewing the instantaneous torque control of direct current (DC) motors, the concept for the instantaneous torque of AC motors is explored. Direct vector control and indirect vector control are introduced as two techniques of the vector control for an induction motor. Flux estimation methods to obtain the rotor flux angle required for the vector control of an induction motor are examined. Typical open-loop rotor flux observers by using the voltage model, current model, and combined method are introduced as the flux estimation methods. In the case of permanent magnet synchronous motors the vector control for surface-mounted permanent magnet synchronous motors (SPMSMs) and interior permanent magnet synchronous motors (IPMSMs) are explored separately. In the vector control of SPMSMs and IPMSMs the MTPA operation that produces the maximum torque per ampere is explained.