Flux Weakening Control of PM Machines with Winding Switching and Thyristor Phase Back Control

Abstract

Operation of machine for extended speed range has been an important topic of research for high speed applications of machines. This operation is achieved through flux weakening with in the machine to limit increasing back emf with increasing speed. Flux weakening in this paper is achieved through winding switching in such a way that flux of one winding opposes the flux of other winding in flux weakening mode of operation. Thyristor phase back control is used to smoothly control flux over the entire flux weakening range of the motor. Matlab simulations are performed to demonstrate the higher speed operation of PM machines through this flux weakening technique.