A novel control scheme for wide speed range operation of direct torque controlled synchronous reluctance motor

This paper proposes a novel control scheme for wide speed range operation of synchronous reluctance motors. The proposed scheme consists of a combination of maximum torque per ampere control, maximum torque per flux control, flux-weakening control and torque limiting. These controls are based on a mathematical model in a rotating reference frame that is synchronized with the stator flux linkage. The proposed control scheme is suitable for direct torque control or flux-oriented control. The validity of the control scheme is verified by the experimental results. The proposed schemes of flux weakening and torque limiting are insensitive to parameter variation.