This paper proposes a novel control scheme for wide-speed-range operation of synchronous reluctance motors (SynRMs). The scheme is a combination of maximum torque per ampere (MTPA), flux weakening (FW), maximum torque per flux (MTPF) controls, and torque limiting. Fig. 1 illustrates a SynRM drive system based on direct torque control (DTC). The DTC-based drive system can achieve such controls by providing reference torque and flux values depending on the operating conditions. In this paper,

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... e control laws are derived from a mathematical model in the M-T reference frame that is synchronized with the stator flux-linkage vector. As one of the proposed scheme, the MTPA control law is given by