NOMENCLATURE

Abstract- In this paper the theory of direct torque control (DTC) in permanent magnet synchronous motor (PMSM) is investigated. The effect of zero voltage vectors on the performances of the PMSM DTC drives is analyzed. Different from the conventional switching table eliminating zero voltage vectors, a novel switching table using zero voltage vectors is proposed. Simulation results show that the PMSM DTC drives work properly under the control of the table. The advantages of the novel switching table are given compared to other switching tables for the DTC in PMSM