Efficiency improvement on PMSM twelve sectors DTC system

After establishing the permanent magnetism synchronous machine (PMSM) twelve sectors direct torque control (DTC) platform, in this paper, the relation between torque and minimum stator currents while maximum torque per ampere (MTPA) is deduced using Lagrange multiplier method, and the optimal excitation current is obtained using the curve fitting method, and then the optimal stator flux instruction value is given, which overcomes the excessive excitation loss of constant flux given system. Simulation results show that this control strategy can not only keep good performance, but also improve operation efficiency.