Performance improvement of direct torque controlled interior permanent magnet synchronous motor drive by considering magnetic saturation

The influence of magnetic saturation on the maximum torque per ampere strategy in constant torque region and field weakening strategy in constant power region for a direct torque controlled interior permanent magnet synchronous motor drive are discussed in this paper. In other words, by considering magnetic saturation, all optimal strategies and motor-inverter limitations are derived in the T - |psi_s| plane to apply in the direct torque control method. These strategies that take magnetic saturation into account and determine the optimal torque and flux commands are derived and implemented in direct torque control method. Simulation results on a prototype interior permanent magnet motor are included to validate the usefulness of the work.