Direct Torque Control System of Permanent Magnet Synchronous Motor for Integrated Starter Generator of Hybrid Electric Vehicles

The basic principle of direct torque control of PMSM was analyzed. To drive the motor in a wide speed range, a direct torque control system was presented. Constant torque control was adopted when rotor´s speed was less than the rating speed, or else, the field weakening control was employed. At discrete time, the estimation of stator flux linkage was revised using the current model. The estimation error was reduced and robustness was enhanced. It is proved that fast torque response can be obtained by simulation and implementation of the control strategy.