A Direct Torque Controlled Permanent Magnetic Synchronous Motor System Based on the New Rotor Position Estimation

The low speed and high torque permanent magnetic synchronous motor (PMSM) is increasingly playing an important role in electric propulsion system due to its many advantages over competing technologies. The direct torque control (DTC) technique for PMSM is receiving increasing attention due to the important advantages the low dependence on motor parameters when compared with other motor control techniques. But for successful operation of PMSM, rotor position and speed information is required. Thus, there has been an intense interest in the development of a so called position sensorless drive. In this paper, a adaptive estimation approach is developed which enable sensorless operation of the PMSM . Implementation issues for the sensorless PMSM electric drive are discussed,and experimental results are presented in order to demonstrate the effectiveness of the proposed techniques to the sensorless PMSM.