Low speed performance improvement of a direct torque controlled interior permanent magnet synchronous machine drive

In order to achieve good steady-state and dynamic performance, the flux estimation is the key of a direct torque controlled (DTC) drive, especially at low speed. The effects of the stator resistance variation of the stator resistance and the forward voltage drops of the power switches are analyzed and compensated in a DTC drive in this paper. Modeling and experimental results confirm the effectiveness of the proposed flux estimator.