Sliding mode direct torque control with new integrator for stator flux estimation in IPMSM

A sliding mode controller for interior permanent magnet synchronous machine (IPMSM) is investigated in this paper, in which direct torque control (DTC) concept, variable structure control and space vector modulation (SVM) are integrated to achieve high performance. It features in very low flux and torque ripple and almost fixed switching frequency. A new integration algorithm for estimating stator flux is introduced. The simulation results show that the flux and torque ripples are greatly reduced when compared with those of the basic DTC. The fast response and robustness merits of the basic DTC are still preserved. In addition, fixed switching frequency at different operating conditions becomes possible.