Evaluation of Improved SMO Control of SPMSM under DTC Scheme

This paper proposes an improved Sliding Mode Observer (SMO). Compared with the traditional SMO, it can estimate position and speed information of the rotor more accurately. Its stability is proved by Lyapunov Stability. A control scheme of Permanent Magnet Synchronous Motor (PMSM) under Direct Torque Control (DTC) is designed, using the improved SMO as the feedback of speed information. The results show that the proposed method works well without position encoder. The improved SMO guarantees DTC scheme quick response and strong robustness.