Position Sensorless Control of Dual Three-Phase PMSM Based on Improved Sliding Mode Observer

This paper presents an improved sensorless control system for dual three-phase permanent magnet synchronous motors (DTP-PMSMS), aimed at overcoming the limitations of conventional sliding mode observer (SMO) algorithms. Conventional SMO algorithms frequently encounter chattering and reduced accuracy caused by motor parameter variations, such as changes in phase resistance and inductance. The proposed method enhances the conventional SMO by incorporating an S-shaped switching function, which can significantly reduce chattering. Moreover, an online parameter identification method based on a model reference adaptive system (MRAS) is integrated into the control system. The dynamic adaptation of motor parameters ensures stable and precise position estimation. Compared with conventional SMO algorithms, the improved method demonstrates superior accuracy and robustness, even under motor parameter variations.