An Improved Sensorless Control Method for PMSMs with High Anti-Disturbance Ability Based on Sliding Mode Observer Super-Twisting Algorithm

To address parameter disturbances and observation inaccuracies in sensorless permanent magnet synchronous motor (PMSM) control, this paper proposes a compound sensorless control strategy integrating the super-twisting sliding mode observer (STSMO), active disturbance rejection control (ADRC), and sliding mode control (SMC). STSMO leverages the second-order sliding mode to suppress chattering and extract back-EMF accurately, enabling robust rotor position and speed observation. The speed loop adopts ADRC with an extended state observer (ESO) for real-time total disturbance compensation, while the current loop uses SMC with a saturation function to enhance dynamic response. Simulations show faster response, lower speed fluctuation, and higher position observation accuracy compared with the traditional PI control under speed steps and load disturbances, resolving chattering and anti-interference issues for high-performance PMSM drives.