Research on a novel adaptive sliding mode observer sensorless control for dual three-phase permanent magnet synchronous motors

• Sensorless position/speed estimation for DTP-PMSM is achieved. • A smooth, continuous switching function with accelerated convergence is proposed. • Current-dependent SMO gain adaptation outperforms speed-based regulation. • Enhanced position/speed accuracy surpasses conventional back-EMF methods. To mitigate the problems of signal distortion and high-frequency chattering in dual three-phase permanent magnet synchronous motor (DTP-PMSM) caused by conventional sliding mode observers (SMO) and low-pass filters (LPF), this study introduces an innovative sensorless control algorithm based on a novel adaptive SMO (NASMO). This algorithm takes into account the inductive coupling between the two winding sets of the DTP-PMSM and introduces an easily implementable new switch function to replace the traditional discontinuous switch function. Additionally, an adaptive SMO gain strategy is proposed, allowing the SMO gain to adjust according to current-related variables, ensuring fast convergence of the observer and reducing chattering. Compared to existing SMOs, this method eliminates the need for filtering and lower position estimation deviation, effectively suppresses chattering, meanwhile reduces estimation errors in rotor position, rotor speed as well as α-β axis currents. The outcomes from both simulations and experiments further validate the enhanced performance of the NASMO algorithm.