Sensorless HOSM Control based VGE Observer for a 7-Phase PMSM

This paper proposes a new sensorless control scheme based on the super twisting observer with an added varying gain exponent, and the higher order sliding mode controller for a non-sinusoidal seven phase Permanent Magnet Synchronous Machine (PMSM). This strategy is based on the splitting of the seven phase into mechanically coupled, but electrically independent machines. Only select harmonics of the machine are considered for both the position, speed estimation and control. To the best of our knowledge, the proposed observer and controller have not yet been applied to this machine type, they overcome the classical observers/controllers limitations linked to the perturbation and noise effects. Stability analysis of the proposed observer and controller is conducted and simulation results are shown at the end to highlight the feasibility of the proposed observer-controller scheme.