State-space flux-linkage control of bearingless synchronous reluctance motors

This paper deals with a model-based state-space flux-linkage control of a dual three-phase-winding bearingless synchronous reluctance motor. Analytical tuning rules for the state feedback, integral action, and reference feedforward gains are derived in the continuous-time domain. The proposed method is easy to apply: the desired closed-loop bandwidth together with the estimated magnetic-model of the motor are required. Furthermore, the proposed method automatically takes into account the mutual coupling between the two windings. A simple digital implementation is provided and the robustness of the proposed control method against the system parameter inaccuracies and eccentric rotor positions is analyzed. The proposed controller design is evaluated by means of simulations by keeping in mind the most important aspects related to an experimental evaluation.