Robust Adaptive Sensorless Control for Permanent-Magnet Synchronous Motors

A sensorless algorithm is developed on the basis of a rotor flux observer in the stationary frame. In particular, it involves a parameter adaptive algorithm for an initial rotor flux like the observer, which was recently proposed by Bobtsov et al. (Automatica, vol. 61, Nov. 2015). In the proposed method, the flux observer is linked to the parameter estimator via a compensating term that results from parameter error. This method has a robust property against dc bias errors, i.e., it cures the inherent weakness of the pure integrator (flux observer) to dc offsets that frequently occur in current measurements and voltage estimates. The robust performance is demonstrated through simulations and experimental results.