Robust Sensorless Speed-tracking Controller for Surface-Mount Permanent Magnet Synchronous Motors

The sensorless high speed-tracking control problem for a surface-mount permanent magnet synchronous motor via stator currents and voltages measurements is tackled, by interconnecting an H-infinity-controller and a reduced order sliding-mode observer. The observer-control scheme is robust against external load disturbances. The rotor position and speed variables are estimated in finite time by means of a reduced order observer. Thus, an output-feedback H-infinity-controller is designed such that the undisturbed system is uniformly stable around the desired speed reference, whereas the effects of the disturbances are attenuated. The feasibility of the proposed robust sensorless controller is supported by numerical simulations.