Improved sensorless operation of interior PM brushless AC motor drive with reduced-order EKF

It is a challenge to realise an EKF-based sensorless controller for an interior permanent magnet (IPM) brushless ac motor drive due to the influence of non-linearity and rotor saliency. An improved reduced-order EKF method is presented which reduces the rotor position estimation error of an IPM motor, which was evident in [1] due to the neglect of saliency. The effectiveness of the proposed method is verified experimentally.