MRAS-based speed sensorless control for induction motor drives using instantaneous reactive power

MRAS-based techniques are one of the best methods to estimate the rotor speed due to its performance and straightforward stability approach. The adjusting signal driving the adaptation mechanism may be a function of the flux, of the back EMF, or of the outer product of stator current and the back EMF. Each technique has advantages and drawbacks. In this paper, the authors propose a MRAS based speed estimation scheme for IM drives using instantaneous reactive power. First, a function equivalent to the instantaneous reactive power of the system is employed and the error between its measured value and the estimated one is then utilized in the speed adaptation mechanism. The design of the adaptation mechanism and some basic experimental results are presented and discussed. The technique has a superior robustness to the parameter variations as compared to other MRAS-based techniques proposed in literature.