A New Stator-Flux-Oriented Speed-Sensorless Control Algorithm for General Purpose Induction Motor Drive

Abstract

This paper proposes a new scheme for speed-sensorless control of an IM for general purpose drive applications. The scheme combines both field oriented and V/f techniques. The V/f technique used here is based on the instantaneous stator-flux space vector control method. The PWM principle made it possible to maitain the amplitude of the stator-flux space vector constant while commanding its rotation speed such as to generate the desired torque. The principle of speed and torque control is based on the field orientation of a d-q rotating frame. In such a case, an equivalence between the current control and the torque control is achieved. The control system was tested at different operating conditions and the experimental results have shown good motor characteristics during transients as well as in steady states.