Rotor Flux Observer Design for an Induction Motor Based Behavioural Speed Model

In this paper, we present a novel speed-sensorless flux observer design methodology for induction machines based on the measurements of the stator currents and voltages. We start with the well-known
$\alpha-\beta$
model of induction motors. We utilise a change of coordinates to transform the
$\alpha-\beta$
model into a reduced order
$(3^{rd})$
model expressed in terms of complex differential equations. As results, the analysis of the model and the synthesis of observers are made simpler. After that, we formulate a behavioural model of the rotor speed of the induction motor which we use for the synthesis of the flux observer. The potential and practicality of the proposed flux observer is demonstrated via various simulation results