A polar coordinate-oriented method of identifying rotor flux and speed of induction motors without rotational transducers

In this paper, we propose a novel method of identifying rotor flux and speed of induction motors. Our identification algorithm does not involve any pure integration operations, which have been a main source of performance deterioration in most of prior works. This is made possible by formulating the identification problem in the polar coordinate frame. It does not contain any parameters which need to be retuned according to H/W configurations or operation conditions. Moreover, the rotor speed does not have to vary slowly for the convergence of the estimation error. Some experimental results as well as a rigorous convergence analysis are presented to demonstrate the practical use and generality of our identification method. For our experimental work, we have built a prototype drive system, in which all identification and control algorithms are implemented digitally on a DSP