Experimental verification of a technique for the real-time identification of induction motors based on the recursive least-squares

This paper presents the experimental application of a technique for the real-time identification of induction motors whose theoretical and numerical analysis had already been faced up to by, the authors in previous works. The presented identification technique, based on least-squares, reveals itself suitable to be applied to induction motors both supplied by the electrical grid and as a part of a high performance electrical drive with any control system, and thus with any, supply condition. The paper shows that the estimation of the electrical parameters of the motor can be performed by unconstrained minimisation, indirectly taking into consideration the constraints which inevitably arise when the well-known stator and rotor voltage equations are rearranged so as to allow the application of the least-squares method. Then it shows the assumptions under which this technique is valid as well as the identifiability, criteria both for transient and steady-state conditions. However the totally innovative part of this work is the presentation of the experimental results of the presented methodology as well as the description of the test bench suitably built for this purpose. The experimental results obtained by the implementation of the identification technique on a DSP confirm the theoretical and numerical results already obtained.