An Accurate Model by Using the Legendre Polynomial Functions of a Dual Stator Induction Machine Dedicated to the Static Eccentricity Diagnosis

The induction machine takes a preponderant place in many industrial applications due to its low cost and to its robustness. Nowadays, there are several standard schemes for the control of that kind of machine. In order to release a power segmentation and to increase the reliability, many engineers suggest to use multi-phase supplies. Furthermore, they advocate the dual stator winding induction machine (DSWIM), in which the two three phase stator winding systems are shifted by any angle. The main purpose of our investigation is to propose two models of the DSWIM under static eccentricity by using two shapes of the air- gap function and their associated permeance functions. The first method uses a classical form of the air-gap function. The second one gives a novel expression of the air-gap function involving a Legendre polynomial development that is obtained thanks to a geometrical study of the permeance function. Simulated and experimental set-up will prove the effectiveness of both models by choosing the Motor Current Signature Analysis (MCSA) as the diagnosis tool.