PRELIMINARY CONSIDERATIONS ABOUT THE ADOPTION OF UNCONVENTIONAL MAGNETIC MATERIALS AND STRUCTURES FOR INDUCTION MOTORS

Abstract

ABSTRACT The activity carried out and presented in this paper deals with the opportunity of utilizing high quality magnetic materials, such as amorphous, microcristalline or cubic texture materials for the magnetic structure of medium size induction motors. In order to evaluate the benefits introduced by these materials for reducing the iron losses in a.c. motors, digital preliminary computations have been carried out considering the characteristic of such materials (Induction versus specific losses) and the obtained results for each solution have been compared. At the present, however, the; above mentioned materials are costly, not easy to handle and to assemble and therefore a practical solution with grain oriented steel in a crossed structure obtained alternating sheets with orthogonal grain orientation, in order to simulate the cubic texture material (i-oriented material) has been proposed. To verify the obtained theoretical results with the digital computations, a prototype of 20 Hp, 380 V, three phases induction motor with this non conventional magnetic structure has been designed and built. The tests on the prototype to evaluate the iron losses are in good agreement with the digital simulation results.