IE3 Efficiency Induction Motors with Aluminum and Copper Rotor Cage: Technical and Economic Comparison

The aim of this study was to design three-phase induction motors with aluminum and copper cage, in the range 0.75 22 kW, to fulfill the IE3 efficiency level according to typical performance and standard constraints. The proposed study has concerned TEFC ( totally Enclosed Fan-Cooled ), 400 V, 50 Hz, S1 duty three phase squirrel-cage induction motors only. The motors’ designs, with Al and Cu cage, have been optimized in order to reach the minimum efficiency level IE3 at lowest active material costs and satisfy the physical and performance constraints of the designs, which are the motor specifications. A suitable optimization procedure has been used which allowed to find the “best design” by chancing the geometric dimensions of the stator, rotor shape, the stator winding and the stack length. In order to guarantee the goodness and feasibility of the optimized designs, several constrains have been imposed.