Performance comparison of optimally designed induction motors with aluminum and copper squirrel-cages

A significant improvement in motor efficiency is expected when substituting aluminum with copper die-cast rotor in squirrel cage induction motors due to a reduction in the rotor ohmic losses. Other performance criteria, such as starting torque, power factor, and steady-state current, mall also chang e, and the motor may need to be redesigned to obtain, optimal performance. This paper compares the performance of optimally designed spuirrel-cage ind uction motors with aluminum and copper rotor bars with equivalent specifica tions. The design is optimized using three objective functions.