FEM-based design of an induction motor's part winding to reduce the starting current

The goal of this research is designing the part winding of an induction motor in order to reduce the surge currents when starting. The analyzed motor is to be built for special compressor applications; therefore, the standard star-delta windings are inappropriate. Until recently, winding schemes have been chosen using different analytical and experiential criteria. In this paper, a design process is presented based on transient numerical analysis with the rotation of the rotor also taken into consideration. The developed numerical model enables a study of the motor's performance under arbitrary load conditions, and, thus, the entire torque characteristics of the motor can be predicted. Furthermore, the effects of eddy currents in the motor shaft material and their influence on the magnetic field and the motor's performance have been analyzed. The numerical results have been verified by laboratory measurements.