Design of Wound-Field Rotor Synchronous Motor for Electric Vehicles using Grain-oriented Electrical Steel Sheet to Mitigate Back-Electromotive Force

This study assessed the advantages of designing a wound-field rotor synchronous motor with grain-oriented electrical steel sheet (GO-ESS). Compared with the commonly used non-grain-oriented electrical steel sheet (NGO-ESS), GO-ESS enables the motor to generate a higher torque while maintaining a similar back-electromotive force (back-EMF) under no-load conditions. Finite-element analysis confirmed the effectiveness of GO electrical steel sheet in limiting the excessive back-EMF associated with NGO-ESS, thereby enabling the entire torque from the motor to be efficiently utilized.