Electrical Steels and Their Evaluation for Automobile Motors

Achieving high efficiency and high torque is an important target in EV motors. This paper describes the effect of the magnetic properties of electrical steels used as core materials for synchronous motors with permanent magnets, which are commonly used as the EV traction motors. It was confirmed that electrical steels, which have high flux density and low iron loss properties can realize high motor efficiency and torque. When PWM excitation is considered, thinner electrical steels are advantageous to suppress increased loss due to higher harmonics. Based on these results, electrical steels having high flux densities and low iron losses at high frequencies were developed.