Magnetic Properties of Wound Laminated Cores for a Dual-Axial Gap Induction Motor Under PWM Excitation

In recent years, the demand for advanced electric motors has increased as researchers aim to improve the performance of robots and mobile equipment. Therefore, we have developed a high-speed, high-efficiency, three-phase eight-pole dual-axial gap induction motor. Because this new motor is driven using a pulse width modulation (PWM) power supply that operates at high modulation and carrier frequencies, stator cores and rotor cores that offer particularly low eddy current losses are required. To reduce the eddy current losses, we have developed a new wound laminated core structure for this motor by winding a 0.08-mm-thick ultra-thin electrical steel strip. The proposed new core is called a “wound laminated core”. This wound laminated core demonstrated extremely low eddy current losses at high frequencies and harmonics under both sinusoidal wave excitation and PWM excitation. Therefore, this wound laminated core represents an excellent stator core material structure for use in high-speed, high-efficiency motors.