Magnetic Property Distribution of a Wound Laminated Stator Core by Ultra-thin Electrical Steel Strip for a Dual-Axial Gap High-Speed Induction Motor

Next-generation high-speed motors are required to be compact and offer high power density, high efficiency, and low loss. Reducing the thickness of the electrical steel sheet that constitutes the stator core is particularly effective in reducing eddy current losses. For this purpose, ultra-thin electrical steel sheets with a thickness of 0.08 mm were manufactured. However, it is very difficult to manufacture stator cores by laminating sheets fabricated by punching such ultra-thin electrical steel sheets because large numbers of punched sheets are required. Therefore, we constructed a stator core by winding a ribbon-shaped ultra-thin electrical steel strip into a spiral shape. We then measured the circumferential distributions of the magnetic properties of this prototype stator core. It was confirmed that this core provides significantly reduced eddy current losses and uniform distribution of its magnetic properties in the circumferential direction when compared with conventional stator cores manufactured by punching and laminating.