The Transactions of the Korean Institute of Electrical Engineers B (대한전기학회논문지:전기기기및에너지변환시스템부문B)

The Korean Institute of Electrical Engineers (대한전기학회)
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Comparison on the Airgap Flux Density of High-Speed Slotless Machines with Radial Magnetization and Halbach Array PM Rotor

반경방향 착자형과 Halbach 배열형 영구자석 회전자를 갖는 고속 슬롯리스 기기의 공극자속밀도 특성 비교

  • Published : 2001.07.01
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Abstract

High speed brushless permanent magnet(PM) machines need a key technology to minimize the iron core losses in stator and the eddy current losses in the retained sleeve and magnets caused by slotting harmonics. Thus, slotless or iron-coreless brushless PM machines have been applied for a very high rotational speed and/or the ripple-free torque. Unfortunately, slotless or coreless PM machines have lower open-circuit field than slotted and/or iron-cored types, which cause to reduce power density. Fortunately, Halbach array can generate the strong magnetic field systems without additional magnetic materials. In this paper, the 4-pole Halbach array is applied to the high speed machine and is compared with the radial magnetized PM array in field system. The iron-/air-cored stator of PM machine is constructed with/without winding slots. Open circuit magnetic fields of each type are presented from the analytical method and finite element method. Consequently, it is confirmed that the Halbach array field system with slotless stator is more suitable to the high speed motor because it has high flux density, sinusoidal flux distribution than others.

Keywords

References

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