Lorentz Force Type Self-Bearing Motor with 2-Pole Flux Distribution for Levitation and 4-Pole for Rotation

부상용 2극과 회전용 4극 자속 분포를 갖는 로렌쯔형 자기 부상 모터

This paper introduces a Lorentz force type four-pole self-bearing motor, where the new pole arrangement of a stator is intended to function both as a synchronous PM motor and as a magnetic bearing. The Lorentz force type has some good points such as linearity of control force, freedom from flux saturation, and high efficiency unlike conventional self-bearing motors. Mathematical expressions of torque and radial force are derived to show that they can be separately controlled regardless of rotational speed and time. To verify the proposed theory, a prototype is made, where a ring-shape outer is actively controlled in two radial directions while the other motions are passively stable supposing the radial stability. Through some experiments, it is shown that the proposed scheme can provide high capability and feasibility for a small high-speed self-bearing motor.