Research On Working Characteristics Of Weak Coupling Radial Magnetic Bearings

Maglev is one of supporting technology which use controllable electromagnetic force to support a rotor. There are variety kinds of couplings in a magnetic suspended rotor system, one natural characteristics of which is multi-coupling. In practice these magnetic couplings makes the accuracy of the rotor position estimated from electrical signals worse. The control precision and dynamic response of the rotor is important factor of its extensive development. But many control systems of magnetic bearings controls each magnetic pole, without considering the coupling of each magnetic pole. When the rotation speed and control precision of the rotor is not high enough, ignoring the coupling of the magnetic pole is feasibility. In recent years, with the higher and higher rotation speed and rotation precision of magnetic rotor, a high performance magnetic suspended rotor system is greatly needed, which the coupling of each magnetic pole can't be ignored. There are two ways to weaken the affect of magnetic pole's coupling, one is by control system, the other is by structure. For the theory of maglev is immature and the multi-coupling of the magnetic suspended rotor system, it's still hard to do it by the control system way.The research utilizes the characteristic of low frequency magnetic field which attenuates quadratic as the distance increase. The research focused on the different structure design of the magnetic bearing, to weakening magnetic coupling by means of disconnection magnetic path of each magnetic pole in the magnetic bearing. For this reason it is so called loose coupling magnetic bearing. The research analysis the magnetic pole's coupling of E-type and C-type by ANSYS. The research analysis the rotor's different coupling affect between different structural under the condition of the rotor's different power state and motion state. The characteristics of tow kinds of loose coupling magnetic bearing are studied. The loose coupling characteristic of the magnetic bearing under different working conditions is studied and validated. The coupling mechanism and coupling model of the loose coupling magnetic bearing is discussed and set up. The influence of structural parameters on coupling characteristic is analyzed. The manufacturing process of the loose coupling radial magnetic bearings is also studied.The research derived the capacity formula of E-type radial magnetic bearings by the basic magnetic field theory, based on which the research analysis the design of structural parameters of E-type. It provides a completely design guidelines for loose coupling magnetic bearings.At last, based on the summary of this dissertation, the developing trend of magnetic pole's coupling in radial magnetic bearings is prospected.