PM-Biased AC Magnetic Suspension with Energy Transfer Function(<Special Issue>the 14th MAGDA Conference)

A novel AC magnetic suspension with a permanent magnet is proposed which has the\u27 performance of noncontact energy transfer to the suspended object (floator). It uses permanent magnets for suspending the weight of the floator. An electromagnet combined with the permanent magnet operates for both stabilization and energy transfer to the floator. The principles of the proposed magnetic suspension system are clarified. It is shown that the average suspension force can be adjusted with an impedance control circuit in which the amplitude of the positive secondary current and that of the negative secondary current are separately controlled. An experimental apparatus is fabricated which has three pairs of primary and secondary electromagnets with pennanent magnets for three-axis active control in the vertical direction; the three secondary electromagnets are fixed to the floator that is a rectangular steel plate. The efficacy of the fabricated impedance control circuit is confirmed by the single-axis control experiments. By operating the three secondary electromagnets, the floator was successfully suspended without any mechanical contact.平成１８年日本ＡＥＭ学会賞「論文賞」受