A new control method of bearingless switched reluctance motors using square-wave currents

Bearingless switched reluctance motors have the combined characteristics of synchronous motors and magnetic bearings. Radial force production for rotor shaft magnetic suspension is explained with differential stator windings composed of the motor main windings and radial force windings. In this paper, a new control method with square-wave currents in the motor main windings is proposed. Under every condition, from no load to full load, stable operation is realized by opportunely controlling the advanced current phase angle θ_m , and the current pulse width θ_m with the new control method. The rotational torque produced by the radial force winding currents is also considered in the new control method. It is shown in experimental results that a proposed method is very effective for stable operation at no load