A Magnetic Bearing Switched Reluctance Motor With Simultaneous Excitation by a Modified Half-Bridge Converter

Abstract

This paper presents a novel magnetic bearing switched reluctance motor (SRM) (MBSRM) with two degrees of freedom suspension, consisting of an SRM and an active magnetic bearing (AMB). In the proposed MBSRM, three-phase armature windings of the SRM and a biased winding of the AMB are fed together by a modified asymmetric half-bridge converter. The rotational torque in SRM and the biased flux used for producing electromagnetic force in AMB are generated simultaneously when the MBSRM works on the traditional switched reluctance excitation mode. First, the structure and working principle of the MBSRM were introduced. Second, its theoretical formulas of suspending forces were given and validated with the finite element analysis. Third, the proposed half-bridge converter is shown, and currents in the biased winding and three-phase armature windings of MBSRM are obtained by the magnetic field–circuit coupling simulation. Moreover, a prototype is manufactured and the experiment results have proved the feasibility of the proposed converter.