Analysis and simulation of a 7-phase PM bearingless motor

A multiphase bearingless motor with single set of winding has simpler construction, higher power ratings with lower voltage limited devices and better fault tolerance. Additionally, comparing with the traditional surface-mounted PM rotor configuration, there are more advantages for the interior PM rotor configuration, such as, larger suspension force with the increased inductance of suspension winding, avoiding the falling-off of PM during the high speed revolving. Taking a 7-phase interior PM bearingless motor (IPMBLM) for example, the derived general analytical model of inductance matrices is proposed and FEA simulation results validated the proposed model. Additionally, the SIMULINK simulation results certify the feasibility of the IPMBLM.