Analytically Computing Winding Currents to Generate Torque and Levitation Force of a New Bearingless Switched Reluctance Motor

The paper has developed a new bearingless switched reluctance motor (SRM) with the same winding structure of a common SRM. In order to generate the suspending force and torque at the same time, more than two windings are used. One developed analytical model for the flux linked by a phase of the SRM, which includes the iron saturation and the fringing flux between teeth of the stator and rotor, is applied, in order to fulfill the calculation of currents. First it is used to obtain an analytical expression for the SRM' co-energy. Then equations of torque and radial forces are gotten by derivation of the co-energy for turn angle and air gap. Coupling inductances of windings are analysed in the calcualtion. Finally one finite-element-method (FEM) calculation is used to verify the effective theoretical calculation and analysis.