Effects of magnetic saturation on radial force of bearingless synchronous reluctance machines

The effects of magnetic saturation on radial force production in synchronous reluctance type bearingless motors are discussed. MMFs are calculated and flux densities are derived with approximated magnetic saturation curve. The radial force is almost proportional to the difference of squared flux densities. The maximum radial force is limited by magnetic saturation. To achieve maximum radial force, motor excitation has to be set to an optimal value. The force constant (radial force/radial force winding current) can also be maximized at the optimal excitation. The maximum radial force value is derived.<>