LAUSR

The bridge of the interior permanent magnet (IPM) machine can reduce the leakage of the machine, which makes the utilization rate of the permanent magnet (PM) improved. However, the asymmetric saturation in the bridges will cause the asymmetry distribution of the magnetic potential on the rotor surface, which will bring challenges to the accurate calculation of inductances. Excited by the armature current at different initial phase angles, the flux distributions in the bridges are analyzed. Meanwhile, the reason why the asymmetric saturation exists in the bridges is revealed theoretically. Based on the above analysis, the rotor magnetic potential (RMP) model for an IPM machine with the bridges is established and used to calculate the armature reaction magnetic field and inductances of the IPM machine. In this paper, the RMP distribution in the bridges is obtained by considering asymmetric saturation, so the RMP model can reflect the rotor surface magnetic potential distribution more accurately, which is evident from the adjacent degree between the calculation results and the finite-element analysis (FEA) ones.