Influences of Magnet Arrangements on Air-Gap Field Modulation Effects in Interior Consequent-Pole PM Machines
Ya Li, Hui Yang, Heyun Lin, Shichuan Ding, Jun Hang, Wei Li
Abstract
This article comprehensively investigates and compares the influences of permanent magnet (PM) arrangements on air-gap field modulation effects (AFMEs) in interior consequent-pole PM (ICPM) machines. Four typical single-layer PM structures, i.e., flat-type, spoke-type, U-shaped, and V-shaped magnet designs, are exemplified in order to identify how different rotor structures perform AFMEs due to a double-side slotting and affect the torque behavior. The contributed torque components and corresponding torque proportions of the main air-gap flux density working harmonics are quantificationally distinguished by adopting the Maxwell stress tensor (MST) method. It shows and confirms a fact that the flat-type and V-shaped ICPM cases present the lowest and the highest torque proportions due to their AFMEs, respectively. In addition, the influences of rotor PM parameters on AFMEs of the four single-layer ICPM machines are subsequently studied. Finally, the prototype of the ICPM machine with V-shaped PM structure is manufactured. The corresponding experimental results are conducted to validate the theoretical and finite element (FE) analyses.