Innovative Design for Flux Leakage Reduction in IPM Machines

This paper presents a novel rotor design for interior permanent-magnet machines. The advantage of this solution is the near elimination of magnetic flux leakage in the rotor iron bridges, which represents the main disadvantage of this machine topology. Therefore, enhanced magnet utilization results from the new rotor arrangement. This concept is accomplished by utilizing non-magnetic wedges to lock the magnet in a robust rotor structure. This paper is supported by both electromagnetic and mechanical finite-element method analyses. Significant results of this investigation are presented and discussed in this paper. A machine prototype with the implemented innovative rotor design was manufactured and tested for the validation of the finite-element simulations. Several manufacturing methods of the wedge have been investigated in order to evaluate the resultant wedge characteristics and in order to assess the feasibility of mass production. The total cost analysis yields potential machine cost reduction.