Analysis and Design of a New Type of Less-Rare-Earth Hybrid-Magnet Motor With Different Rotor Topologies

In this paper, a new type of less-rare-earth hybrid-magnet (LRE-HM) motors are design, analysis, where two types non-rare-earth ferrite-PM and rare-earth NdFeB-PM materials are involved. According to the proposed general design rules and requirements, three different rotor topologies, namely series, parallel and series-parallel mixed connections of magnetic circuit forms are evolved. And the design procedure of the new type of the LRE-HM motor is implemented in detail, where the series-parallel connection is acted as the design example motor. The corresponding electrometric performances of the three motors are investigated and compared. Both the theoretical analysis and electromagnetic performances demonstrate the effectiveness of the proposed design principle of excitation source equivalence and the LRE-HM motors. By incorporating both rear-earth PM and non-rear-earth ferrite PM materials in the rotor, the proposed LRE-HM motors can not only offer the comparable electromagnetic performances with the baseline motor, but also has the unique advantages of less consumption of rear-earth PM material and lower PM cost.