Designing and Optimizing Novel Hybrid-PM Variable Flux Machines

This paper proposes two novel hybrid permanent magnet variable flux machines (hybrid-PM VFMs). Neodymium Iron Boron (NdFeB) PM is utilized as a HighCoercive-Force (HCF) PM in both machines, while AlNiCo and the new PM Iron Nitride (FeN) are utilized as a Low-Coercive-Force (LCF) PM in the first and second machines, respectively. The Demagnetization Ratio (DR) of LCF PMs with different sizes is explored in this paper. Moreover, 2D FEA designs are developed to investigate the potential for enhancing the electromagnetic performance in the machines. The flux density (B) is calculated based on the equivalent magnetic circuits (EMC) of both machines and the outcomes are assessed with the FEA results under different operation conditions. An optimization process is used for both designs and the outcomes are compared to the Nissan Leaf conventional baseline IPM design machine. Furthermore, efficiency maps will be provided at various levels of demagnetization.