Simulation and Experimental Analysis of a Mechanical Flux Modulated Permanent Magnet Homopolar Inductor Machine

A permanent magnet homopolar inductor machine with a mechanical flux modulator (PMHIM-MFM) for flywheel energy storage system (FESS) is investigated. The no-load air-gap flux generated by the PM can be suppressed, and the no-load core loss can be reduced by using the MFM when the PMHIM-MFM works at an idling state, which helps to improve the energy transformation ratio of the FESS. First, the operation principle and flux modulation mechanism of the PMHIM-MFM are presented. Second, the influences of MFM shapes and structure parameters, moving distances, and the eccentricity on the electromagnetic characteristics of PMHIM-MFM are investigated based on the 3-D finite element method (FEM). Third, the simplified equivalent analysis model of the PMHIM-MFM is proposed to analyze the flux weakening ability and magnetic pull of the MFM. Fourth, the characteristics of the armature reaction of the PMHIM-MFM are investigated, and the load performance is studied. Finally, a prototype of the PMHIM-MFM is tested, and some theoretical analyses and FE calculations are validated.