Topologies and analysis of flux-modulation machines

In this paper, one new machine family, i.e. named as flux-modulation machines which produce steady torque based on flux-modulation effect is proposed. The typical model including three components-one flux modulator, one armature and one excitation field exciters of flux-modulation machines is built. The torque relationships among the three components are developed based on the principle of electromechanical energy conversion. Then, some structure and performance features of flux-modulation machines are summarized, through which the flux-modulation topology distinguish criterion is proposed for the first time. Flux-modulation topologies can be further classified into stationary flux modulator, stationary excitation field, stationary armature field and dual-mechanical port flux-modulation machines. Many existed topologies, such as vernier, switched flux, flux reversal and transverse machines, are demonstrated that they can be classified into the flux-modulation family based on the criterion, and the processes how to convert typical models of flux-modulation machines to these machines are also given in this paper. Furthermore, in this new machine family, developed and developing theories on the vernier, switched flux, flux reversal and transverse machines can be shared with each other as well as some novel topologies in such a machine category. Based on the flux modulation principle, the nature and general theory, such as torque, power factor expressions and so on, of the flux-modulation machines are investigated. In additions, flux-modulation induction and electromagnetic transmission topologies are predicted and analyzed to enrich the flux-modulation electromagnetic topology family and the prospective applications are highlighted. Finally, one vernier permanent magnet prototype has been built and tested to verify the analysis results.