An Accurate Magnetic Equivalent Circuit Model for Modeling and Analysis of Variable Reluctance Energy Harvesters

Variable reluctance energy harvester (VREH) is a good candidate of transducers to transform the environmental energy into electricity. VREHs act based on electromagnetic induction due to the variation of air-gap reluctance with the rotation of wheel. This paper presents an accurate analytical model based on magnetic equivalent circuit (MEC) model and conformal mappings (CMs) for electromagnetic modeling the VREHs, which have a large air-gap. The geometry of analyzed VREH on both sides of air-gap including the iron parts, slots, and permanent magnets (PMs) is divided into many elements in cylindrical coordinate, and each element is then replaced with an equivalent permeance model. The air-gap region is modeled with permeances calculated by the CM method, which can accurately consider the real paths of flux tubes in large air-gap. The obtained air-gap permeances are then used in MEC model for electromagnetic modeling and analysis of studied VREH, while considering the effects of slots and magnetic saturation, accurately. In final, the analytical results are verified by comparing with the corresponding results obtained through finite element method (FEM).