Modeling and optimization of an inductive magnetic harvester considering nonlinear effects

This paper presents an equivalent model of an inductive magnetic harvester, taking nonlinear effects of magnetic field into consideration. Conventional models consist of one AC voltage source in series with an inductor and are unable to predict harvester performance precisely; a more accurate approach is introduced by considering the nonlinear effects of the magnetic fields. The new model uses a magnetizing inductance and a leakage inductance rather than a single series inductor. In the proposed equivalent model, magnetizing and leakage inductance can be found by detecting flux variation in the air gap between magnets and coil cores. The finite element analysis (FEA) method is used to estimate the electromagnetic field and flux linkage of the coils. The optimum harvesting system design is only possible based on the more accurate modeling of the inductive magnetic harvester.