Impedance Matching for an Inductive Harvesting Transducer

This paper presents an inductive transducer coupled to an articulated device for harvesting applications. This device, taking advantage of the sway of the waves of the sea, produces a linear oscillating motion in a solenoid-magnet. Using some magnetic fundamentals, a model of the transducer is deduced. This model is then extended to a harvesting device made with three transducers. Different transducer prototypes, with different number of coil turns, wire gauge, and magnets, have been developed to optimize it. The energy harvested form the final transducer array is processed electronically to charge an autonomous system battery. To maximize the energy collected the principle of impedance matching is used. Thus, the output impedance of the transducer array must match the converter input impedance. A buck-boost hybrid converter (HBB) controlled to behave as a Loss Free Resistor is proposed as impedance adaptor circuit. After the theoretical analysis, several simulation and experimental results are given.