Experimental studies on the effect of shunted electrical loads on the performance of a vibration-based electromagnetic energy harvester

Abstract

At present, the researchers are grappling with the problems of maximizing the output power from a vibration-based electromagnetic energy harvester (VBEH). The parameters affecting the VBEH output power are: electrical damping ratio (ze), mechanical damping ratio (zm) and load impedances of shunted electrical load. Therefore, in this work, the experimental studies are carried out to study the effect of shunted electrical load on: i) the power output of VBEH and, ii) the determination of ze which maximizes the output power. For this purpose, a VBEH is designed and developed to obtain high open-circuit voltage. The effect of resistive, inductive, and capacitive loads on output power of VBEH is investigated using experimental setup developed exclusively for the same. The experimental results reveal that the output power of VBEH is maximum: i) at the resonant frequency ii) when equivalent resistive load impedance equals the internal resistance of electromagnetic coil and iii) value of ze is very small when compared to zm.