The Experimental Analysis of a Vibration Based 2D of Piezoelectric Energy Harvester
The energy harvesters are used to scavenge the energy from sources such as mechanical vibration, solar, wind, thermal energy etc., and convert it into electrical energy. In this work, some studies on experimental analysis of a vibration based 2DOF piezoelectric energy harvester (2DOF PEH) have been carried out with a view to enhance the harvested power by adding a magnifier system to the conventional vibration based piezoelectric energy harvester (SDOF PEH) system. The piezoelectric rod of material PZT-5A is used to extract the energy by direct piezoelectric effect. A convertible model of 2DOF PEH into SDOF PEH is formulated and developed for the purpose of experimental analysis. The 2DOF PEH system comprises of the harvester system and the magnifying system. The harvester system is formed by a proof mass, piezoelectric rod and base plate. The magnifying system comprises of a magnifier mass supported by two helical compression springs in parallel. The developed model is base excited using an electrodynamic exciter .The base excitation to the magnifier system from the electrodynamic exciter introduces the mechanical strain into the piezoelectric rod and generates electricity by direct piezoelectric effect. The SDOF PEH is suitable only for the application where the source has a specific frequency of excitation to harvest the maximum amount of energy. However by adding a magnifier system, just mentioned, to SDOF PEH system, a 2DOF PEH system is developed. From the experimental analysis of developed 2DOF PEH system, it is seen that maximum power can be obtained over a wide band of operational excitation frequency. The effect of the ratio of magnifier mass to harvester mass on the harvested power is also studied.
Keywords - Piezoelectric Energy Harvester, Piezoelectric Rod, Resistive Load, Harvested Power.