Modeling, simulation and analysis of piezoelectric energy harvester for wireless sensors

This paper details the modeling, simulation and experimental analysis of piezoelectric energy harvester designed for low power devices like wireless sensor network nodes. The ultimate goal of this work is to harvest the energy available in the vibration environments viz. industrial machineries, ducts, automobiles systems, road infrastructures, railway tracks etc. Efficient extraction of energy from the vibration source is essential and can be achieved by adopting the principles of maximum power transfer and impedance matching. Impedance matching reduces losses in the harvested energy between the systems being coupled, mechanical to electrical to rectifier to DC-DC converter to the load. The selection of suitable DC-DC converter topology and components for converter enables optimal harvesting of energy from the piezo transducer. The piezoelectric energy harvester system components viz. piezo element, rectifier, dc-dc converter, load were modeled and simulated using SPICE. This modeling enabled to find the optimal energy profile (number of piezo devices and source of vibration energy) of the harvester and optimal duty cycle for the wireless sensor node based on the available energy. The modeling and simulation results have been compared and analyzed with the experimental results. It has been validated from the results that, it is feasible to power wireless sensor device for a specific duty cycle with consistent source of vibration energy from two piezo elements.