Power Conditioning for Energy Harvesting-Case Studies and Commercial Products

This chapter discusses several case studies of prototype harvester systems which feature nontrivial power processing interfaces, the techniques utilized and solutions. Two examples of interface circuits for electromagnetic harvesters are presented, one which performs real-time maximum power point tracking, rectification, and voltage boost and one which is able to frequency-tune the harvester, widening the bandwidth. An implementation of a single-supply pre-biasing circuit for piezoelectric harvesters is described, with particular emphasis on the design of the switches and low-power timing control. A simple yet practical demonstration of an interface circuit for an electrostatic electret-based harvester is also presented. Then, moving away from kinetic harvesters, a thermal harvester system in which a low-power rectifier and interface circuit for use on an aircraft application is presented. Finally, some commercial power electronic interface integrated circuits are discussed. The functionality of the integrated circuits allows power density to be increased.