SPICE modelling and analysis of hybrid energy harvester combiner topologies

Abstract

Harvesting energy from multiple hybrid sources and efficiently combining the harvested energies is critical for enabling self-powered devices. Designing an efficient energy combiner is a technical challenge and is non-trivial. Various factors viz. kinds of sources, harvestable energy level and range from the sources, electrical characteristics of sources (low current and high voltage, high current and low voltage, capacitive, inductive etc.), impedance matching (resistive, resistive-reactive, modulus, complex conjugate etc.) of sources, sources scheduling algorithms for combiner, sources switching and control/trigger circuit losses, power conversion and management etc. influence the overall energy combiner’s efficiency. Considering that, this article presents a SPICE modelling and simulation framework for analyzing hybrid energy harvester combiner topologies such as Inductor sharing, voltage level detection and powerORing for its power and energy flow characteristics, regulation, and energy combining efficiency. Such analysis through simulation enables arriving efficient combiner architecture for the chosen harvestable resources, source models, power management circuits and schemes etc. Based on a case study with three different kinds of sources, it has been observed that the voltage level detection technique with DC-DC converters results in the highest efficiency as compared with the other two topologies for such a scenario.