A direct AC-DC and DC-DC cross-source energy harvesting circuit with analog iterating-based MPPT technique with 72.5% conversion efficiency and 94.6% tracking efficiency

The proposed cross-source energy (CSE) harvesting circuit can accept universal energy sources, including AC and DC sources. The buck-boost conversion of CSE harvesting circuit automatically converts AC or DC input into DC output without being limited by universal input voltage range. CSE harvesting circuit provides dual outputs, a regulated output and a battery charging output, to optimally arrange harvest energy with 72.5% of power efficiency. A backup converter is designed to cooperate with CSE harvesting circuit to guarantee voltage stability of the regulated output. The proposed analog iterating-based (AIB) maximum power point tracking (MPPT) technique achieves 94.6% tracking efficiency without complex data calculation and storage compared to previous techniques.