Energy Harvesting Technologies

This report is for the energy harvesting activities in the project, 2020~2021. During 2020~2021, a multi-source Energy harvester for low power applications have been studied explicitly. Solar and wind energy are extracted to supply a wireless sensor and charge a single-cell Li-ion battery. The maximum power point tracking (MPPT) technique implemented using DC-DC Converters for high-efficiency harvesting. Additionally, the proposed CC/CV battery charging algorithm was established based on the renewable source's maximum power availability. At the same time, the Vibration energy harvested using Piezoelectric strings is stored temporarily in a capacitor then discharged into the DC bus or directly to the load through a DC-DC converter to provide more stability to the system responses. Also, multiple control techniques have been developed, such as a linear controller (PI), a combination of linear and non-linear controllers (PI and Hysteresis switching control), and Fuzzy logic controller (FLC). Then a comparison between each controller was observed in both simulation and experimentally for MPPT and CC/CV battery charging. The multi-source energy harvester was implemented on an SMD PCB circuit prototype. Similarly, the Hysteresis switching control (HSC) was implemented as a mixed-signal design using SMD PCB.