Innovative power conditioning and interfacing circuitry for various energy harvesting devices

Abstract

This research work focuses on the design, implementation, fabrication and characterisation of a novel power conditioning integrated circuit proposed for capturing maximal energy from a wide range of energy devices. The proposed power conditioning circuit has a wide input voltage range and power range and employs a maximum power point tracking circuit to operate the energy harvesting device at maximum power at any operating condition. A direct AC/DC-to-DC converter makes this power conditioning circuit compatible with harvesters generating both AC or DC output voltages without the need of external rectification. Energy storage is provided by means of a high storage capacitor which reduces the down time of the load and stores any excess power being generated by the energy harvester. The final stage of the conditioning circuit is a hysteretic controlled buck converter which generates an adjustable, clean, and constant output voltage as required by the load. Both circuit stages were fabricated while requiring a minimum number of external components. In particular, the work undertaken and explained in this dissertation can be classified into two main parts. The first part focuses on the design, implementation, simulation, fabrication and characterisation of a novel direct AC/DC-to-DC converter with MPPT function. The second part focuses on the design, implementation, simulation, fabrication and characterisation of a novel hysteretic controlled buck converter integrated with on-chip bootstrapping circuit.