Digitally-controlled H-bridge DC-DC converter for micropower PV energy harvesting system

• Main Authors: Bui, Anh Khoa, Xiao, Zhekai, Siek, Liter
• Other Authors: School of Electrical and Electronic Engineering
• Format: Conference or Workshop Item
• Language: English
• Published: 2021
• Subjects: Engineering::Electrical and electronic engineering; Digitally-controlled H-bridge DC-DC Converter; Micropower PV Energy Harvesting System; Micropower Photovoltaic Harvesting System; Internet of Thing; Rechargeable Battery; Heavy-load Condition; Perturb-and-Observe Maximum Power Point Tracker; MPPT; PV Harvester; Pulse-Width Modulation; Pulse-Frequency Modulation
• Online Access: https://hdl.handle.net/10356/152171
• Institution: Nanyang Technological University

This paper presents a micro-power photovoltaic (PV) harvesting system. A H-bridge configuration DC-DC converter is designed to harvest PV energy and deliver energy to applications of Internet of Thing (IOT). The main converter consists of a single inductor with two inputs and two outputs. It regulates a constant 1V output voltage for several applications such as sensors and signal transmitters. The surplus energy is stored in a rechargeable battery. The battery also serves as a secondary input source to provide energy to the output load in heavy-load condition. Due to the limited energy of the system, the power consumption of the power system is optimized by several techniques. A perturb-and-observe maximum power point tracker (MPPT) is implemented to maximize the power extracted from the PV harvester. Pulse-width modulation (PWM) and pulse-frequency modulation (PFM) are used to regulate the output voltage. The controller is designed mainly in digital and free of power-hungry circuits. The proposed converter occupies an area of 1.44mm2. The estimated peak power efficiency is 84% while driving 3-10μA load current.