Hybrid Low Frequency Electromagnetic Field and Solar Energy Harvesting Architecture for Self-Powered Wireless Sensor System

摘要

The development of micro-energy harvesting technology provides a new energy solution for wireless sensor nodes (WSNs). Due to the intermittent power supplied by single environmental energy source, this paper proposes a hybrid energy harvesting architecture that harvest magnetic field (50-60 Hz) and solar energy simultaneously, which aims to provide a sustainable power supply for WSNs. Firstly, the design of free-standing 'I-shaped' magnetic field transducer is introduced, which can harvest 0.17-0.46 mW underneath 700 A power transmission line. A further design of a rectifier and matching circuit is conducted and the maximum power point (MPP) of the hybrid energy harvesting circuit is about 60% of the open circuit voltage and the conversion efficiency reaches 61.68%. The experimental results show that the hybrid solar and 'I-shaped' transducer can accomplish 'cold start' operation of the power management unit (PMU) under magnetic flux density of 4.5 μT and light intensity of 200 lx, which will also provide a promising supply of energy for WSNs.