Power Electronic Circuits for Magnetic Energy Harvesters

Compared to many other energy harvesting schemes, harvesting energy from magnetic fields offers potential advantages for energy extraction and sensing. A magnetic energy harvester provides great flexibility for sensors and monitoring applications for condition-based monitoring of electromagnetic actuators, including vibration and thermal monitoring. A core must be managed or operated with carefully timed saturation to ensure maximum power extraction, a complex problem given the nonlinear saturation characteristics of a magnetic core [1]. This paper presents a simulator-friendly “circuit model” for a magnetic core, and uses this model to design and demonstrate several power electronic circuit solutions for harvesting energy. The circuit model has an excellent accuracy to represent the core regardless of the level of saturation. The design techniques to enhance power harvest are proposed, and verified through simulation and experiments, substantially boosting the amount of power harvest.