Analysis Model for Magnetic Energy Harvesters

• Published in: IEEE transactions on power electronics Vol. 30; no. 8; pp. 4302 - 4311
• Main Authors: Jinyeong Moon, Leeb, Steven B.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Circuits; Current transformers; Design optimization; Detection; Electrical equipment; Electronics; Experiments; Harvesters; IP networks; Magnetic fields; Magnetism; Mathematical model; Optimization; Saturation magnetization; Sensors; Solar energy; Transformer cores; Transformers; saturation; harvest; Energy; inductor; transfer window; nonideal; transformer; magnetic; power; nonlinear
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2014.2357448

Energy harvesting offers an important design option for creating sensing and control elements without a requirement for custom wiring or batteries. An exciting possibility creates a "self-powered" sensor node with an integrated energy harvester that can extract power from the magnetic fields around a power line to a load, in the manner of a current transformer. However, this "current transformer" provides not just current sensing, but also power for a sensor package, all without ohmic contact. This paper provides a technique for design optimization for maximizing power harvest, revealing a critical result: For any given core in any particular application, power harvest is maximized when the core is permitted to saturate at an opportune time in the line cycle. Circuits for optimizing this power transfer window and experimental results supporting the analysis are presented in this paper.