Inductive magnetic harvester with resonant capacitive rectifier based on synchronized switch harvesting technique

Abstract

Inductive magnetic harvesting technologies have been developing rapidly and have great potential in applications that rotate or vibrate. However, magnetic energy harvesters are often limited by their low voltage outputs, and normally, their placement are in applications that work at low frequency (typically around 100Hz). The traditional rectification with a diode bridge becomes inefficient with the resulting low harvester output voltage due to the diode forward voltage drop. This paper presents a new energy harvesting circuit, which can operate with magnetic harvesters limited by low output voltage. By adding one resonant capacitor and one bi-directional switch, the rectifier input voltage can be increased dramatically with the high voltage generated by resonance between the resonant capacitor and harvester leakage inductance. The simulation and experimental results verify the theoretical predictions.