This paper reports on the performances and the optimization of a 40 mm diameter water flow energy harvester based on an axial turbine (horizontal axis propeller) coupled to a customized permanent magnet generator. To the best of our knowledge, this work is one of the first comprehensive studies in the low dimensional and flow velocities ranges. The parameters of the propeller have been empirically optimized ( D l =1, B=4 blades) by the means of experiments in a test-bench pipe at various flow rates from 1 to 9 m 3 h −1 . The best propeller design has been selected for its performances in terms of electrical power and pressure drop. A customized permanent magnet converter with ferromagnetic elements has been modeled, optimized with finite elements simulations and fabricated.

Magnetodynamic wireless power transfer (WPT), also known as electrodynamic wireless power transfer, is a low-frequency WPT technology based on an electromechanical receiver comprising a permanent magnet moving in a coil. Because of the low-frequency field, this technology is safe around humans and enables transfer through conductive media. In this paper, we focus on the design and the optimization of the power receiver with advanced modelling methods. Two operating modes, namely a continuously rotating mode and a resonant mode, targeting high-power-density and mid-range power transfer respectively, are investigated and compared to previous versions. The fabricated 25-cm 3 receiver presents substantial improvements in terms of transferred power (3.3W) and power density (x7) compared to previous receivers in the same conditions of fields.

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This paper reports on an innovative electromagnetic energy harvester for autonomous switches relying on a rotating magnet driven by magnetic launchers, and combined with a ferromagnetic circuit and a coil to turn the variation of magnetic flux induced by the rotating magnet into electricity. The device is able to operate on forward and backward translation movements. The energy harvester has been modeled, optimized, manufactured, characterized and integrated into a mechanical actuation system to form a complete autonomous switch that will be commercially available. The experimental output energy reaches 1.235 mJ (350 µJ cm−3) which is among the highest output energies and energy densities reached on autonomous switches in the state of the art. The electromechanical conversion efficiency is 56%, which is excellent for an energy harvester, and obtained thanks to the topology chosen for the electromagnetic converter. The energy harvester is finally connected to a diode-bridge-capacitor circuit to supply the RF emission of the commands with a Zigbee Green Power® transmitter.

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