Characterization of a variable reluctance harvester

Abstract

Abstract. In our last year's PowerMEMS contribution we presented a proof-of-concept of a variable reluctance harvester for the application in a railroad surveillance system. It was shown that intermittently closing a magnetic circuit could supply power output in the range of mW's. The test setup used showed unwanted energy pickup from the electro motor used. In this paper we present thorough measurements of the reluctance circuit with a compressed air motor to exclude the effects of the above mentioned magnetic stray fields. The effects of eddy currents and moment of inertia on the output power, the optimal coil position on the stators, and effects of different magnetic field strengths are studied. The gap width is set to a fixed value of 14 mm, representing a realistic scenario.

Review and Analysis of Magnetic Energy Harvesters: A Case Study for Vehicular Applications

“…They usually convert the commonly found rotary kinetic motion in a magnetic field. A vast area of research is focused on the implementation of VREHs to optimize the output power [108][109]. In [110], the authors proposed and embedded VREH to power an integrated WSN in the railways.…”

Mechanical Energy Harvesting Taxonomy for Industrial Environments: Application to the Railway Industry

“…• Variable reluctance: Depending on which structure creates the variation of reluctance, the harvester can be placed on both the rotating and the static part [106]. Variable reluctance harvesters applied to rotary locations take advantage of existent structures [54] or structures designed to optimize the variation of reluctance [107], [108] and thus the quantity of mechanical energy converted into electricity.…”

“…With regards to frequency and acceleration, variable reluctance harvesters have the same operating range than electromagnetic ones, up to 10's kHz and 50G respectively. Analyzing the number of publications in the field of variable reluctance applied to rotational motion [33], [54], [106]- [108], it can be concluded that it is an interesting research gap to be addressed. • Magnetostrictive: This technology has not been evaluated yet for rotational motion.…”