High-performance magneto-mechano-electric generator through optimization of magnetic flux concentration

Abstract

A magneto-mechano-electric (MME) generator can convert a stray magnetic field around electrical power transmission cables into electrical energy. The output power of the MME generator can be significantly enhanced when the magnetic flux density is focused on the magnetostrictive constituents and proof permanent magnet mass. In this study, magnetic flux concentrators (MFCs) fabricated from three types of soft magnetic materials, i.e., nickel, stainless steel grade 430, and high-purity iron (Fe), were deployed around an MME generator, and the effect of magnetic properties, especially the magnetic permeability of MFC materials, on the performance of MME generators was investigated. Finite element analysis and experimental verification confirmed that MFCs with higher magnetic permeability can focus more magnetic flux to the MME generator, which can induce more harvested electrical energy. A prototype battery-less smart clock powered by an MME generator with an MFC was designed and fabricated. Under real practical conditions, a six-fold enhancement in the output power was observed in the MME generator with pure-Fe MFC as compared to that without MFC. Therefore, it was established that MME generators with pure-Fe MFC demonstrated excellent potential for application as an autonomous onboard power supply for smart things-compatible modules.