Magnetic Field Energy Harvesting in Railway

TL;DR

This paper demonstrates the feasibility of magnetic field energy harvesting from railway lines to power condition monitoring systems, showing promising laboratory and field results that could eliminate battery replacements.

Contribution

It introduces a novel application of magnetic field energy harvesting for railway monitoring, with experimental validation both in lab and real-world environments.

Findings

Power output up to 40.5 mW at 50 Hz in lab tests

Harvested 109 mJ from passing freight trains in situ

Potential to power monitoring systems indefinitely

Abstract

Magnetic field energy harvesting (MFEH) is a method by which a system can harness an ambient, alternating magnetic field in order to scavenge energy. Presented in this article is a novel application of the concept aimed at the magnetic fields surrounding the rail current in electrified railway. Due to its non-invasive nature, the approach has the potential to be widely deployed as part of low-cost trackside condition monitoring systems in order to increase lifetime and reduce maintenance requirements. In this work, the viability of MFEH in railway is substantiated experimentally -- two different configurations are assessed both in a controlled laboratory environment, as well as in situ along Norwegian railway. When placed near an emulated section of railway carrying 200 A in the laboratory, the power output of the system is up to 40.5 mW at 50 Hz and 4.15 mW at 16 2/3 Hz. In the field, the prototype system harvests 109 mJ from a single freight train passing by, rendering an estimated daily energy output of 1.14 J in a moderately-trafficked location. It is argued that the approach could indeed eliminate the need for battery replacements, and potentially increase the lifetime of an energy-efficient, battery-powered condition monitoring system indefinitely.