A study of a multi-pole magnetic generator for low-frequency vibrational energy harvesting

This paper theoretically and experimentally investigates voltage enhancement effects using a multi-pole magnet array in a magnetic energy harvester. The use of multiple magnetic poles is shown to increase the frequency and amplitude of the output voltage, addressing one of the primary disadvantages of magnetic transduction schemes, especially for low-frequency vibrations. Experimental results from a four-pole prototype demonstrate a three times improvement in rms voltage as compared to conventional single-magnet designs along with frequency up-conversion where the frequency content of the electrical output occurs at harmonics of the mechanical excitation frequency. The magnetic multi-pole approach is also further studied through simulation-based parametric analysis.