Multi-directional electromagnetic vibration energy harvester using circular Halbach array

Abstract

In this paper, a multi-directional electromagnetic vibration energy harvester (EVEH) using the circular Halbach array (HA) is presented based on the Faraday’s law of electromagnetic induction. The circular HA is a specific arrangement of permanent magnets which could concentrate the magnetic field inside the circular array by a certain rule, while reduce the magnetic field outside the circular array to almost zero at the same time. The HA could break through the limitation of the related published vibration energy harvesters that could work in only one single direction. Thus, it could optimize the collecting efficiency. The experimental results show that the presented harvester could generate considerable electric output power in all vibrating directions. An optimal output power is 9.32 mW at a resonant frequency of 15.40 Hz with an acceleration of 0.5 g (with g=9.8 m/s2) across a 700-turn coil in the vibrating direction of 90°, which is 1.53 times than the minimum optimal one in the direction of 45°. The EVEH using the circular HA could work in all directions and generate considerable electric output power, which validates the feasibility of the EVEH that works in all directions and is beneficial for improving the practical application.

Electromagnetic Vibrational Energy Harvesters: A Review

“…Qiu et al [ 55 ] experimented using circular Halbach arrays and a moving coil, as shown in Figure 6 . They researched the increase in efficiency by using Halbach arrays, which could operate in multiple directions.…”

A hybrid wave vibration energy harvester with electromagnetic double-speed and piezoelectric up-frequency driven by a rotating ball

“…However, the utilization of the magnetic circuit is low, resulting in low energy harvesting efficiency. Qiu et al [21] carried out experiments using circular Haarbach arrays and moving coils, studying the application of a Haarbach array to improve magnetic flux utilization efficiency, which can operate in multiple directions. Under excitation at 15.4 Hz and 0.5 g, the energy harvester could generate 7.29 mW of power.…”

Characteristic Analysis, Simulation, and Experimental Comparison of Two Kinds of Circular Magnet Array in Energy Harvesting

“…In addition, some in-plane Halbach arrays [11][12][13] and cylindrical Halbach arrays [14][15][16][17][18] have been presented and utilized. Qiu [19] and Liu [20,21] designed an electromagnetic energy harvester employing a Halbach array and a coil. The coil, which is attached to the end of the cantilever beam, vibrates and results in the generation of induced voltage.…”