Research on vibration energy harvesting technology of power equipment based on alternating magnet array

Vibration with a frequency of 100 Hz is widely distributed in the power equipment, and it can provide a new way to supply energy for sensors by vibration energy harvesting. The vibration energy harvesting method based on electromagnetic induction principle was studied through the arrayed structure of magnets and coils. Static magnetic field models were established for four magnet array structures and it was found that the alternating magnet array has the largest magnetic flux and magnetic flux gradient. Based on the alternating magnet array, prototypes of energy harvester with vertical and parallel movement mode were proposed. Through structural parameter optimisation analysis, two different energy harvesters were fabricated and it was found that the energy harvester with a parallel movement mode has better output performances. The energy harvester could provide output voltage/current and power of 8.35 V/17.39 mA and 15.13 mW (matched resistance is 200 Ω) at an acceleration of 5 m·s⁻². The 100 mF capacitor could be charged to 2.72 V within 300 s, and the final voltage of the capacitor is greater than 3 V, which could sustainably drive commercial wireless temperature/humidity sensors.