A Noval Electromagnetic Generator with Spring Amplification Structure for Vibration Energy Harvesting of Power Equipment

The vibration with frequency of 100Hz is widely distributed in the power equipment, and this may provide a new method to supply energy for sensors by vibration energy harvesting. However, the vibration acceleration in power equipment is usually small. Meanwhile, the energy harvesting efficiency of existing vibration energy harvesters is low under small acceleration, resulting in limited practical application. Therefore, the vibration law of the two-degree-of-freedom system is studied, and an elastic amplification structure is proposed based on the spring and cantilever structure. Then, based on the electromagnetic generator (EMG), an electromagnetic generator with spring amplifier (S-EMG) was fabricated. Comparing with EMG, S-EMG could provide output voltage and power of 11.45V and 34.88mW (matched resistance is 100Ω) at an acceleration of 5m·s-2, which is 136% higher than the output power of general EMG. The 100mF capacitor could be charged to 3.74V within 300s, which is 44% higher than EMG. Besides, S-EMG can continuously drive a commercial wireless temperature/humidity sensor to send the signal to a mobile phone via Bluetooth.