基于电磁感应和压电效应复合的变压器振动能量收集研究

How to supply energy to massive sensors is an urgent problem to be solved in the construction of power Internet of things. Energy harvest technology provides a feasible solution to this problem. Transformer generates significant vibration energy with a main frequency at 100 Hz under action of the power frequency magnetic field. However，an effective harvest mode has been lacking. In this paper，a vibration energy harvester with electromagnetic induction and piezoelectric effect is designed and made by using the resonant structure of cantilever beam. The frequency response characteristics of the energy collector are tested. The resonant frequency of the element is 100 Hz，and the 3 dB bandwidths of the piezoelectric part and the electromagnetic part are 4.1 Hz and 2.0 Hz，respectively. Under the vibration condition of 100 Hz/5 m·s^-2，the open-circuit voltages of the piezoelectric part and the electromagnetic part are 44.98 V and 6.85 V respectively. Under the same conditions，the maximum output power is 28.17 mW and harvester can charge a 100 mF capacitor to 3.81 V in 300 s. Under the conditions of laboratory simulation and transformer field test，the application prospect of the energy harvester is tested. The energy harvester can harvest the vibration energy of the transformer shell，charge the capacitor and drive the sensor.