Design of a Vibration Energy Harvester for Power Transformers Monitoring

The fault monitoring of transformers is critical for the operation of power systems. However, the traditional wireless sensor networks (WSNs) node has a short battery life, making it difficult to maintain the power supply in harsh environments such as strong electromagnetic fields and vibration noise in transformers. A MEMS AlN piezoelectric beam was designed to harvest the vibration energy at the transformer vibration frequency of 50 Hz. The resonance frequency of vibration harvester system is usually higher than 50 Hz. To reduce the resonance frequency of the MEMS harvester, a folded beam was designed and optimized using the finite element method and theoretical calculation. The results of the two methods are basically consistent. The resonance frequency, output voltage and power were analyzed, and the results show that the structure can effectively reduce the resonance frequency to 50 Hz.