振动能量收集器的最大输出电压发生在共振状态,因此其谐振频率应与环境振动频率一致。针对振动能量收集器与环境频率不匹配的问题,采用单自由度模型分析了悬臂梁一质量块结构的振动能量收集器谐振频率等性能,加工并测试了压电式的微型振动能量收集器样机,结果谐振频率的误差最大为6%。通过质量调节方法进一步将样机的谐振频率调节了10.5Hz的宽度。针对50Hz的振动环境,将谐振频率为58.7Hz的样机调节到了50.4Hz,输出电压提高了4倍。
As the output voltage of vibration energy harvester reaches peak point at resonance, the resonant frequency should he designed near ambient vibration frequency. To match the resonant frequency with ambient, sin- gle degree of freedom model was employed to analyze the vibration energy harvester with a cantilever and a tip mass. Piezoelectric micro prototypes were fabricated and tested, and the maximum error of resonant frequency was 6%. The resonant frequency of the prototype was adjusted 10.5 Hz by increasing mass. In order to approach ambient vibration frequency of 50 Hz, the resonant frequency of prototype was tuned from 58.7 Hz to 50.4 Hz, and the out- put voltage was increased 4 times.