Abstract：With the gradual increase of the energy crisis, more research on piezoelectric energy harvester research is conducted. The common simulation methods which are used to study piezoelectric energy harvester can only study the performance when it is connected to a simple single-resistive load circuit. The coupling problem of high-intensity DC circuits cannot be solved. In order to overcome these problems. First, the main components of the piezoelectric energy harvester are equivalent to electronic components by the second-order van der Pol's governing equation. And then the equivalent circuit models corresponding piezoelectric energy harvesters with different triangular cross-sections are established, based on the equivalent circuit method, Next the correction of the established equivalent circuit model is verified by wind tunnel experiments. Finally, the influence of external circuit interface, the apex angle of bluff body, external resistances and inflow velocity on the output voltage, output power and response displacement of the galloping piezoelectric energy harvester are analyzed by the model. It is found that with the increase of external resistances, the output voltage gradually increases and the growth rate gradually decreases. The optimum load resistance of the AC-DC circuit is 1.05 MΩ and 1.4 MΩ respectively. When the wind speed is 7.03 m/s and the apex angle of bluff body is 90°, the peak output voltage and output power of the AC-DC circuit are 41.34 V ,0.974 mW, and 50.8 V, 0.616 mW respectively. As he apex angle of bluff body increases, the output voltage, output power and response displacement gradually increase and the increasing speed gradually decreases. The equivalent circuit model can efficiently and accurately study the output power, output voltage, response displacement and its influencing factors of piezoelectric vibration harvester with different structural parameters and external circuits interfaces. The proposed equivalent circuit model has certain significance in accelerating the research and application of piezoelectric vibration energy harvester.
2019, Vol. 40 
