基于等效电路法的变三角截面驰振压电能量收集研究

随着能源危机的逐渐加剧，人们对压电俘能器研究的投入也与日俱增，目前常见的研究压电俘能器的模拟方法只能研究其接入简单的单一电阻负载电路时的性能，且不能解决压电俘能器的高强度直流电路耦合问题。因此，本文借助二阶范德波尔控制方程将压电俘能器的主要部件等效为电子元件，进而基于等效电路法建立了与变三角截面驰振压电振动俘能器相对应的等效电路模型。借助风洞实验验证了所建立的等效电路模型的准确性。采用该模型研究了外接电路，钝体顶角，外接电阻和来流速度对变三角截面驰振压电俘能器输出电压，输出功率和响应位移的影响，结果表明，随着电阻的增大，输出电压逐渐增大且增长率逐渐减小。交直流电路的最佳负载分别为1.05 MΩ和1.4 MΩ，当风速为7.03 m/s，钝体顶角为90°时，交直流电路输出电压和输出功率的峰值分别为41.34 V，0.974 mW和50.8 V，0.616 mW。随着钝体顶角的增大，输出电压，输出功率和响应位移均逐渐增大且增大的速度逐渐减小。等效电路模型可以高效，准确地对不同结构参数下和外界电路下的压电振动俘能器的输出功率，输出电压，响应位移及其影响因素进行研究，所提出的等效电路模型于加快对压电振动俘能器的研究与推广应用具有一定意义。

Research on Piezoelectric Energy Harvesting of Variable Triangular Cross-sections Based on Equivalent Circuit Method

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.