具有弹性放大器的双稳态压电俘能器建模及参数影响分析

利用广义Hamilton变分原理,建立了具有弹性放大器的双稳态压电俘能系统BPH+EM的动力学方程。考虑谐波激励,采用调和平衡法获得了BPH+EM系统的位移、输出电压和功率的解析解。利用求得的解析解,讨论了BPH+EM系统扩大能量俘获的频率范围和提高能量俘获效率的机理,研究了弹性放大器的刚度质量比对BPH+EM系统的动力性能影响规律。当弹性放大器的刚度质量比趋于无限大时,具有弹性放大器的双稳态压电俘能系统退化为双稳态压电俘能系统BPH。弹性放大器的刚度质量比趋于0但不等于0时,BPH+EM的俘能效率低于BPH。结果表明,在合适的刚度质量比范围内,BPH+EM的俘能效率显著优于BPH。研究结果为BPH+EM系统的优化设计提供了理论指导。

Modeling and parameter influence analysis of bistable piezoelectric energy harvester with an elastic magnifier

The dynamic equation of bistable piezoelectric energy harvesters with an elastic amplifier (BPH+EM) is established using the generalized Hamilton variational principle.Considering harmonic excitation,the analytical solutions of displacement,output voltage and power of the proposed model are obtained by harmonic balance method.Using the proposed analytical solution,this paper discusses how BPH+EM system enlarges the frequency range of the energy capture and improves the efficiency of energy capture,and studies the influence of the stiffness-mass ratio of the elastic amplifier on the dynamic performance of BPH+EM system.It has proved that BPH+EM degenerate into bistable piezoelectric energy harvesters (BPH) when the stiffness of the elastic amplifier tends to be infinite,and that the harvesting energy efficiency of BPH+EM is lower than that of BPH when the stiffness of the elastic amplifier approaches zero but is not equal to zero.The results show that the energy harvesting efficiency of BPH+EM is significantly higher than BPH in the case of the appropriate stiffness to mass ratio.The research results provide theoretical guidance for the optimal design of BPH+EM.