一种非线性宽频压电能量收集系统的动力学特性分析

Dynamic characteristics of a nonlinear wideband energy harvester based on piezoelectric material

提出了一种基于同步开关电路的非线性宽频压电能量收集器,并利用高阶谐波平衡法对能量收集系统的频域响应、能量输出功率及其影响因素等内容展开了理论研究,同时利用Hill法对系统的稳定性进行了分析。研究结果表明在基于同步开关电路的能量收集系统中引入副梁,可以大大拓宽能量收集系统工作频带;适当减小同步开关电路的电容比,虽然会降低能量收集系统在共振峰附近的能量收集能力,但可以拓宽系统的工作带宽;能量收集系统的工作带宽随副梁与质量块间初始间隙的减小以及副梁刚度的增大而拓宽,可根据振动能量源频率带宽及能量的频域分布规律,对系统关键参数进行匹配设计,以获得更好的能量收集效果。

A nonlinear wideband energy harvester based on the synchronized switch circuit is proposed.The forced response of the nonlinear energy harvesting system in frequency domain is obtained by the multi-harmonic balance method(MHBM),and stability of the system is analyzed by the Hill’s method.The results show that,although the highest performance of energy harvesting will be reduced with decreasing of the capacitance ratio of the SSHNC,the effective working bandwidth will be widened.With the increasing of the stiffness of secondary beams and the decreasing of the initial gap between secondary beams and the main beam,the effective working bandwidth of the energy harvesting system will be greatly broadened,but the output power near the formant will be reduced.The key parameters of the system can be matched and designed according to the frequency bandwidth and frequency distribution of the vibration energy source,so as to obtain better energy harvesting performance.