Sanfelice Angelo, Costanzo Luigi, Lo Schiavo Alessandro, Sarracino Alessandro, Vitelli Massimo
Department of Mathematics and Physics, University of Campania "Luigi Vanvitelli", Viale Lincoln 5, 81100 Caserta, Italy.
Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy.
Entropy (Basel). 2024 Dec 14;26(12):1097. doi: 10.3390/e26121097.
We present an experimental and numerical study of a piezoelectric energy harvester driven by broadband vibrations. This device can extract power from random fluctuations and can be described by a stochastic model, based on an underdamped Langevin equation with white noise, which mimics the dynamics of the piezoelectric material. A crucial point in the modelisation is represented by the appropriate description of the coupled load circuit that is necessary to harvest electrical energy. We consider a linear load (resistance) and a nonlinear load (diode bridge rectifier connected to the parallel of a capacitance and a load resistance), and focus on the characteristic curve of the extracted power as a function of the load resistance, in order to estimate the optimal values of the parameters that maximise the collected energy. In both cases, we find good agreement between the numerical simulations of the theoretical model and the results obtained in experiments. In particular, we observe a non-monotonic behaviour of the characteristic curve which signals the presence of an optimal value for the load resistance at which the extracted power is maximised. We also address a more theoretical issue, related to the inference of the non-equilibrium features of the system from data: we show that the analysis of high-order correlation functions of the relevant variables, when in the presence of nonlinearities, can represent a simple and effective tool to check the irreversible dynamics.
我们展示了一项关于由宽带振动驱动的压电能量采集器的实验和数值研究。该装置可以从随机波动中提取能量，并且可以用一个基于带有白噪声的欠阻尼朗之万方程的随机模型来描述，该模型模拟了压电材料的动力学。建模中的一个关键点是对用于采集电能的耦合负载电路进行恰当描述。我们考虑了线性负载（电阻）和非线性负载（连接到电容和负载电阻并联的二极管桥式整流器），并关注提取功率作为负载电阻函数的特性曲线，以便估计使收集能量最大化的参数的最佳值。在这两种情况下，我们发现理论模型的数值模拟与实验结果之间有很好的一致性。特别是，我们观察到特性曲线的非单调行为，这表明存在一个使提取功率最大化的负载电阻最佳值。我们还探讨了一个更具理论性的问题，即从数据推断系统的非平衡特征：我们表明，当存在非线性时，对相关变量的高阶相关函数进行分析可以成为检验不可逆动力学的一种简单而有效的工具。
