Optimal load resistance of a randomly excited nonlinear electromagnetic energy harvester with Coulomb friction
Optimal load resistance of a randomly excited nonlinear electromagnetic energy harvester with Coulomb friction
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DOI：
10.1088/0964-1726/23/9/095001
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发表时间：
2014-09
影响因子：
4.1
通讯作者：
Y. Tian;Y. Wang;X. Jin;Z. L. Huang
中科院分区：
文献类型：
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作者：
Y. Tian;Y. Wang;X. Jin;Z. L. Huang
本文考虑了一种直接为负载电阻供电的非线性电磁能量采集器。非线性包括立方刚度和不可避免的库仑摩擦，基础激励仅限于高斯白色噪声。直接从耦合方程出发，通过广义谐波变换和等效非线性化技术，提出了一种计算随机响应和平均输出功率的新方法。建立了负载电阻与内部电阻的最佳比率以及相关的最佳平均输出功率对线圈内部电阻的依赖关系。阻抗匹配的原理只有在内阻为无穷大时才是正确的，当内阻接近零时，最优平均输出功率接近一个上限。研究了库仑摩擦对最优阻力比和最优平均输出功率的影响。证明了库仑摩擦力虽然显著降低了最优平均输出功率，但几乎不改变最优阻力比。
A nonlinear electromagnetic energy harvester directly powering a load resistance is considered in this manuscript. The nonlinearity includes the cubic stiffness and the unavoidable Coulomb friction, and the base excitation is confined to Gaussian white noise. Directly starting from the coupled equations, a novel procedure to evaluate the random responses and the mean output power is developed through the generalized harmonic transformation and the equivalent non-linearization technique. The dependence of the optimal ratio of the load resistance to the internal resistance and the associated optimal mean output power on the internal resistance of the coil is established. The principle of impedance matching is correct only when the internal resistance is infinity, and the optimal mean output power approaches an upper limit as the internal resistance is close to zero. The influence of the Coulomb friction on the optimal resistance ratio and the optimal mean output power is also investigated. It is proved that the Coulomb friction almost does not change the optimal resistance ratio although it prominently reduces the optimal mean output power.