双自由度磁悬浮式桥梁振动能量采集器数值仿真和优化

提出了一种能利用桥梁振动能量为传感器持续供电的双自由度磁悬浮振动能量采集器(TMEH),该系统的能量采集效率远高于传统单自由度磁悬浮振动能量采集器(SMEH).推导了TMEH系统的运动控制方程和机电耦合方程;建立了TMEH的多目标优化模型,提出了基于NSGA2算法的能量采集器参数优化设计方法;最后将TMEH和SMEH在简谐振动激励和桥梁随机振动激励作用下的响应特性和能量采集效率进行了对比.研究结果表明:1)通过NSGA2算法优化设计,TMEH能获得更宽的采能带宽和更高的输出功率;2)TMEH比SMEH的采能效率有明显提高.在简谐振动激励和桥梁随机振动激励作用下,TMEH的输出功率比SMEH增加了约2倍.

Numerical Simulation and Optimization of a Two-degree-of-freedom Magnetic Levitation Vibration Energy Harvester for Bridges

A two-degree-of-freedom magnetic levitation vibration energy harvester (TMEH) was designed, which can use the bridge vibration energy to provide continuous power for the sensors. The energy harvesting efficiency of the TMEH is much higher than that of the traditional single-degree-of-freedom magnetic levitation vibration energy harvester (SMEH). Firstly, the motion control equation and the electromechanical coupling equation of TMEH system were deduced. Then, the multi-objective optimization model of TMEH was established, and the design parameters were optimized by using the NSGA2 algorithm. Finally, the response characteristics of TMEH and SMEH under the harmonic excitation and normal vehicle-bridge vibration excitation were compared, respectively. The results show that: 1) After optimization by the NSGA2 method, TMEH can obtain a wider frequency band and higher output power;2) The energy harvesting efficiency of TMEH is significantly higher than that of the SMEH. Under harmonic vibration excitation and normal vehicle-bridge vibration excitation, the output power of TMEH is about two times higher than that of SMEH.