采用复合磁电换能器的宽带振动能量采集器

A new magnetoelectric broadband vibration energy harvester

采用磁致伸缩/压电层合磁电换能器设计了一种新型的宽带振动能量采集器,采集器由多个悬臂梁、磁电换能器和永磁体组成,将磁电换能器和提供磁场的永磁铁分别与悬臂梁构成具有不同固有频率的弹性结构,从而响应不同频率的机械振动。推导了换能器和永磁体组间磁力作用下能量采集器的动力学方程及其电输出模型;借助磁场分析软件Ansoft's Maxwell研究了影响能量采集器的频率特性及电能输出的因素,为获得最优性能的能量采集器提供设计依据。根据分析设计了振动能量采集装置并进行了实验,实验结果表明:在振动加速度为0.2 g(g=9.8 ms-2)时,当两悬臂梁间频率差为3.6 Hz时,振动能量采集器响应频带宽度从单梁结构的0.8 Hz增加到双梁结构的5.0 Hz,负载电阻为1 900Ω时,其上的功率达到最大0.22 mW。

In this paper, a new broadband vibration energy harvester using magnetoelectric （ME） transducer is pro- posed. The harvester consists of two cantilever beams, a magnetic circuit, and a ME transducer. The two cantilever beams are initially designed to have different natural frequencies for responding different external vibration frequencies. The vibration equation and the electrical-output model of the harvester are developed. In order to achieve the optimal vibration energy harvesting performances, the effects of the structure parameters on the electrical-output and the bandwidth of the harvester are analyzed by Ansoft＇s Maxwell. The experimental results show that, when the frequency difference of the two beams is 3.6 Hz, the harvester has bandwidth of 5.0 Hz, and the maximum output power of 0.22 mW across a 1 900Ω resistor at accelerations of 0.2 g （with g = 9.8 ms^-2 ）.