闭合磁路电磁式低频振动能量收集装置

为了提高能量转换效率，提出一种新型电磁式低频振动能量收集装置。该装置形成闭合磁路，大幅度提高了能量获取能力；同时利用对称布置的4片磁轭平衡了振子所受磁力，大幅降低振子运动阻力。通过Ansoft Maxwell静态仿真，分析了气隙宽度、相对磁导率、铁芯半径和衔铁齿厚度对线圈最大磁感应强度的影响，并据此优化了参数。另一方面，利用动态仿真得出1 Hz的振动频率下，可产生1.5 V感应电动势，最大有效功率可达12.02 mW，表明装置可以用于为低功耗的无线传感网络节点供电。

Improved Electromagnetic Energy Harvesting from Low-Frequency Vibrations by Closed Magnetic Circuit

In order to improve efficiency of energy conversion,a novel electromagnetic low-frequency vibration en?ergy harvesting device is proposed. This device is designed including closed magnetic circuits which are significant to improve the ability of energy harvesting. Meanwhile,by the symmetrical distribution design of four dentate yokes, the magnetic force between the armature and yokes are balanced so that the motion resistance of the vibrator could be reduced markedly. By using Ansoft Maxwell,the static simulations expose how the maximum magnetic flux densi?ty of the coil is influenced by the width of air gaps,the relative permeability of ferromagnetic material,the radius of the iron cores and the thickness of the armatures respectively. On the other hand,the dynamic simulations show that the device can supply an induction electromotive force at 1.5 V and a maximum effective power at 12.02 mW when the frequency of vibration is 1 Hz. It demonstrates that the new low-frequency vibration energy harvesting device is able to power for many low consumed power wireless sensor network nodes.