基于MSMA振动能量采集的传感器节点供电系统

Power Supply System of Sensor Node Based on MSMA Vibration Energy Collection

利用磁控形状记忆合金(MSMA)将环境中机械振动能量转变成电能并为传感器节点供电正逐渐被国内外科研人员重视。基于MSMA振动能量采集器的输出特性,设计了一种传感器节点供电系统,可在低至20m V的超低输入电压下运行。上述系统由采集器输出和主电池两个供电部分组成,可实现无缝切换,并优先启动环境振动源。当采集能量满足负载要求时,仅依靠采集器输出来供电,且此时从主电池吸收的静态电流低至80n A。当采集器输出功率不足时则由主电池供电,采集器输出电能会储存在电容器中,且系统提取主电池低至6μA的电流便可维持稳定运行。仿真结果表明,当采集器输出电压幅值和频率发生改变时,系统可保持稳定的有效输出。且上述方案低功耗、高效率,可大大延长系统供电寿命。

It is receiving higher emphasis from domestic and foreign researchers that. mechanical vibration energy in environment is transformed into electric energy through magnetic shape memory alloy （MSMA） , which then acts as the supplies power to sensor node. Based on the output characteristic of MSMA vibration energy collector, a sensor node power supply solution is proposed in the paper, which can operate in the ultralow input voltage even at 20mV. Composed of two power supply parts of collector output and main battery, this solution can realize seamless switching and give priority to the use of vibration source. When the collected energy meets the load requirement, it operates merely depending on collector output, and the quiescent current absorbed from main battery at this moment is as low as 80nA. On the contrary, when collected output power is insufficient, it operates merely depending on the main battery, and the collector output electric energy will be stored in capacitor, where the extraction of current as low as 6 μA in main battery can maintain system operation. The simulation result shows that, the system can maintain stable effective output even if the output voltage amplitude and frequency of collector change. By virtue of low energy consumption and high efficiency, this solution will greatly extend system power supply.