针对振动能量采集器的输出功率过低不足以直接驱动无线传感器的问题,设计了振动自供能无线传感器的电源管理电路,根据调谐和阻抗变换原理对能量采集器进行了阻抗匹配,以最大功率对储能超级电容进行充电,对能量存储和电源管理电路的充放电特性进行了理论分析和实验验证。结果表明,该电路大幅度提高了采集器的输出功率和对储能超级电容充电的效率,当0.47F超级电容电压达到0.6V时,能量瞬间释放电路控制超级电容瞬间放电,成功驱动最大功耗为75mW的无线传感器工作。
A power management circuit for a vibration energy self-powered wireless sensor is designed in this paper to solve the problem of the low output power of the vibration energy harvester which leads to the failure of driving a wireless sensor directly. Based on the principles of tuning and impedance conversion, the impedance match of the energy harvester is realized; the storage supercapacitor is charged with maximum power; and the charging and discharging characteristics are researched theoretically and experimentally. The results show that the output power of the vibration energy harvester and the efficiency of its charging to the super capacitor are significantly improved. When the voltage across the 0.47F supereapacitor has been charged to 0.6 V, the supercapacitor will discharge instantly through the instantaneous discharging circuit to drive the wireless sensor with a maximum power consumption of 75 mW.