微生物燃料电池的电能采集系统

摘要

设计了用于微生物燃料电池的电能采集电路.考虑微生物燃料电池输出功率小(约0.5 mW),不足以直接驱动负载和升压电路,故采用电荷泵收集电池的电量作为后续直流变换电路的启动电压.以超级电容为储能元件,最终直流变换成负载需要的电压.电荷泵和升压电路之间设计了一个电子开关,根据设定的阈值能自动闭合与断开.实验显示:该电路在0.3V,0.5 mA输入时就能开始运行,电子开关在2.2V时闭合,在1.6V时断开,可实现储能电容自动循环充放电,充电速度和输入电压成正比,和储能电容的大小成反比,最终电压变换成3.3V或者5V.实验结果表明:该电路适用于微生物燃料电池电能的采集,能收集污水处理时产生的电能,能间歇地为户外水质检测系统提供电能,实现了燃料电池电能的实用化.%An electric energy harvesting circuit was designed for microbial fuel cells.Because of the account of the low output of the microbial fuel cell(about 0.5 mW),it was inadequate to drive the load or the boosted circuit.Therefore,this paper employed a charge pump to harvest the electric energy of the microbial fuel cell and stored it in a super-capacitor as the starting voltage.A super capacitor was taken as the energy storage component,then,the voltage was transferred to the needed value.An electronic switch was designed between the charge pump and the boost circuit,which could switch on and off automatically according to the setting threshold.Experimental results indicate that the circuit can operate at the input of 0.3 V,0.5 mA.The electronic switch is closed at 2.2 V and opened at 1.6 V,and the charge-discharge in circulation is implemented automatically with a charge speed in direct proportion to the input voltage and indirect proportion to the energy storage capacitor.Furthermore,the final voltage is boosted to 3.3 V or 5 V,which can be changed on the basis of loads.In conclusion,the circuit satisfies the microbial fuel cell requirement of low power input.It can harvest the electrical energy generated from the sewage disposal,and can supply power for a water measurement system in outdoor with an intermittence.