结合超级电容与锂电池的CT取能电源研究

Study on the current transformer energy-absorbing source combined with super capacitor and lithium battery

分析对比输电线路在线监测设备的供能方式,针对课题组现有电流互感器(CT)取能电源存在的效率低、铁芯易饱和、输出电压不稳定、存在供电死区等缺陷,提出了一种结合超级电容与锂电池的CT取能电源。利用穿心式铁芯作为取能CT,将大容量超级电容接于整流电路之后,通过分析电容电压与CT取能效率之间的关系,选择合适的电容电压达到最高效率。另外,通过处理电路和锂电池,使CT在不同的输电线电流下工作在断续取能或者全时取能状态,实现一次电流在很小至较大范围波动时电源能够为负载提供稳定的直流电压。测试数据表明,研制的CT取能电源输出功率足够满足要求,能有效防止CT饱和,工作稳定可靠,无供电死区,并具有较大的瞬时功率。

By analyzing various power supply sources for on-line monitoring device along transmission line,a newly current transformer （CT） energy-absorbing source combined super capacitor and lithium battery was put forward to amend the drawbacks of the existing one for our research group,namely inefficiency,core saturation,output voltage instability and dead zone.High-capacity super capacitor with ideal filtering effect and anti-saturation performance were put just after the rectifying circuit.Moreover,the relation between capacitor＇ voltage and core＇s power-absorbing efficiency was analyzed to obtain the proper value of capacitor voltage that is helpful for CT to remain the highest efficiency absorbing energy from transmission line.In addition,CT can work very well in different conditions along with different line currents through managing circuit and lithium battery.The test data verified that the newly developed CT energy-absorbing power source had advantages such as high efficiency,non-saturation state of CT,stable operation,eliminated dead zone of power supply and large instantaneous output power.