输电线路在线监测设备供电电源的研制

为研制满足户外输电线路在线监测设备供能的电源,建立取能电流互感器(TA)的功率传递方程,分析输出功率与取能TA变比、磁芯结构及特性参数和负载的关系,进而提出取能TA感应取能和锂电池组联合供电的方案。根据检流电阻测量到的副边电流值和迟滞比较器中设定的上、下限值的比较结果,取能TA可通过继电器自动切换绕组变比以降低电源热耗和增大对线路电流的适应范围。并联接入供电的锂电池组通过另一迟滞比较器减少充放电次数并实现两电池一供一备交替供电。实验测试表明,所提方案设计合理,对负载供能稳定。

Power supply of online monitoring equipment for transmission line

The power supply device of outdoor online monitoring equipment for transmission line is developed.The power transfer equation of draw-out CT is established,based on which,the relationships between the power output and the CT ratio,iron core type and characteristics,and load are analyzed.A cooperative power supply scheme combining draw-out CT and lithium battery group is proposed.By comparing the measured secondary current of draw-out CT with the preset upper/lower current limit of Schmitt circuit,the winding ratio is automatically changed by relay to reduce its power consumption and increase its adaptability to line current.Through another Schmitt circuit,the charge/discharge times of parallel lithium battery group is cut down and the work and backup operating modes are switched over between two lithium batteries.Experimental test shows that the proposed scheme is reasonable,providing load with stable power.