基于功率控制法的电流互感器取电电源设计

Current Transformer Draw-out Power Supply Design Based on Power-controlled Method

根据电流互感器的工作原理,建立了电流互感器取电线圈的负载工作模型,理论论证了取电线圈在未饱和时的输出功率与副边匝数、负载电流、磁化电流等的对应关系,并通过实验验证了理论推导的正确性,在此基础上提出基于功率控制法的电流互感器取电电源的设计方法,通过控制法拉电容充电电流,把取电线圈的输出功率限定在一个较小的范围,从而使电流互感器取电电源可以适应较大的导线电流范围。最终测试结果表明电流互感器取电电源在30A～1000A的电流范围内可稳定输出近1W的功率。

The load model for draw out power winding is established according to operation principle of current transformer, the relationships among power output, second turns, load current and magnetization current is theoretically analyzed when current transformer core is not saturated. Furthermore, its correctness is verified by experiments. Then a novel design method for current transformer draw-out power supply based on power control is proposed. The power output of current transformer draw- out power supply is limited in a narrow range by controlling charge current of farad capacitor, so that current transformer draw- out power supply can adapt for larger range of wire current. Finally, the test result demonstrates that power output of current transformer draw-out power supply is near 1 W for wire current from 30 A-1 000 A. This work is supported by National Natural Science Foundation of China （No. 50977057）.