针对一直制约其应用的有源型电流互感器高压侧电源的研究难点,分析了目前的几种供电方案后,提出了一种改进的供电方案,该方案将母线电流取能和储能电池供电相结合,两者取长补短,解决了铁心处于饱和状态时,自动重合闸的电源启动速度慢的问题,同时在母线电流很小或断电时能为电流互感器高压侧电路提供稳定电压,有效解决了母线取能供电存在的技术难点.
Active current transformers have wide application prospect in the electrical power system. It has more advantages than traditional electromagnetic transformers and novel optical current transformers for modern electronics devices' cheap price and long period stability. Nevertheless, the electrical power for electronic devices in high-oltage part is very difficult to obtain. It has been an obstacle for industrial application of the active current transformers for a long period. Several kinds of existent electrical power supply scheme has been analyzed in this paper, including obtaining power from main power line, from capacitor current and laser power. This paper brings out an improved power supply method. It adopts the combination power supplying method of obtaining power from main power line and battery energy. The method can learn from one's strong points to offset another's weakness to satisfy the industrial application demands of current transformers. It solves the problem of slow power restart speed in the automatic switch process when the iron core was in saturated condition. At the same time, this power supplying method can provide a stabile voltage for the high-voltage part's electronic devices of the current transformer when the current of main power line is small or power system is failure. Detail circuits scheme of obtaining power from main power line and lithium battery charging manager were given in the paper. At last, important technique parameters and the experiment result were given also. The experiment shows that this method can provide satisfy power and the active high voltage current transformer works well.