Research Of The High Voltage Circuit And Power Supply For Electronic Current Transformer

Electric current transducer is new-style in electronic power equipments. Because the mode of sensor is differ from traditional current transformer, ECT has more advantages than traditional CT, which will make it applied widely in the future electricity system.There are active and passive about Electronic Current Transformer. The active electronic current transformer adopts the sophisticated integrated optoelectronic technology and modern electronic technology. It has played a high-reliability, high-precision and stabilization. It is one of the most practical in future research directions. However, since high-fiber makes transmission insulated between the high-voltage and low-voltage, there isn't any electromagnetic contact between the high-voltage and low-voltage. So, how to supply power for high-voltage circuits become pivotal technology, which is difficulty in research technology.In this paper, the high voltage circuit and power supply for electronic current transformer are studied, the emphasis is power supply. First, the high-voltage circuits of current transformer are studied and designed. Second, several kind of power supply methods which exist at present have been carried on the analysis, aiming at the request of high-voltage power for active electronic current transformer, proposing one kind of improved power supply method in the basis. This method which adopts the mode of the link of the Magnetic induction coil and battery Stored energy supplies power. They make up for one's deficiency by learning from others'strong points.When the iron core is at the saturated condition,in the automatic switch process, the question which the speed of power works slowly is solved, and the dead zone of the current transducer is solved in the small female current or in the power failure situation. Third, the power supply method is designed, The Magnetic induction coil ismade of special material, whose saturation restricts large current, at the same time power converter circuit and large current protection circuit are designed. Li-ion battery is used as storage batteries about stored energy power. To charge for Li-ion battery, a special management IC of charging is designed, which strictly controls the charging and discharging and temperature monitoring for battery. Finally, the experiments about power supply are performed. the starting current about the power induced from line and the location of starting and stopping about Li-ion battery are confirmed by the experiment, in order to resolve the dead zone of the transducer.