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

With the development of Power System towardsbig unit,higher voltage, biggernetwork,higher automatization. the shortcomings of the conventional electromagneticcurrent transformers are more and more evidence, it is difficult for them to keep upwith thedevelopment of Power System.electronic current transformer (ECT)based onRogowski coil have advantages such as high accuracy measurement,quickrespondence rate,non-magnetic saturation,therefore,it is the hotspot of research indomestic and international. The problem of high potentialcircuit power supply is oneofthekeytechnologyforrealizationoftheECT.Firstly this thesis summarize the status of research about ECT, and the principleof ECT is introduced.The whole design scheme of the ECT based on Rogowski coilsis finished. Then the high potential circuit power supply of ECT is reasearched ,designed a scheme of power supply by laser, introduced the key part ,and reasearchedthe circuit of protecting.The emphases of researchis the scheme of power supply by aspecial CT, but this scheme have two difficult,in the condition of low current inline ,the device must work normally. in the condition of high current,must protectedthe power supply. They are conflict .in order to resolve the problem,this thesis putforward a new scheme of power supply by special CT with compensate function.Analyzed the principle ,and designed the structure. In order to reduce the start-upcurrent, there are some devices optimize for the circuit. Several protecting circuit aredesigned to insure the reliability of power supply and security of the components.Inthe last ,some problems are analyzed that exist in the experiment and some measuresareputforwordtoresolvetheseproblem.In the condition of lab, For the device of power supply that based on special CT,The experimental results showed that the circuit of power supplies can supply thepower above 400mW for the high potential circuit of ECT when the current in linechangefrom6Ato900A. thedeviceissomepracticality.