Study On The Effect Of The Fiber Optical Current Transformer And Electromagnetic Current Transformer Mixed Application Of Relay Protection Based On RTDS

With the worldwide smart grid national strategy to promote, intelligentsubstationconstruction as an important foundation for the smart grid has become a hot spot, and from2005began with the electronic transformerand the IEC61850standard as the pilotconstruction of digital substationtwo features has been transformed into the pilotconstruction of smartsubstation, and the construction of smart substation also performanceof the current transformer is put forward further requirements.The traditional electromagnetic current transformer structure and similar to thetransformer, the electromagnetic coupling between the one or twowindings, the electricquantity information from one side to the two side,between the core and the winding andthe one or two winding is neededinsulation structure of sufficient strength to ensure allequipment, low voltage and high voltage isolation. But with the increase of thetransmission capacity of the power system, the voltage level is getting higher and higher,the current transformer of this kind of structuredefects is more and more outs tanding. Allfiber optical currenttransformer is essentially a kind of based on the interference ofpolarized light optics instrument based, optical polarization control is one of thekeytechnology, the form of realization of the optical measurement principle and the use ofoptical fiber transmission of digital signals, the digital transmission of electricityinformation source. Compared with thetraditional electromagnetic current transformer,fiber optical current transformer has a large dynamic range, high precision, good linearity,no magnetic saturation, small volume, light weight, one or two completeisolation, low sideno open. Currently in the pilot project of intelligent substation and non pilot project, allfiber optical current transformer is applied in different voltage grade, accumulated richexperience, product maturity has been continuously improved, and has wide applicationprospect, has become one of the important characteristics of the new generation ofintelligent substation. Although the advantages of all fiber optical current transformers aremany, but at present all fiber optical current transformer is based on engineeringapplication stage, and its high cost, long term stability still need to test and other factors,especiallyin practical engineering, and the traditional current transformer using a mixtureof reliability problems still need further research.In this paper, a220kV Smart Substation in66kV side different principle of currenttransformer mix (66kV side in addition to low pressure side of main transformer intervalsusing all fiber optical current transformer,other intervals are still using the traditional electromagnetic current transformer) situation as the research object, based on the useofsituation in the full investigation and study of all fiber optical current transformers. Theprinciple, technical characteristics, summarized the full optical fiber current transformer, afull analysis of the possible problemsusing different mixing principle of currenttransformer, through the simulation of real time digital simulation system RTDS modeling,a comprehensive assessment of two different principle of currenttransformer mixed use,the action of busbar protection is correct.Through the research work can fill the blank inChina and abroad,analysis of different principle of current transformer mixed useofsimulation experiment, provides the data support for the engineering application andacademic research.