The Application And Research Of Electronic Instrument Transformer In Smart Substation

With the huge extension of smart grid, the development of smart substation has entered anew stage, electronic transformer has become one of the important measurement and controldevices of smart substation based on its superior performance. However, the electronictransformer has poor reliability and accuracy when used in the actual situation, and thereforeit is indispensable for us to promote the technology of electronic transformer in order to makea better application of electronic transformer in smart substation.This paper first analyzes the development status and existing problems of electronictransformer, the design of electronic current transformer for measurement which uses theLPCT as its sensor, electronic current transformer for protection which uses the Rogowskicoil as its sensor, electronic voltage transformer for measurement which uses the capacitivevoltage divider as its sensor are put forward after the study of IEC60044-7/8and IEC61850.The design of data acquisition system based on MSP430SCM and merging unit (MU) basedon FPGA&ARM9are adopting. Proper phase compensation scheme can be used in order topromote measurement accuracy of electronic transformer, such as all-pass filter, phase-shiftedalgorithm of data window, phase-shifted algorithm of Fourier, but them both exist insufficientwhen deal with harmonic. On this basis, we put forward the improved schemes of phasecompensation: linear phase of all-pass filter. There are some problems of time synchronizationmode in conventional substation, such as PPS,IRIG-B code, so we can use IEEE1588as timesynchronization mode in smart substation, the principle and method of IEEE1588areanalyzed, after introduce the network model of smart substation, this paper uses a networkplan based on IEEE1588protocol.Finally，we conduct performance tests to the electronic current and voltage transformerdesigned by this paper, these tests includes basic accuracy test, temperature cycle accuracytest, dielectric strength test and so on, The result of the experiment shows that the currenttransformer can meet the class0.2s/5p accuracy requirement, voltage transformer can meetthe class0.2accuracy requirement and with feasibility.