Design Of The Test System For Electronic Transformer

Digital Technology is a cutting-edge technology in today’s scientific technology,and is the future progressive direction of substation construction.In the digital substation,Digitization of process layer is mainly reflected on the use of electronic transformer,which put the high voltage and high current on the transmission line down to the standard values of instrument direct measurement or various relay protection according to certain proportion relationship.Electronic transformer is the important data source of power system relay protection device and electronic energy metering device,so the stability of the engineering application for electronic transformer plays a key role in the digital substation process.Therefor,it puts forward new requirements on electronic transformer test system.Nowadays,with the rapid development of computer technology and network communication technology,the new test system based on virtual instrument technology arises at the historic moment.The external interface equipments based on PC are in charge of acquisition and regulation for signal, the software program of LabVIEW completes operation,analysis and processing for signal,so s set of automatic test system can be formed on account of the computer.In this paper,I focus on the electronic transformer of Rogowski coil and determine test method and indicators.Using the virtual instrument technology and high-precision data acquisition device,and analyzing the static test system,typical modeling and dynamic characteristic,I design a set of test system of virtual instrument technology for electronic transformer,which has friendly human-machine interface,high-precision and easily expanded function.The static test is composed by test method and indicators,selected hardware,the designed LabVIEW software and the showed test results four part.It applies the high-speed synchronous data acquisition card to acquire the measured qualities and uploads to the PC for data analysis.It can display the performance test results of the amplitude and phase difference and meet the 0.2 accuracy requirements.In the dynamic test,I set up the typical mathematical model of Rogowski coil electronic transformer and use selected structure parameters to simulate.Regarding the integrator link of having more influence on the dynamic characteristics,it evaluates the dynamic performance from analog and digital two forms,and proves that the digital integrator has higher precision.And the results of higher harmonics simulation test conform to the stipulated standard in the harmonics accuracy requirement.