Comparative Analysis On The Influence Of Electronic Transformer On The Accuracy Of Traveling Wave Fault Location

One of basic electrical equipment of digital substation is electronic transformer. Digital substation is a measure of the key indicators, is also an important part of the smart grid construction process, so the popularity of smart grid, smart grid construction cannot do without the digital substation. To develop electronic mutual inductor is an indispensable step in the development of smart grid. The safety and reliability of power grid operation is inseparable from the rapid and accurate fault location and faults occur in the transmission line after precise fault location technique for the development of smart grid, is important one part, traveling wave protection in the aspects of fault location has its unique advantages. Based on electronic transformer of traveling wave fault location technique for smart grid power supply reliability has important significance and effective of traveling wave fault location device is in urgent need of digital substation. Therefore, it is indispensable to research the traveling wave protection based on electronic transformer.This paper introduces to the concept and the classification of electronic transformer and expounds its working principle. Through the analysis of two kinds of equivalent circuit of electronic transformer, its simulation model is established.Electronic transformer of transient characteristics were investigated by model simulation, key analysis sampling resistor for 10?,100?,1 k? electronic transformer transient characteristic, when the sampling resistor is 10?, the transient characteristics of electronic transformer is best, when sampling resistor of 100?, better transient characteristics of electronic transformer, when the sampling resistor is 1k?, the transient characteristics of electronic transformer is poorer. Through the simulation analysis, comparison of electronic transformer, two sides of the voltage and current, the conclusions are as follows:Resistive-capacitive branch voltage type EVT and Rogowski coil ECT can accurately transmission of traveling wave signal.The influence of the traveling wave ranging accuracy is investigated by the sampling resistance value of in,10?,100?,500?, EVT and ECT respectively. When the sampling resistance of the electronic transformer is 1?,10?, the EVT secondary traveling wave signal and the ECT secondary traveling wave signal are used for fault location With the reliable accuracy of the two, the error is within 500 meters, and the error is little difference; When the line fault occurs at 10km, the EVT's ranging error is a minimum of 20m. And with the electronic transformer sampling resistor value increasing, single-ended traveling wave distance error also increases, When the sampling resistance is 500?, traveling wave distance failed, and the use of ECT for ranging When the error is significantly greater than when using EVT error, EVT is more suitable for traveling wave fault location.