Smart Traveling Wave Fault Location System Based On Electronic Transformer

Digital substation is a key node of the smart grid, and electronic transformer is the basic equipment of the digital substation. The existing electronic transformer’s data synchronization method cannot meet the practical demand, key progress has not obtained about the research of transient traveling wave signals’transmission and conversion for the electronic transformers.One of the main functions of the reliable and security operation of smart grid is the rapid and reliable detection of the failure of the transmission grid. The traveling wave ranging technology based on transient information is being perfected, coupled with its inherent ranging error is small and its applicability, making it more and more widely used in locating transmission line fault. Traditional traveling wave fault location algorithms have different inadequacies, and traditional traveling wave fault location devices only receive the analog signal, unable to meet the demand of digital substation, the digital substation standard IEC61850has no detailed description about the device based on transient traveling wave, no logical node and equipment device to process the device.This paper studies the smart traveling wave fault location system based on the electronic transformer, main research work and contribution as follows:According to the different requirements for electronic transformer’s data synchronization, three electronic transformer data synchronization ways are studied: the first method is based on the cubic spline interpolation theory, the second method is based on the high-speed redundant sampling process layer data mix and the third is based on the IEEE1588precision clock protocol, the experimental results verified the validity of the three data synchronization methods;Recently electronic current transformer (ECT) based on the Rogowski Coil is widely used, this study take that into research, deeply studied the factors that affecting the traveling wave signal’s transmission and conversion of the Electronic Current Transformer, analysis the transient characteristics and the response to the traveling wave signal of the electronic current transformers, aiming at the analysis of the traveling wave sampled values under IEC61850, The system of ECT which is suitable for Traveling Wave Transfer is designed and its experimental results verified its validity;Traveling wave fault location algorithm for Least Squares Support Vector Machine (LS-SVM) Combined with HHT is proposed, and the traveling wave head’s arrival time is obtained by the algorithm, according to the double-ended ranging principle (or the single ended) to accomplish fault location;The digital traveling wave fault location device is designed.This device can directly receive the traveling wave sampling values that satisfied the IEC61850standard, and could automatically uploaded to the substation and scheduling the fault message which is standards-compliant. The device could fully meet the requirements of the digital substation for fault location system.The server model and logic device model of the digital traveling wave fault location device is studied, the service mapping in the practical application is detailed analyzed. The establishment of the digital traveling wave fault location’s information model making it possible to interoperability and seamless integration among other intelligent electronic devices (IED), at the meantime, the problem of the general statute of IEC61850of digital substation lacks the digital traveling wave fault location’s information model is solved.