Waveform Similarity Comparison Protection Scheme for Multi terminal Distribution Network Based on Fault Self-synchronization and 5G Communication

Abstract

Abstract With the wide access of distributed new energy, how to quickly identify and accurately isolate the fault of distribution network is a key technical problem to be solved in the industry. Due to the numerous branches of the distribution network, the imperfect data acquisition network, and the transmission error of the transformer, there is an urgent need for new means to cope with the synchronization problem of data acquisition in different locations. To solve the above problems, firstly, the characteristics of multi terminal distribution network in case of fault are analyzed, and the automatic synchronization of protection data is realized by detecting the abrupt points of signals at different locations; Secondly, the information of each node in the distribution network is transmitted to the substation in real time through the 5G network, and the decision-making center connects the distribution lines with multiple branches for information synthesis to form a double ended line form that is convenient for calculation and comparison; On this basis, through the tanimoto waveform similarity algorithm, the correlation coefficients of current waveforms at both ends of each line are compared to determine whether they have failed, and finally a new scheme of fast protection for multi terminal distribution network suitable for distributed new energy access is formed. By building the distribution network model in PSCAD/EMTDC, the effectiveness of the proposed protection scheme under various fault scenarios is verified. Compared with the traditional over-current protection scheme, it has faster action speed and higher reliability, and has good practical value.