A novel distributed unit transient protection algorithm using support vector machines

Abstract

Based on fault initial angle and transition resistance, a novel ultra-high-speed distributed unit transient protection algorithm is established to protect a busbar and a connected transmission line simultaneously for EHV (extra high voltage) substation through analysing the direction and instantaneous amplitude of the fault-generated high-frequency transient current by utilizing SVM (support vector machine). The fault direction was first judged during the process, and then the fault location was determined by employing different trained SVMs. In addition, the fault initial angle and transition resistance are imported into the input vector of SVMs, through which their adverse effects on the protection performance can be significantly eliminated. Moreover, the proposed algorithm extracts the fault transient information just relying on one transmission line connected to the busbar rather than overall feeders, thus simplifying the process while ensuring high reliability. Further, only typical fault samples instead of all samples are needed during the SVM training procedure, which makes it quite appropriate for practical projects. According to massive simulation results on a typical EHV transmission system on ATPDraw platform, the proposed algorithm can precisely determine whether the fault occurs within the protected busbar or on the protected line or outside the protected area.