Research on Asymmetrical Fault Location in Transmission Lines Based on Sequential Components

For transmission lines, fault recording devices along the line provide important fault information. Aiming at the existing double-ended electrical quantity fault location algorithms that require the line parameters to be known, complicated calculation and other problems, the symmetrical component fault location method is proposed based on the transmission line model of medium-length line using the double-ended fault recording electrical quantity of the line without adding additional equipment, decomposing the original network with asymmetrical current and voltage into three symmetrical networks of positive, negative, and zero-sequence, and utilizing the line's positive-sequence and negative-sequence networks. Using the positive sequence and negative sequence networks, by analyzing the relationship between fault distance and double-ended electrical quantity under the positive and negative sequence networks, the locating equations are deduced and established, so as to simplify the operation and eliminate the locating errors brought by transition resistance, line parameter changes and complex calculations. Through simulation analysis, the algorithm has high accuracy for asymmetric fault location in transmission lines.