A Nonlinear-estimation Algorithm for Single-Terminal Fault Location Based on The Characteristics ofArc

Abstract

As one of the primary methods, the impedance fault location one based on the single-terminal data is widely used. But for easily infected by the operation condition of the opposite system, it is difficult to estimate accurately. Thus this paper puts forward to a novel nonlinear-estimation algorithm using the characteristics of arc. According to the equivalency of the sequence component of harmonic voltage at the fault point, a nonlinear states estimation method is applied to calculate the fault location on the meaning of the minimum mean square optimal root. In order to avoid the assumption of arc current, the algorithm takes the best use of frequency-amplitude character of the transient arc resistance by Mayr model rather than its detail magnitude information. That gives the equivalent model a much nearly approach to the practical system, and reduces the impaction of the operation manner of the opposite side. Therefore the algorithm presents a novel approach and its location precision of all faults specially the far terminal ones may be favor to improve. For the sake of verify the correctness an accurate 500 kV power system network are made up, which applies distributing parameter transmission line model and takes the character of transient arc into account by Mayr arc model. The results of algorithm testing through computer simulation are presented, too. Those prove that the algorithm is viable