Research on fault localization method of transmission line based on distributed monitoring

Abstract

Transmission lines are the arteries of power system operation, carrying the important task of conveying electric energy, which is the most fragile and fault-prone place in the power system. This paper first analyzes the traveling wave propagation characteristics of transmission lines. It builds a mathematical model for the refraction and reflection phenomena of traveling waves that occur in the process of readjustment and distribution of transmission lines. The three traveling wave monitoring points nearest to the fault point are used to localize the fault, and the principle of the phase difference of split-phase current is explored based on the fault component. By means of experimental analysis, the phase currents of the three measurement points are detected, and for the transient current waveforms at the time of lightning strikes and short-circuits, the lightning fault localization method of the transmission line based on wavelet transforms is proposed and analyzed for fault localization of the technique. The results of simulation experiments show that when a ground fault occurs in the L1 phase of the line, the current fault components of measurement point 2 and measurement point 3 increase rapidly, and the element between measurement points is more than 10kA. The phase difference of the components is 180°, so the fault interval of the transmission line is from measurement point 2 to measurement point 3, and the fault phase is the L1 phase. Upon analysis, it is apparent that the actual fault distance error of 0.838km is the measurement of the fault distance of the transmission line, and the method proposed in this paper has a high level of measurement accuracy.

Keywords

• traveling wave propagation
• fault localization
• split-phase current phase
• transient current fluctuation
• distributed detection
• 68t05