UPFC-contained line single-end traveling wave distance measurement method based on fault traveling wave line distribution characteristics

Abstract

The invention relates to a UPFC-contained line single-end traveling wave distance measurement method based on fault traveling wave line distribution characteristics, and belongs to the technical field of electric power system relay protection. A measuring end high-speed collection device obtains measuring end fault current travelling wave data, and voltage travelling waves are constructed by current travelling waves and wave impedance of an adjacent healthy line; secondly, phase-model conversion operation including a faulted phase is carried out to obtain line-model voltage travelling waves and line-model current travelling waves; then, according to line-model currents and line-model voltages, a Bergeron transmission equation is utilized to calculate the line distribution of voltage and current traveling wave abrupt changes, wherein a line calculation step is 0.1 m; and finally, when a measuring end is arranged in time windows, the absolute values of the traveling wave abrupt changes are calculated and then are integrated to obtain distance measurement functions fMuI(x), fMuII(x), fNuI(x) and fNuII(x), and distance measurement of a fault is realized according to the distribution rule of distance measurement function line abrupt changes.

Description

technical field [0001] The invention relates to a single-end traveling wave ranging method for a line containing UPFC based on the distribution characteristics of fault traveling waves along the line, and belongs to the technical field of electric power system relay protection. Background technique [0002] A unified power flow controller (UPFC) is a device that connects two back-to-back converters through a large DC energy storage capacitor, and is an ideal AC-to-AC converter structure. With this structure, active power can flow in any direction between the AC sides of the two converters, and at the same time, two identical converters can independently absorb or emit reactive power at their own AC output terminals . It can be seen from Figure 10-103 that UPFC components are connected in parallel to the system through transformer 1, and UPFC components are connected in series through transformer 2. UPFC injects a voltage with variable amplitude and phase angle into the tra...

AI Technical Summary

Problems solved by technology

Since the compensation device in the line destroys the uniformity of the impedance of the transmission line, the single-ended impedance method based on the power frequency is often used for distance measurement, and the correct fault location is often not obtained.

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