New method for distance protection surge lock of high voltage output line

Abstract

The present invention provides a blocking method of distance protection swing of a high voltage transmission line, the swing blocking technique in the high voltage transmission line distance protection has always been one of the focus discusses. The technical scheme of the invention has two swing blocking methods having different principles, automatically selecting one swing blocking method according the length of the protection line. When the protection judgement is a short line, periodic oscillation change rate and the position of the apparent impedance are real-time detected by a stackable counter, the dwell is relatively adjusted and the relieved, the method is not only applied to the great round covering the small round type operation characteristics, but also applied to the great quadrilateral covering the small quadrilateral type operation characteristics; when the protection judgement is a long transmission line, the swing blocking pattern fpr detecting Ucos fai and its change rate is utilized. Two patterns is automatically switched by the command set in a microcomputer software program, according to the size of the setting impedance.

Description

technical field [0001] The present invention relates to an important field of safe and stable operation of electric power system—relay protection technology of high-voltage transmission lines, in particular to a blocking method for distance protection oscillation of high-voltage transmission lines. Background technique [0002] Oscillation blocking technology in distance protection of high-voltage transmission lines has always been one of the focus issues. The so-called oscillation blocking technology not only requires that the distance protection can be reliably blocked to prevent misoperation when the system oscillates, but also must be released immediately when a fault occurs during the oscillation process to allow the distance relay to trip. Two methods of oscillation blocking have been widely used so far: one is to delay the action of the protection, and the other is to check the change speed of the electrical quantity. [0003] According to the analysis of Document 1 ...

AI Technical Summary

Problems solved by technology

The same disadvantage of this method is that the size of the oscillation period is not measured in real time, so the setting value of the action time difference can only be set according to the shortest oscillation period. At this time, if a fault occurs, the protection device can only trip with a delay determined by the previous method.

The traditional distance protection in operation now uses the same method to realize oscillation blocking regardless of the length of the line, which is also a big disadvantage.

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