High voltage circuit phase selection method based on pallern identification

Abstract

This invention discloses a method for selecting the phase of the high voltage power lines on the basis of the model distinguishing and is used for the phase selecting components during oscillation blocking. It is characterized in that the model distinguishing method is adopted to calculate respectively the distances and the three orders voltages at the failure sites under two failure models, which are the models of the single phase grounding and the double phases short circuiting grounding when a grounding failure occurs, determining the actual phases on which the failure occurs through judging whether or not the three orders voltage meet the boundary conditions under the corresponding failure.

Description

1. Technical field [0001] The invention relates to the protection of high-voltage transmission lines in electric power systems, in particular to a method for phase selection of high-voltage lines based on model recognition. 2. Background technology [0002] At present, the domestic digital high-voltage line protection mainly adopts the combination of abrupt amount phase selection and steady state amount of phase selection. The first phase selection after the protection starts is to use phase current difference abrupt amount phase selection, because it is not affected by the load current. , has a high phase selection accuracy; the phase selection element during the oscillation blocking period, due to the difficulty of extracting the sudden change, adopts the steady-state quantity phase selection, and generally adopts the partition of the sequence current combined with the impedance comparison method. [0003] In the sequence component phase selection, the ground fault adopts ...

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Problems solved by technology

During the oscillation blocking period, the measured impedance (especially the non-faulted phase) is greatly affected by the system oscillation. The auxiliary component of the measured impedance comparison will misselect the single-phase ground as a two-phase short-circuit ground fault, and also misjudge the two-phase short-circuit ground fault. It is single-phase grounding, and its ability to withstand transition resistance is also very poor, which is a major hidden danger in the current high-voltage transmission line protection

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