Method for comparing and judging phase of single-pole adaptive reclosure of electric transmission line

Abstract

The invention discloses a method for comparing and judging the phase of a single-pole adaptive reclosure of an electric transmission line, which comprises the following steps of: 1) collecting a voltage value and a current value at one side of the line, and converting the voltage value and the current value into the mode of phase quantity; 2) defining a fault phase through a phase selecting component in a line protecting device; 3) computing a computation fault phase terminal voltage value when having the temporary fault under the current system running state through a temporary fault model, and respectively subtracting an undervoltage compensation quantity and an overvoltage compensation quantity by taking the computation fault phase terminal voltage value as the cardinal number, and comparing a value which is obtained by the means that the computation fault phase terminal voltage value subtracts the undervoltage compensation quantity with a value which is obtained by the means that the computation fault phase terminal voltage value subtracts the overvoltage compensation quantity; and 4) judging to be a permanent fault and not overlapping the reclosure if the differential value of a phase quantity and a phase angle of a comparison value in the step 3) is less than a set value; otherwise, judging to be a temporary fault and exporting the reclosure.

Description

technical field The invention relates to the field of relay protection of power system transmission lines, in particular to a phase comparison and discrimination method for single-phase self-adaptive reclosing of transmission lines. Background technique Automatic reclosing technology is one of the important measures to ensure the safe power supply and stable operation of the power system. Since most of the faults on ultra-high voltage transmission lines are transient faults, putting the line back into operation after the fault is eliminated can effectively improve the stability of the power system and the quality of power supply to users, so the automatic reclosing technology is currently widely used in power systems. Among all kinds of faults in power lines, single-phase grounding faults account for more than 80%. Therefore, it is of great practical significance to study single-phase automatic reclosing technology. However, the current single-phase automatic reclosing tec...

AI Technical Summary

Problems solved by technology

The voltage discrimination method uses the characteristics of capacitive coupling voltage to distinguish between transient faults and permanent faults. Its sensitivity is related to transition resistance and line length. Due to the influence of electromagnetic coupling voltage, there is a possibility of misjudgment in the voltage discrimination method.

For transmission lines with shunt reactors, due to the influence of shunt reactors, the electrical quantities on the disconnected phases have beat frequency characteristics, and there is a possibility of misjudgment by using the voltage discrimination method and the current discrimination method.

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