Identically named fault phrase sequence diagnosis method of double-circuit lines on the same tower

Abstract

The invention discloses an identically named fault phrase sequence diagnosis method of double-circuit lines on the same tower. Firstly, a fault phrase current mutation in the I-circuit line protection installation place of the double-circuit lines on the same tower and a fault phrase current mutation in the II-circuit line protection installation place of the double-circuit lines on the same tower are measured. Then the angle Arg advanced by to is calculated. Thirdly, two types of faults in a Phi phase circuit line of a one-circuit line and a Phi phase circuit line of double-circuit lines will be actually discriminated based on the magnitude of the Arg . If a fault occurs in the Phi phase circuit line of the one-circuit line, two types of faults in the Phi phase circuit line of the one-circuit line and the Phi phase circuit line of double-circuit lines will be accurately judged based on the magnitude relationship between and . According to the identically named fault phrase sequence diagnosis method of double-circuit lines on the same tower, accurate diagnosis of the identically named fault phase sequence of double-circuit lines is achieved through the application of amplitude and phase characteristics of the identically named phase fault phase current mutation of double-circuit lines, and the judging result is not affected by zero-sequence mutual inductance between lines, position of fault point, saturated or unsaturated state of a current transformer, fault type, transition resistance and the load current.

Description

Technical field [0001] The invention relates to the technical field of power system relay protection, in particular to a method for diagnosing the phase sequence of a fault with the same name in a parallel double-circuit line on the same pole. Background technique [0002] Parallel double-circuit lines on the same pole have a small footprint, low cost, stable and reliable operation of connecting to the grid, and have become a common transmission line connection method for power systems. There are 14 types of phase faults with the same name on the double-circuit line on the same pole. The positive and negative zero sequence currents extracted by the symmetrical component method no longer have the traditional electrical and physical meaning in the double-circuit line on the same pole. The amplitude characteristics or phase characteristics between the positive and negative zero-sequence currents extracted by the component method are used for fault phase selection, which cannot provi...

AI Technical Summary

Problems solved by technology

There are 14 types of phase faults with the same name in parallel double-circuit lines on the same pole. The positive and negative zero-sequence currents extracted by the symmetrical component method no longer have traditional electrical The amplitude characteristics or phase characteristics of the positive and negative zero-sequence currents extracted by the component method are used for fault phase selection, which cannot provide accurate fault phase distinctions, and cannot be used for I-section grounding distance protection, I-section phase-to-phase distance protection, and single-phase coincidence. The gate provides accurate fault phase distinction, so that the protection device cannot jump off the faulty phase correctly, but trips the double-circuit line as a whole, causing further impact on the power grid and affecting the safe and stable operation of the power grid

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