Fault phase selection method of four loop transmission lines on same tower based on phase-angle difference of circulation flow current

Abstract

The invention discloses a fault phase selection method of four loop transmission lines on a same tower based on phase-angle difference of circulation flow current, which comprises the following steps of: (1) data processing: computing fault current power frequency phasor of each phase of each loop at a line measuring end; (2) decoupling processing: working out a four-loop decoupling transformation matrix of four loop transmission lines on the same tower, carrying out decoupling transformation on the fault current power frequency phasor of each phase of each loop, and working out the power frequency phasor of each sequence of fault current of four modulus of an inflow line at the measuring end of the four loop transmission lines on the same tower; (3) computing the phase-angle difference of the circulation flow current; (4) fault line selecting: establishing criterions for different loop faults and judging fault loops according to the phase-angle characteristics of the circulation flow fault current generated when fault occurs on different loops; (5) computing the phase-angle difference of sequence current; and (6) fault phase selecting: establishing the criterions for the fault of different phases of single loop and distinguishing a fault phase. The method is not affected by system impedance and has the advantage of high accuracy.

Description

technical field [0001] The invention relates to a fault phase selection method for a four-circuit transmission line on the same tower, in particular to a fault phase selection method for a four-circuit transmission line on the same tower based on the phase angle difference of the circulating flow current. Background technique [0002] With the coordinated and rapid development of my country's economy, the power industry, which is the lifeline of the national economy, is in a stage of great development. The scale of the power grid has been rapidly expanded, and tremendous changes have taken place in the structure of the power grid and transmission methods. Among them, due to the dense population of our country, especially the coastal areas such as East China, North China, and South China, there are many private houses, the available arable land is decreasing, the compensation for demolition is getting higher and higher, and the contradiction that the resources of transmission ...

AI Technical Summary

Problems solved by technology

However, due to the very complex coupling mutual inductance between the conductors of the four-circuit line on the same tower, the e

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