Single-ended phase-to-phase fault location method for distributed capacitance current and fault resistance resistant line

Abstract

The invention discloses a single-ended phase-to-phase fault location method for a distributed capacitance current and fault resistance resistant line. The method comprises the following steps of: calculating the angle of a fault phase-to-phase action voltage phasor ahead of a fault phase-to-phase current break variable of each point on the line in turn from the starting end of a protected line by a method of increasing a step length successively until a setting range for sending a tripping signal; if a protection tripping signal cannot be obtained, searching the overall length of the protected line; and taking the angle of the fault phase-to-phase action voltage phasor ahead of the fault phase-to-phase current break variable lying within the interval of [180 degrees, 360 degrees] at a certain point and the angle of the fault phase-to-phase action voltage phasor ahead of the fault phase-to-phase current break variable laying within the interval of [0 degree, 180 degrees] at a point adjacent to the point, wherein the middle position between the two points is a fault point; and the distance from the fault point to a line installation position is fault distance. The method is not influenced by distributed capacitance, fault resistance and a load current and has a very high practical value.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a single-end ranging method for interphase faults of lines against distributed capacitive currents and fault resistances. Background technique [0002] The high-voltage transmission line is the main artery of the normal operation of the power grid. It is not only responsible for the task of transmitting huge power, but also the link for the network operation of the major power grids. Its operation reliability affects the reliability of the power supply of the entire power grid. most places. When a fault occurs on a high-voltage transmission line, accurate fault location can save a lot of manpower, material and financial resources spent on line hunting, speed up power supply recovery, reduce economic losses, and improve operational reliability. Accurately and quickly determining the fault location is an important measure to improve the safe operat...

AI Technical Summary

Problems solved by technology

In the case of medium and low-resistance short-circuit faults, due to the obvious drop in voltage along the line, the error in estimating the voltage phase angle of the fault point by using the negative-sequence current phase angle at the observation point has little effect on the ranging results; but in the case of high-resistance short-circuit faults, Because the voltage difference of each point along the line is very small, the error in estimating the voltage phase angle of the fault point by using the negative sequence current phase angle at the observation point plus the influence of the transient process, the distance measurement error of this method is relatively large

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