Fault location method based on single terminal electric quantity and not affected by transition resistance

Abstract

The invention relates to a fault location method based on single terminal electric quantity and not affected by transition resistance. The method comprises: the system voltage and current after a fault are subjected to phasor analysis, and a phasor diagram of the measured current and the measured voltage of a protection installation position, the voltage and the current of a fault point and the voltage of a fault line is obtained; a vertical line perpendicular to a voltage vector of the fault line and a vertical line perpendicular to a voltage vector of the fault point are added to the phasor diagram to construct a similar triangle; according to the post-fault voltage and current phasor diagram, with the constructed auxiliary lines and analytical geometric knowledge combined, each side and angle of the similar triangle is solved; and the similarity principles are used to construct an equation for solving the fault distance percentage to solve a fault distance. The method can obtain the fault distance accurately by using only the single-terminal electric quantity information, and is not affected by the transition resistance. The algorithm is simple, easy to implement and universal. The method is suitable for various short-circuit fault types and system operation modes.

Description

technical field [0001] The invention belongs to the field of line relay protection, and in particular relates to a fault distance measurement method based on single-ended electrical quantity and not affected by transition resistance. Background technique [0002] The power system is a complex nonlinear dynamic system. Large-scale interconnection makes the geographical coverage of the power grid wider and the coupling between regions is enhanced. After the power grid fault occurs, it will accelerate the spread of the fault and lead to catastrophic large-scale power outages. Therefore, the power system Safe and reliable operation has become the primary issue facing the entire system. With the continuous expansion of the grid scale, the transmission distance of electric energy is getting farther and farther, and the voltage level of transmission lines is getting higher and higher. One of the problems brought about by long-distance power transmission and the construction and us...

AI Technical Summary

Problems solved by technology

Although the double-ended ranging method can make full use of the voltage and current information on both sides of the system, and can obtain more accurate ranging results, but requires more data transmission; The method is easily affected by the transition resistance of the fault point, which will cause a large error in the ranging result

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