Fault distance measuring and calculating method for power transmission line based on synchronous sampling device

Abstract

The invention discloses a fault distance measuring and calculating method for a power transmission line based on a synchronous sampling device. The method comprises the following steps of: (a) calculating the fault current component of a power transmission line in fault; (b) calculating the fault current positive-sequence component, fault current negative-sequence component and fault current zero-sequence component of the power transmission line, and judging the type of a fault of the power transmission line; (c) calculating an included angle between the fault current positive-sequence component and the fault current negative-sequence component, and judging the phase of the fault suffered by the power transmission line; (d) judging the fault direction of the faulty line; and (e) calculating the distance Lk from a fault point to the synchronous sampling device according to a voltage value and a current valve which are acquired by the synchronous sampling device. The method has the advantages that the location of the fault point can be accurately calculated so as to more accurately locate the fault point, and the fault removal cycle is further shortened on the basis that the reliability and accuracy of fault distance measurement are guaranteed.

Description

technical field [0001] The invention relates to a distance measuring method in a power system, in particular to a distance measuring method for a transmission line fault point. Background technique [0002] Among the faults of power transmission and transformation facilities in the power system, the faults of transmission lines account for the vast majority. After a transmission line fault, how to quickly and accurately find the fault point and correctly determine the fault type is the most concerned issue for transmission line professionals. Preliminary judgment of fault point and fault type can be carried out through protection action status, protection distance measurement, fault recording chart, weather conditions, operating environment, etc. Accurate judgment should be made based on fault phenomenon and fault point location after finding the fault point. [0003] After a fault occurs on a high-voltage transmission line, a transient traveling wave running to both ends w...

AI Technical Summary

Problems solved by technology

In the existing traveling wave ranging method, the arrival time of the wave head and the traveling wave velocity are the two main factors affecting the ranging accuracy, but the existing traveling wave ranging method needs to be calculated with the aid of transformer measurement, and Due to the limitation of the frequency band of the traditional transformer, there is a large error in the measurement of the traveling wave head, which affects the accuracy of fault location and reduces the reliability of positioning