Fault localization method suitable for three-terminal T connection electric transmission line

Abstract

The invention discloses a fault localization method suitable for a three-terminal T connection electric transmission line, comprising the following steps: firstly, judging the running state of the three-terminal electric transmission line: if the line is in a three-terminal running mode, firstly identifying a fault branch line, and calculating the fault distance according to the electric quantityof both ends of a T connection point and the endpoint of the fault branch line; if the line is in a two-terminal running mode or one side branch line is in a three-terminal running mode in a hot standby state, firstly determining if a fault point is at a switch cut-off branch line or not, if so, adopting a single-terminal localization method to calculate the distance from the T connection point tothe fault point, thereby obtaining the fault distance from the endpoint of the branch line to the fault point; but if the fault point is not at the switch cut-off branch line, respectively carrying out fault localization calculation under the two-terminal running mode or the three-terminal running mode. The invention provides a fault localization method before/after converting the running mode ofthe three-terminal electric transmission line and a fault localization method when the line is in the two-terminal running mode or one side branch line is in the three-terminal running mode under thehot standby condition.

Description

technical field [0001] The invention belongs to the technical field of electric power system automation, and relates to a fault location method suitable for three-terminal T-connection transmission lines. Background technique [0002] In the high-voltage power grid, with the development of the power system, the increase of load density and the difficulty of land acquisition for new substations, high-voltage heavy-load three-terminal T-connected transmission lines often appear. In order to speed up the removal of line faults and reduce the economic losses caused by power outages, it is necessary to use high-precision fault location technology. However, due to the particularity of the structure of the three-terminal transmission system, the fault location method of the single-terminal electrical quantity cannot determine the location of the fault point on the three-terminal system, and although the algorithm for the two-terminal system is relatively mature, it is difficult to ...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned various fault location methods are all distance measurement calculations when the three-terminal transmission lines are in normal operation. Case

As for the fault location switching scheme before and after the conversion of this operation mode, most of them ha

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