Complex power distribution network fault positioning method based on voltage sag information

Abstract

The invention discloses a complex power distribution network fault positioning method based on the voltage sag information. The method comprises steps that (1), the fault over-current information reported by a feeder monitoring terminal is utilized to preliminarily determine a fault section; (2), the current vector information of a fault uploaded by the feeder monitoring terminal is utilized to determine fault point short circuit current magnitude; (3), the fault point short circuit current magnitude is calculated through utilizing the voltage sag information uploaded by each monitoring point and a system node impedance matrix; and (4), traversal of each node of the system is carried out, a short circuit current offset value is calculated, and a fault node is determined. The method is advantaged in that precise fault positioning of the complex power distribution network is realized, for the actual power distribution network having relatively large-quantity branch lines and the complex structure, the positioning result is relatively accurate, influence of the branch lines can be avoided, influence of grounding resistance, a load model and fault types on the result is relatively small, shortening the fault inspection time of the power distribution network and the user power failure time is facilitated, and a reliability index of the power distribution network is improved.

Description

technical field [0001] The invention relates to power distribution automation and distribution network fault diagnosis, belongs to the field of smart grids, and in particular relates to a complex distribution network fault location method based on voltage sag information. technical background [0002] With the development of our country's economy, the requirements for power quality in all walks of life are constantly improving, and the long outage time will bring serious economic losses. According to statistics, 80% of the power outages of users are caused by the failure of the distribution network. Therefore, after the failure of the distribution network, the realization of fast and accurate fault location can shorten the downtime of the fault and provide the basis for fault isolation and recovery. , and then improve the reliability index of the distribution network. Traditional distribution network fault location methods are mostly based on the fault overcurrent informati...

AI Technical Summary

Problems solved by technology

Traditional distribution network fault location methods are mostly based on the fault overcurrent information uploaded by the feeder terminal unit (FTU), using matrix algorithm or artificial intelligence algorithm to determine the fault section, this location method can only locate the fault to two feeder monitoring Between terminals, the accuracy of positioning results is not high, especially for cable lines, it still requires a long time for fault line inspection

At the same time, due to the low level of distribution automation in my country, most branch lines in the distribution network do not have feeder monitoring units installed, and are only protected by fuses, so the traditional fault location method has a small scope of application.

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