On-line location method of voltage sag source using fuzzy similarity matching

Abstract

The invention relates to a method for positioning a temporary voltage drop source on line by adopting fuzzy similarity match. The method is characterized by comprising the following steps: establishing a node positive sequence voltage match index calculation model by taking the positive sequence voltage of existing nodes of the whole network as a characteristic quantity, and positioning the temporary voltage drop source by utilizing the fuzzy similarity of voltage match indexes and the match index similarity of monitored voltage vectors. The method disclosed by the invention can be used for accurately positioning the temporary voltage drop source by utilizing existing limited monitoring point information. The method disclosed by the invention can be used for calculating the voltage match index of the positive sequence voltage of a node during temporary voltage drop and matching and identifying by utilizing fuzzy correlation degree and a line fault characteristic set established off line, thereby being insensitive to data accuracy. Besides, the method disclosed by the invention can be used for integrally judging and identifying the temporary voltage drop source by simultaneously adopting the information of all monitoring nodes and the information of a network topology, is rich in data source and has certain fault tolerance, and thus high accuracy and universality are achieved in positioning the temporary voltage drop source by utilizing the method.

Description

technical field [0001] The invention relates to an online location method for a voltage sag source using fuzzy similarity matching. Background technique [0002] Among many power quality problems, voltage sag is one of the power quality problems with a high occurrence rate and serious losses. Accurately locating the source of voltage sags is helpful for grid fault location, power quality diagnosis, and formulation of mitigation measures. It is also conducive to distinguishing sag responsibilities and coordinating to alleviate disputes. At present, power quality monitoring devices that have been widely used generally have real-time detection functions, and can perform statistical analysis on the number and magnitude of voltage sags at the monitoring node, and engineering applications for sag location have not yet been realized. [0003] To distinguish sag responsibilities, the fault location of the power grid must be based on accurate voltage sag location, so the accuracy of...

AI Technical Summary

Problems solved by technology

In summary, when there is missing or wrong node information, there will be misjudgment or no judgment, and the accuracy of its engineering positioning is relatively low (<85%)

[0005] It can be seen from the above that the layout limitations of the voltage sag monitoring points make the node monitoring information incomplete, and there are still some problems in the accuracy and practicability of the existing methods for voltage sags in the case of incomplete or wrong information.

Images