Controllable zero sequence current distribution network earth fault positioning device

Abstract

The invention discloses a controllable zero sequence current distribution network earth fault positioning device. The controllable zero sequence current distribution network earth fault positioning device includes a key station processor (6), a fault point indicator (3) which is electrically connected with the key station processor (6), and a signal source which is electrically connected with a bus (ABC), wherein an input end of the key station processor (6) is electrically connected with a secondary side terminal (4) of a bus voltage sensor; an output end of the key station processor (6) is electrically connected with a control end of a three phase synchronized operation switch (2); and the signal source is in bridge connection between a bus terminal (1) and a grounding terminal (7) after being connected with the three phase synchronized operation switch (2) and an impedance grounding transformer (5) in series, and is used for instantaneous closure of the three phase synchronized operation switch (2) when the bus voltage sensor monitors occurrence of a singlephase earth fault. The controllable zero sequence current distribution network earth fault positioning device has extremely high fault positioning accuracy, and can be widely used for positioning areas for a singlephase earth fault area of a neutral point not-direct-grounding power grid system.

Description

technical field [0001] The invention relates to a fault location device, in particular to a controllable zero-sequence current distribution network grounding fault location device. Background technique [0002] In my country's 3-66kV power grid system where the neutral point is not directly grounded, single-phase ground fault is the most common fault. When a single-phase ground fault occurs, it is necessary to find out the faulty branch and deal with it in time, otherwise, it is very easy to cause a large power supply and distribution safety accident. At present, in order to obtain the fault location as soon as possible, people have made various efforts, such as the title "A Distribution Line Fault Automatic Locating System Based on Fault Indicators", "Electric Power Equipment", Volume 6, Issue 10, October 2005 66 - 67 pages of articles. The fault location system mentioned in this article is mainly composed of a large number of fault probes installed on the branch lines at...

AI Technical Summary

Problems solved by technology

Although this fault location system can locate single-phase ground faults, it still has shortcomings: it can only accurately locate low-impedance single-phase ground faults, so the zero-sequence current in the power grid system is relatively large, and the fault The characteristics of the signal collected by the fault point indicator on the branch are obvious-accurate positioning; however, when a single-phase ground fault with medium impedance or high impedance occurs, because the zero-sequence current of the grid system itself is very small, the characteristic quantity is not obvious, so lead to inaccurate positioning

Images