CN205038282U

CN205038282U - Asymmetric current source earth fault detection device

Info

Publication number: CN205038282U
Application number: CN201520744352.8U
Authority: CN
Inventors: 王兵兵
Original assignee: JIANGSU WINET ELECTRIC Inc CO Ltd
Current assignee: JIANGSU WINET ELECTRIC Inc CO Ltd
Priority date: 2015-09-23
Filing date: 2015-09-23
Publication date: 2016-02-17
Anticipated expiration: 2025-09-23

Abstract

The utility model relates to an asymmetric current source earth fault detection device mainly comprises high -pressure wall bushing, sample module, high pressure controller, obs core control module, fault indicator and GPRS communication module, and the sampling module is mainly formed by the embedment of electron PT, and the three -phase high voltage transmission lines that the wall bushing was drawn forth is connected respectively to the once end of sampling module, and the synthetic zero -sequence voltage for star connection is held to the secondary of sampling module, reach certain numerical value when the zero -sequence voltage value, obs core control module control high pressure controller produces the characteristic current signal, and fault indicator detects the judgement of making earth fault behind this characteristic current signal, and GPRS communication module is with the relevant information teletransmission in obs core control module control simultaneously, the utility model discloses the scheme can effectively improve small current neutral grounding sys tem phase to earth fault's detection rate of accuracy, and the phase to earth fault that effectively contracts investigates the time, reduces loss of outage and has increased service reliability, has important social and economic benefits.

Description

Asymmetric current source ground fault detection device

Technical field

The utility model belongs to small current neutral grounding system Earth Fault Detection technical field, the pick-up unit of the singlephase earth fault of especially a kind of distribution isolated neutral or compensated distribution network.

Background technology

China 3 ~ 35kV electric system great majority adopt isolated neutral or the method for operation through grounding through arc, are small current neutral grounding system; In small current neutral grounding system, single-phase earthing is a kind of most common failure; 10kV distribution line is in actual motion, and because circuit is long, distribution range is extensive, has the existence of distribution line regardless of various MODEL OVER COMPLEX TOPOGRAPHY such as city, rural area, mountain areas; The above-mentioned characteristics determined of distribution line singlephase earth fault has the features such as multiple, disguised, complicacy, and particularly under the severe weather conditions such as rainy season, strong wind and snow, singlephase earth fault frequently occurs especially, searches more difficult; One of prior art, adopt capacitor pulse amplitude method, in substation grounding route selection, the transient state capacitance current amplitude that can gather all outlets compares, amplitude maximum be exactly earth fault line; And when using this principle in fault detector, due to the transient state capacitance current amplitude of other circuit cannot be measured, therefore cannot compare, so these producers all set a fixing threshold value at present, when the amplitude of capacitance current pulse is greater than this threshold value (simultaneously voltage-to-ground decline 3kV), then think generation earth fault, board turning shows; Capacitor pulse amplitude law technology shortcoming: Threshold selection is very difficult---pulse amplitude size and stake resistance, system over the ground equivalent capacity, line equivalent sense, earthing position have relation from transformer station is far and near etc.; Average threshold cannot meet various informative distribution line, causes its accuracy in detection low; Prior art two: first half-wave method, the first half-wave of capacitance current of sampling ground connection moment and voltage waveform, compare its phase place; When the first half-wave of sampling ground connection capacitance current instantaneously and the voltage-phase of ground connection moment meet certain relation, wire voltage-to-ground reduction simultaneously, then judge circuit generation earth fault; First half-wave method shortcoming: installed and used directivity requirement, for ring network power supply, after circuit falls load, direction is originally just wrong; Installation has directivity, adds many workloads.

Utility model content

The utility model object provides a kind of asymmetric current source ground fault detection device to overcome the deficiencies in the prior art, solve the bad problem determining easily to produce wrong report of " capacitor pulse amplitude method " threshold value, solve again the problem of " first half-wave method " inapplicable ring network power supply, substantially increase the accuracy that single-phase grounded malfunction in grounded system of low current detects.

For achieving the above object, the technical solution adopted in the utility model is: asymmetric current source ground fault detection device, described pick-up unit is primarily of three high-voltage wall bushings, three sampling module, Hi pilot, kernel control module, fault detector and GPRS communication module compositions, described three sampling modules form primarily of electronics PT embedding respectively, the three-phase high-voltage circuit once holding connection three wall bushings respectively to draw of sampling module, the secondary terminals of three sampling modules is the residual voltage of star connection synthesis; Described fault detector hangs on the line; When residual voltage value reaches certain numerical value, kernel control module controls Hi pilot and produces characteristic current signal, the judgement of earth fault made by fault detector after this characteristic current signal being detected, kernel control module controls GPRS communication module by relevant information teletransmission simultaneously.

Improve further as the utility model, described Hi pilot adopts vacuum high-pressure contactor as high-voltage switch gear.

Due to the utilization of technique scheme, the utility model compared with prior art has following advantages: asymmetric current source ground fault detection device, effectively can improve the Detection accuracy of single-phase grounded malfunction in grounded system of low current, effective shortening singlephase earth fault investigation time, reduce loss of outage and add power supply reliability, there is important social benefit and economic benefit.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, technical solutions of the utility model are described further:

Accompanying drawing 1 is asymmetric current source ground fault detection device structural representation of the present utility model;

Accompanying drawing 2 is the asymmetric current source characteristic current loop formation basic theory schematic diagram of asymmetric current source ground fault detection device of the present utility model.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.

As shown in accompanying drawing 1,2, asymmetric current source ground fault detection device described in the utility model, power acquisition AC220V, the optional common transformer that is used in is power supply or also configurable 10000:220(500VA) power taking PT to provide working power; This asymmetric current source ground fault detection device is primarily of three high-voltage wall bushings, three sampling module, Hi pilot, kernel control module, fault detector and GPRS communication module compositions; Sampling module forms primarily of electronics PT embedding and is directly connected with the three-phase high-voltage that wall bushing 1 is drawn, and the asymmetric current source of every platform has three wall bushings and three sampling modules; Three sampling modules are once held and are connected A respectively, B, C three-phase high-voltage, secondary terminals adopts star connection synthesis residual voltage (i.e. open delta voltage, low pressure has been changed into by a certain percentage compared with actual value), the residual voltage that kernel control module is sent here by detection sampling module is multiplied by the actual value that no-load voltage ratio can draw high-pressure side residual voltage again; When residual voltage value reaches certain numerical value, kernel control module controls Hi pilot and puts into operation thus create characteristic current signal, kernel control module control GPRS communication module is related data teletransmission simultaneously, and the fault detector hung on the line detects that namely this characteristic current signal thinks that circuit there occurs earth fault and provides warning message; Kernel control module 4 controls small wireless communication module and realizes short-range data and also carry out long-range data interaction by GPRS module alternately; Asymmetric current source will guarantee that rack ground connection is good when mounted, otherwise characteristic current signal does not have loop to transmit.

Below be only embody rule example of the present utility model, protection domain of the present utility model is not constituted any limitation; The technical scheme that all employing equivalents or equivalence are replaced and formed, all drops within the utility model rights protection scope.

Claims

1. asymmetric current source ground fault detection device, it is characterized in that: described pick-up unit is primarily of three high-voltage wall bushings, three sampling module, Hi pilot, kernel control module, fault detector and GPRS communication module compositions, described three sampling modules form primarily of electronics PT embedding respectively, the three-phase high-voltage circuit once holding connection three wall bushings respectively to draw of sampling module, the secondary terminals of three sampling modules is the residual voltage of star connection synthesis; Described fault detector hangs on the line; When residual voltage value reaches certain numerical value, kernel control module controls Hi pilot and produces characteristic current signal, the judgement of earth fault made by fault detector after this characteristic current signal being detected, kernel control module controls GPRS communication module by relevant information teletransmission simultaneously.

2. asymmetric current source ground fault detection device according to claim 1, is characterized in that: described Hi pilot adopts vacuum high-pressure contactor as high-voltage switch gear.