CN104360228A

CN104360228A - Method for improving positioning of fault section of power distribution network including distributed power supply through directional elements

Info

Publication number: CN104360228A
Application number: CN201410638664.0A
Authority: CN
Inventors: 杨国生; 郑涛; 王增平; 曹雅榕; 王燕萍; 朱时雨; 周泽昕; 王晓阳; 王文焕; 李伟
Original assignee: China Electric Power Research Institute Co Ltd CEPRI; North China Electric Power University
Current assignee: China Electric Power Research Institute Co Ltd CEPRI; North China Electric Power University
Priority date: 2014-11-07
Filing date: 2014-11-07
Publication date: 2015-02-18
Anticipated expiration: 2034-11-07
Also published as: CN104360228B

Abstract

The invention discloses a method for improving positioning of a fault section of a power distribution network including a distributed power supply through directional elements. The method comprises the steps that (1) after the power distribution network including the distributed power supply breaks down, whether a fault occurs in an area with a T joint or an area without a T joint is judged according to the direction of fault current reported by switches around a fault point; (2) if the direction information of the fault reported by the directional element on the side with the fault current supplied by a main power supply is in the positive direction, and the direction information of the fault reported by the directional element on the side with the fault current supplied by the distributed power supply is in the negative direction, it is accordingly judged that the fault occurs in the area with the T joint, and thus the fault isolation is conducted; (3) if the direction information of the fault current provided by feeder line switches around the fault point is identical, it is judged that the fault occurs in area without the T joint. The amplitude values of the fault current of the switches on the two sides of the fault point are different, the fault current crossing the switches on the same side of the fault point is approximately identical, and thus the specific area where the fault occurs can be judged and fault isolation can be conducted accordingly.

Description

Utilization orientation element improves the Fault Section Location of Distribution Network containing distributed power source

Technical field

The invention belongs to power system automation technology field, relate to the localization of fault of power distribution network, a kind of utilization orientation element improves the Fault Section Location of Distribution Network containing distributed power source specifically.

Background technology

Along with the fast development that the various novel renewable energy generating such as wind energy, sun power, biomass energy, ocean energy and underground heat is the distributed generation technology of representative, distributed power source is linked in power distribution network in a large number, corresponding change can be there is in trend distribution, short-circuit current situation during fault is also by great changes will take place, this proposes new requirement to system, especially, in localization of fault, this causes traditional electrical power distribution network fault location method no longer applicable.In order to correctly carry out the localization of fault of power distribution network when distributed power source accesses, new localization of fault scheme must be studied, impact localization of fault brought with the access eliminating distributed power source.

According to the feature of the short-circuit current that distributed power source provides, the present invention proposes a kind of localization of fault scheme, the power distribution network containing distributed power source can be made to find fault zone rapidly and accurately when breaking down, and fault zone is isolated, send repair personnel to carry out site disposal in time.This is to the power off time of the fault section that restores electricity, shortens and promote that the development and application of distributed power generation has very important meaning.

Summary of the invention

The object of the invention is to improve existing distribution network failure section location technology, propose a kind of containing distributed power source Fault Section Location of Distribution Network, when solving the distribution network failure containing distributed power source, the impact that the short-circuit current provided by distributed power source is located distribution network failure.

Technical scheme of the present invention is achieved in that a kind of utilization orientation element improves the Fault Section Location of Distribution Network containing distributed power source, it is characterized in that, comprises the following steps:

Step 1: after breaking down containing the power distribution network of distributed power source, according to the fault current direction that switch around trouble spot reports, the large regions (abbreviation fault zone) that failure judgement occurs is that T connects region or containing other regions that T connects;

Step 2: if provide the directional element reporting fault directional information of fault current side to be positive dirction by primary power, and provide the directional element reporting fault directional information of fault current side to be in the other direction by distributed power source, failure judgement occurs in T and connects region accordingly, thus isolated fault;

Step 3: if the fault current directional information that the feeder switch around trouble spot provides is identical, then failure judgement occurs in not containing other regions that T connects; Owing to providing the power supply flowing through both sides, trouble spot switch fault electric current different, then the fault current amplitudes of both sides, trouble spot switch experience is different, and the fault current size of the switch experience of side, trouble spot is similar to identical, the concrete section that fault occurs can be judged accordingly and carry out fault isolation;

Step 4: if failure judgement region is not containing other regions that T connects, under extreme case, the fault current of both sides, trouble spot switch experience may be identical, cannot determine concrete fault zone; Now, tripped by transformer station's wire-outgoing breaker overcurrent protection action, the DG after 2s on this feeder line all departs from from electrical network, overlaps, if transient fault, recover full feeder line and power after transformer station's wire-outgoing breaker tripping operation through 2.5 ~ 3.5s time delay; If permanent fault, then transformer station's wire-outgoing breaker trips again, and now the failure message at feeder switch place eliminates the impact of DG, can, according to fault current, rely on conventional failure locating rule carry out gamut localization of fault and carry out fault isolation.

Further, in described method, in step 1, the feeder switch place connect around region at T installs directional element additional, and specify that the short-circuit current direction provided by primary power is positive dirction, T connects the information that feeder switch that region non-faulty current flows through does not consider its directional element, only utilizes the directional information of other two feeder switches to judge.

Further, in described method, in step 2, if be that T connects region according to directional element failure judgement region, then this region is corresponding fault section; If fault occurs in not containing the region that T connects, then according to the concrete section that the size failure judgement of switch experience fault current each in this region occurs.

Further, in described method, in step 4, transformer station's wire-outgoing breaker possesses overcurrent protection and a high-speed reclosure function, and reclosing delay time is 2.5 ~ 3.5s; According to Q/GDW480-2010 regulation, the DG unintentionally knowing isolated island must depart from from electrical network in 2s after feeder fault.

The invention has the advantages that: (1) considers that fault current that distributed power source provides is on the impact of localization of fault, accurately locates the distribution network failure containing distributed power source; (2) utilize the existing failure message in each switch place to carry out localization of fault, reduce investment.

Accompanying drawing explanation

Figure 1A is that T connects area schematic.

Figure 1B is that T connects fault current directional diagram when region T2 breaks down.

Fig. 2 is other regions A6 do not connect containing T fault current directional diagram when breaking down.

In figure, dashed circle region T1, T2, T3, T4 are that T connects region, region A1, A2, A3 ... A13 is not containing other regions that T connects.S1 is transformer station's outlet switch, and D1, D2 are DG outlet switch, A, B, C ... S is feeder line block switch, and square represents isolating switch.Block switch B, C, L, E, F, O, P, Q, R, I, J and isolating switch D2 need install directional element additional, and K1, K2 are trouble spot mark, the current direction when direction of arrow is fault.

Embodiment

Below with reference to accompanying drawing and example, the present invention will be further described.

Embodiment 1

As shown in Figure 1B, K1 point is short-circuited fault, and position occurs and connects T2 region, region at T, fault current direction as shown in the figure.If feeder switch S1, A, B, C, D, E, D1, Q, P, O, D2, F, G, H, I place all collects fault and crosses stream information, because feeder switch E, F, O around T2 region are provided with directional element, feeder switch E place short-circuit current being thered is provided by primary power, is positive dirction fault current, feeder switch F, O place short-circuit current being thered is provided by DG, is reverse direction failure electric current, can judge that fault occurs in T2 region accordingly.

Embodiment 2

As shown in Figure 2, K2 point is short-circuited fault, position occurs not containing the A6 region, other regions that T connects.

Step 1: if feeder switch S1, A, B, C, D, E, D1, Q, P, O, F, G, D2, I, H all collect fault cross stream information, is now only out of order according to fault current walking direction and occurs in not containing other regions that T connects.

Step 2: the fault current amplitudes size that feeder switch C, D, E, F, G, H, the I in other regions do not connect containing T collect is compared, the fault current flowing through feeder switch F, G can be found flow through the fault current of feeder switch H, I and flow through the electric current of both sides, trouble spot feeder switch G, H and both differ by more than setting nargin (considering that the composition error that the progress of disease error of current transformer, the sampling of protection and the error of calculation are brought obtains), thus determine that fault section is the region A6 between feeder switch G, H, complete localization of fault.

Claims

1. utilization orientation element improves the Fault Section Location of Distribution Network containing distributed power source, it is characterized in that, comprises the following steps:

Step 1: after breaking down containing the power distribution network of distributed power source, according to the fault current direction that switch around trouble spot reports, the large regions that failure judgement occurs is that T connects region or containing other regions that T connects;

Step 2: if provide the directional element reporting fault directional information of fault current side to be positive dirction by primary power, and provide the directional element reporting fault directional information of fault current side to be in the other direction by distributed power source, failure judgement can occur in T and connect region accordingly, thus isolated fault;

Step 4: if failure judgement region is not containing other regions that T connects, under extreme case, the fault current of both sides, trouble spot switch experience may be identical, cannot determine concrete fault zone; Now, tripped by transformer station's wire-outgoing breaker overcurrent protection action, the DG after 2s on this feeder line all departs from from electrical network, overlaps, if transient fault, recover full feeder line and power after transformer station's wire-outgoing breaker tripping operation through 2.5 ~ 3.5s time delay; If permanent fault, then transformer station's wire-outgoing breaker trips again, and now the failure message at feeder switch place eliminates the impact of DG, according to fault current, relies on conventional failure locating rule carry out gamut localization of fault and carry out fault isolation.

2. method according to claim 1, it is characterized in that, in step 1, the feeder switch place connect around region at T installs directional element additional, and specify that the short-circuit current direction provided by primary power is positive dirction, T connects the information that feeder switch that region non-faulty current flows through does not consider its directional element, only utilizes the directional information of other two feeder switches to judge.

3. method according to claim 1, is characterized in that, in step 2, if be that T connects region according to directional element failure judgement region, then this region is corresponding fault section; If fault occurs in not containing the region that T connects, then according to the concrete section that the size failure judgement of switch experience fault current each in this region occurs.

4. method according to claim 1, is characterized in that, in step 4, transformer station's wire-outgoing breaker possesses overcurrent protection and a high-speed reclosure function, and reclosing delay time is 2.5 ~ 3.5s.