CN105226832A - A kind of relay protecting method - Google Patents

Abstract

The present invention proposes a kind of relay protecting method, be applied in the power distribution network containing distributed power source, comprise: step 100, with the Central Substations in region for Regional Control Center builds set of regions Chinese style protection system structure; Step 200, each protection for feed line intelligent terminal IED independent acquisition fault message in region also calculates, and fault message is converted into logical message, then to Regional Control Center upload logic information; Step 300, the logical message that each IED of Regional Control Center process uploads also obtains corresponding decision result, and then in region, each IED sends decision-making order, drive actions.Present invention achieves main backup protection integration and after preventing failure removal distributed power source do unplanned islet operation, enhance the reliability of protection system.

Description

A kind of relay protecting method

Technical field

The present invention relates to protecting electrical power system field, be specifically related to a kind of relay protecting method.

Background technology

21 century, facing mankind the double challenge of economy and social sustainable development.Economic and social development constantly, must have good environment and the permanent utilization of the energy to ensure.Some countries of the world, in order to tackle this situation, all propose and perform the policy and approaches of exploitation regenerative resource.Due to the day by day exhausted of fossil fuel and global warming problem, in addition utilize renewable energy power generation all fewer without consumption of fossil fuels, the waste gas waste water that discharges in power production process, therefore current research emphasis is become to the utilization of distributed power source (DistributedGeneration is called for short DG).

The main operational mode of world today's electric power system adopts centralized power generation, high pressure long distance power transmission and bulk power grid interconnected.But along with the diversified power demands of user and more and more higher secure safety requirement, sometimes high pressure remote conveying electric system seems very clumsy and fragile.Such as, in typical interconnected electric power system, Local Accidents very easily spreads, and affects greatly whole electrical network, may cause large-area power-cuts or even Tie-line Opening time serious; Bulk power grid can not the change of tracking system electric load flexibly, cause power generating equipment utilance low, and then whole economic benefit is not ideal enough; The development of bulk power grid simultaneously also can cause serious environmental issue.Adopt distributed power generation power supply technique, contribute to making full use of the abundant clean and regenerative resource in various places, the strategy of China's the Implement of sustainable development is of great immediate significance.The main feature of distributed power generation is the production of electric power and is used in same place or is limited in regional area, can realize economy, efficiently, reliably generate electricity.It can delay to need to increase due to the growth of load builds or the facility of electric power system of dilatation.Can reduce or avoid the investment on transmission and distribution network; Can for providing sub-load between user, particularly can to reduce at peak load total electricity charge that user needs to pay period, and can for user provide urgent or back-up source with the reliability improving power distribution network and power and security and stability.In a word, distributed power generation effectively can be configured in loading zone, increases the stability of power distribution network, improves distribution network voltage and load power factor, the renewal speed delaying system, increase electric network reliability and economy.Distributed power generation, because having the advantage of its uniqueness, supplements progressively becoming the strong of following bulk power grid and supports.At present, the much energy in the world, electric power expert think that bulk power grid and distributed power generation combine and can improve power system reliability and flexibility, and can reduce investment outlay again simultaneously, reduce the wastage, be the direction of 21 century electric power industry development.Like this for solution energy-conserving and environment-protective, investment, electric power safety, meet users on diversity and play an important role.

While the advantage of distributed power generation is very outstanding, it also serves new problem and challenge for electric power system band, and such as, distributed unit power supply rate for incorporation into the power network is higher, it is very difficult etc. to control it.The access of distributed power source makes traditional single supply radial distribution networks become the multi-power system that spreads all over power supply and load; change the radial structure of power distribution network; change the trend size and Orientation of distribution, a series of impact is created on the operation of system and protection.

The grid-connected grid structure for the planning of distribution network system, the prediction of electric load and electrical network of distributed power source, the quality of power supply bring greater impact:

(1) the non-one-way of trend

Traditional distribution network system is generally a single supply network, and its topological structure is generally radial, and the direction of trend flows to load side by system side.When after distributed power source access distribution network system, it just becomes a power network, and the direction of trend is no longer just unidirectional, and now the direction of tide of system exists reverse possibility.On the one hand, in some cases (as distribution network system when underloading or distributed power source permeability high), may there is imbalance in overall system supply and demand, and then occur the phenomenon that trend is reverse, and this proposes new requirement and challenge to traditional relaying protection; On the other hand; when the equilibrium of supply and demand that system is total; but because regenerative resource exists intermittent feature; it relies on very strong to weather and region; so exerting oneself of it is difficult to prediction; in this case, situation reverse during forward when trend also likely appears in distribution network system local, now just needs a kind of new Preservation tactics.

(2) mistake action and rejecting action protected

Before distributed power source connecting system, system load flow is unidirectional, and fault current is from system power supply effluent to fault point, and generally line impedance is the principal element affecting fault current.And after accessing distributed power source, during the system failure, be equivalent to introduce extra fault current source, there is potential bi-directional failure electric current.When distributed power source injects short circuit current to fault point, the fault curre that main feeder protection detects just may reduce, thus lowers the sensitivity of protection.Meanwhile, because distributed power source provides the situation of fault current to exist to fault point, thus the size and Orientation of fault current that influential system protection detects, cause relevant protection to there is the possibility of mistake action and rejecting action.

(3) automatic reclosing

Why reclosing technology is widely used in distribution network system, is because the fault of 80% is transient fault in distribution network systems.But after the access of distributed power source, two aspect impacts and challenge are just brought on reclosing technology.Cause the reason of unsuccessful reclosing to mainly contain two, one when being due to system jam, and distributed power source extends the time of going to dissociate in fault point to the short circuit current that short dot provides, allow multiple action time arc reignition, cause unsuccessful reclosing; Another is the requirement owing to not meeting accurate synchronous recloser between system power supply and distributed power source, there will be the problem of non-Switching Synchronization, causes unsuccessful reclosing, even especially can produce DG distribution network system and impact and destroy.

(4) distance protection

So-called distance protection be exactly fault point within protection range time, namely measurement impedance is less than protection act when adjusting impedance.Therefore distance protection is for owing amount protection, also referred to as impedance protection, is actually the size of the impedance between measuring and protecting installation place to fault point.The voltage generally responded to by impedance relay and maximum fault current can determine protection range; but the size of the electric current and voltage value that impedance relay is responded to can be changed after distributed power source access; so have an impact to protection range, and then make the malfunction of distance protection possibility.

(5) isolated island and anti-islanding protection

When breaking down in distributed power source upstream, system power supply is due to fault or other reasons disconnection, and distributed power source is powered to components of system as directed based model for load duration, and system will there will be islet operation.System is do not allow islet operation in the ordinary course of things, therefore must take feasible Preservation tactics and measure to this situation, Here it is so-called island protect.Anti-islanding protection refers to prevent islet operation, avoids the Preservation tactics and the measure that cause equipment and life safety therefrom.

Summary of the invention

Problem existing at least part of solution prior art, the present invention proposes a kind of relay protecting method, is applied in the power distribution network containing distributed power source, comprises:

Step 100, with the Central Substations in region for Regional Control Center builds set of regions Chinese style protection system structure;

Step 200, each protection for feed line intelligent terminal IED independent acquisition fault message in region also calculates, and fault message is converted into logical message, then to Regional Control Center upload logic information;

Step 300, the logical message that each IED of Regional Control Center process uploads also obtains corresponding decision result, and then in region, each IED sends decision-making order, drive actions.

Wherein, circuit breaker has all been installed at each line outlet place of power distribution network, and the protection of distributed power source upstream grid side is all that tool is directive.

Wherein, after line failure, the distributed I ED that each line port place installs carries out fault detect, if detect, fault occurs, then transmit digital signal 1, i.e. fault-signal to Regional Control Center; Regional Control Center collects the information that in protection zone, each IED sends, and judges fault element, sends action message subsequently to relevant IED, drives circuit breaker trip, thus realizes main backup protection integration.

Wherein, utilized stream information to carry out fault detect; I _jrepresent the detection signal of IED, having during fault current is 1, otherwise is 0, I _jthe fault current collected by a jth IED and current setting compare and obtain:

Wherein, the fault-signal that in Regional Control Center collecting zone, each IED sends, sets up fault message matrix, and whether fault message matrix conversion zone inner breaker has the situation flowing through fault current.

Wherein, the process of failure judgement element comprises:

1) the power distribution network network topology structure matrix T in region is built;

Each killer switch in region is used as a node process, and they are numbered successively, generate the network topology structure matrix T in fault zone, for the fault zone having n node by Regional Control Center, its T matrix is the square formation of n*n, and T matrix element is:

2) fault message matrix F is built;

After F matrix reaction fault occurs, the fault message that IED detects, F is the line order row of 1*n, element f _ifor:

3) revise fault message matrix F obtain matrix F ';

When revising this line fault in F matrix, the fault-signal that adjacent lines switch sends, makes its element corresponding in revised F ' matrix be 0;

4) obtaining fault element recognition matrix is:

P＝T×F ^′T

Identify fault element according to matrix P, the result for element each in matrix P does description below: P _iwhen=0, represent that this circuit breaker place circuit does not have fault; P _iwhen=1, represent this circuit breaker place line failure; P _iwhen=2, represent that the adjacent lines of this circuit breaker place circuit breaks down, wherein, P _iin representing matrix P each element of the i-th row and.

Wherein, Regional Control Center, according to the information of fault element recognition matrix P each IED transfer control signal in region, drives place unit breaker tripping operation: P _iwhen=0, not to corresponding IED move instruction, IED place unit breaker does not take any action yet; P _iwhen=1, transmit trip command to corresponding IED, IED drives place unit breaker instantaneous tripping; P _iwhen=2, transmit trip command to corresponding IED, IED drives place unit breaker time delay Δ t tripping operation.

Wherein, described region and Regional Control Center is obtained by the following method:

The direction of definition from system power supply toward line end is positive direction, and system power supply side is upstream, and line end is downstream, take bus as node, and branch road is that limit formation s × s matrix D describes network configuration:

$D=\left[\begin{array}{cccc}{d}_{11}& d_{12}& ...& d_{1s}\\ d_{21}& d_{22}& ...& d_{2s}\\ .& .& & .\\ .& .& & .\\ .& .& & .\\ d_{31}& d_{32}& ...& d_{ss}\end{array}\right]$

Wherein: between node i, j, there is d when branch road connects _ij=1, i ≠ j; Node i be multiple-limb or three branch nodes time d _ii=1, multiple-limb refers to the situation being greater than three branches; All the other matrix elements are zero, s is the node total number comprised in power distribution network;

Retain the element of diagonal side, opposite side element resets, to reduce storage and the amount of calculation of data;

Traverses network node, the set of node of search formation in units of region and the linking relationship of node, described region meets the following conditions:

(1) boundary node in region is multiple-limb or three branch nodes;

(2) region is the set of node that the set of node that comprises of branch road that two multiple-limbs or three branch nodes are determined or edge three branch node downstream leg comprise;

After Region dividing completes, the arbitrary IED in random appointed area is as the Regional Control Center in this region.

When dropping into when there being distributed power source DG or excise, repair described region: if node excision DG, and point number < 3, by the region merging technique of node headed by this node to the region being end-node with this node; If node drops into DG, then origin node region is divided into two using this node as the first node of region end-node and region.

Present invention achieves main backup protection integration and after preventing failure removal distributed power source do unplanned islet operation, enhance the reliability of protection system.

Accompanying drawing explanation

Fig. 1 is the flow chart of a kind of relay protecting method that the present invention proposes.

Embodiment

Below in conjunction with accompanying drawing of the present invention, technical scheme of the present invention is clearly and completely described.Here will be described exemplary embodiment in detail, its sample table shows in the accompanying drawings.When description below relates to accompanying drawing, unless otherwise indicated, the same numbers in different accompanying drawing represents same or analogous key element.Execution mode described in following exemplary embodiment does not represent all execution modes consistent with the present invention.On the contrary, they only with as in appended claims describe in detail, the example of apparatus and method that aspects more of the present invention are consistent.

See Fig. 1, a kind of relay protecting method that the present invention proposes, is applied in the power distribution network containing distributed power source, comprises:

Step 100, with the Central Substations in region for Regional Control Center builds set of regions Chinese style protection system structure;

Power distribution network in single supply radial pattern structure, provides electric energy by bulk power grid is single-ended usually; , between region, generally there is not complicated which couple relation in district management.Distribution network communication system also builds based on its network structure feature, usually, can there is an important transformer station, carry out global monitoring as center to affiliated area power distribution network in a certain region.

Step 200, each protection for feed line intelligent terminal IED independent acquisition fault message in region also calculates, and fault message is converted into logical message, then to Regional Control Center upload logic information;

Step 300, the logical message that Regional Control Center is uploaded according to each IED of fault element recognizer process also obtains corresponding decision result, and then in region, each IED sends decision-making order, drive actions.

On the one hand, make full use of the advantage of centralized protection system structure, conveniently realize main backup protection integration; On the other hand, the factor of synthesise various, conservative control region scale, optimization information gathering, to reduce the burden to control centre, ensure that control centre can safe and stable operation.

Wherein, circuit breaker has all been installed at each line outlet place of power distribution network, and the protection of distributed power source upstream grid side is all that tool is directive.

After line failure, the distributed I ED that each line port place installs carries out fault detect, if detect, fault occurs, then transmit digital signal 1, i.e. fault-signal to Regional Control Center; Regional Control Center collects the information that in protection zone, each IED sends, and utilizes fault element recognizer to judge fault element, sends action message subsequently to relevant IED, drives circuit breaker trip, thus realizes main backup protection integration.

Distribution feeder does not generally install PT, usually utilizes the current information in current transformer measurement circuitry, therefore, study the method carrying out detection failure based on fault current information and have important practical value, the present invention utilized stream information to carry out fault detect.

I _jrepresent the detection signal of IED, having during fault current is that 1 (for meeting selectivity requirement, some protection also requires to have directivity; therefore when these IED only detect forward fault current; detection signal is just 1, comes detection failure direction by increasing PT element), otherwise be 0.For the detection method crossing stream information, the fault current that can be collected by a jth IED and current setting compare and obtain:

Because only need reaction to have fault current to flow through, do not require the cooperation of current setting between element, so size only need by hide normal operation time overload electric current adjust.Branch road is connected for non-distributed power source, said method can increase the sensitivity of fault detect on the one hand, " polymorphism " problem that after effectively can solving distributed power source access on the other hand, fault current presents, because be adjust by escaping load current, so during fault, even if distributed power source does not provide short circuit current to fault point, the fault current that bulk power grid provides also enough ensures the sensitivity of overcurrent infomation detection.

The fault-signal that in control centre's collecting zone, each IED sends, sets up fault message matrix.Whether fault message matrix conversion zone inner breaker has the situation flowing through fault current.

Concrete Fault Identification algorithm is:

1) the power distribution network network topology structure matrix T in region is built.Each killer switch in region is used as a node process, and they are numbered successively.On this basis, the network topology structure matrix T in fault zone is generated by decision-making main frame.For the fault zone having n node, its T matrix is the square formation of n*n, and the generation principle of T matrix element is:

2) fault message matrix F is built.After F matrix key reaction fault occurs, the fault message that IED detects.Regulation F is the line order row of 1*n, element f _igeneration principle be:

3) revise fault message matrix F obtain matrix F ';

When revising this line fault in F matrix, the fault-signal that adjacent lines switch sends, makes its element corresponding in revised F ' matrix be 0;

4) obtaining fault element recognition matrix is:

P＝T×F ^′T

Identify fault element according to matrix P, the result for element each in matrix P does description below: P _iwhen=0, represent that this circuit breaker place circuit does not have fault; P _iwhen=1, represent this circuit breaker place line failure; P _iwhen=2, represent that the adjacent lines of this circuit breaker place circuit breaks down, wherein, P _iin representing matrix P each element of the i-th row and.

Control centre, according to the information of fault element recognition matrix P each IED transfer control signal in region, drives place unit breaker tripping operation: P _iwhen=0, not to corresponding IED move instruction, IED place unit breaker does not take any action yet; P _iwhen=1, transmit trip command to corresponding IED, IED drives place unit breaker instantaneous tripping; P _iwhen=2, transmit trip command to corresponding IED, IED drives place unit breaker time delay Δ t tripping operation.This trip protection scheme can realize main backup protection integration and prevent distributed power source from after failure removal, doing unplanned islet operation.Δ t can set according to actual conditions.

With regard to protection, the scope accepting fault message is not the bigger the better, mainly for two reasons: 1. receive and process the rapidity requirement that large-scale information not easily meets protection; 2. fault may only have an impact to subrange, and the fault message of this scope is most important for breakdown judge, and this scope is then unimportant with external information.In practical application, exchange message can increase communication system burden undoubtedly on a large scale blindly, reduces the reliability of communication system, also meaningless for protection system.Each IED is quickly and reliably worked, the information exchange scope of IED must be specified, by the IED information exchange localizing faults in certain area during fault.Be described to the division of IED associated region (hereinafter referred associated region) below.So that above-mentioned to the present invention is that the scheme of regional center further improves with Central Substations.

Analyze a distribution network, first will set up each internodal topological relation according to network of relation data.The direction of the present invention's definition from system power supply toward line end is positive direction, and system power supply side is upstream, and line end is downstream.Take bus as node, branch road is that limit formation s × s matrix D describes network configuration (specify that same downstream branch node serial number is greater than upstream node, to establish unique traversal direction, that avoids associated region repeats division):

$D=\left[\begin{array}{cccc}{d}_{11}& d_{12}& ...& d_{1s}\\ d_{21}& d_{22}& ...& d_{2s}\\ .& .& & .\\ .& .& & .\\ .& .& & .\\ d_{31}& d_{32}& ...& d_{ss}\end{array}\right]$

Wherein: between node i, j, there is d when branch road connects _ij=1 (i ≠ j); Node i be multiple-limb or three branch nodes time d _ii=1; All the other matrix elements are zero, s is the node total number comprised in power distribution network, and multiple-limb refers to the situation being greater than three branches.

Defined from matrix element, matrix D is symmetrical matrix, therefore only need retain the element of diagonal side, and opposite side element can reset, to reduce storage and the amount of calculation of data.

Network description matrix only specifies node type and correlation thereof, and associated region division needs traverses network node, search forms the linking relationship of set of node (IED collection) in units of region and node, reach the region after division when fault should be able to fast, the object that whether breaks down of inside, judging area independently.Provide two division principles thus:

1) associated region boundary node is necessary can failure judgement direction.

2) associated region should be little as far as possible, to reduce the information exchange scope of IED, reduces network service burden.

On principle 1, the boundary node of associated region must be multiple-limb or three branch nodes.On principle 2, under normal circumstances, associated region should be the set of node that the set of node that comprises of branch road that two multiple-limbs or three branch nodes are determined or edge three branch node downstream leg comprise.

After Region dividing completes, the arbitrary IED in random appointed area is as the Regional Control Center in this region.

DG switching can cause node to connect a point number and change, thus may concept transfer character: node is from can becoming and can not judge (DG excision) or can not become and can judge (DG input) in failure judgement direction in failure judgement direction.For this situation, provide the method for trimming of associated region: if node DG excises, and point number < 3, by the region merging technique of node headed by this node to the region being end-node with this node; If node drops into DG, then origin node region is divided into two using this node as the first node of region end-node and region.

Distributing protection system carries out decision-making by the intelligent protection terminal (IntelligentElectronicDeviceIED) of each dispersion; from the angle of communication network technology; be peer-to-peer communication network; in network, unit can initiatively initiating communication; can communicate mutually at any time between them, obtain the information needed.Under this kind of pattern, the formulation of the collection of each IED equipment complete independently fault message, process and Preservation tactics and action executing, each protection terminal utilizes the information in certain limit, based on algorithm and criterion, realizes reliable defencive function.This kind of structure reduces the dependence of independent IED, and the situation even if certain protection terminal breaks down, contiguous protection terminal can be used as its standby and completes protection work.But the performance of distributed structure to protection terminal equipment IED has had higher requirement; And along with the increase of IED quantity, easily cause the communication logic between IED numerous and diverse, the Maintenance and Repair workload difficulty of communication apparatus.In addition, consider from the reliability of relaying protection, in distributed system structure, realize main backup protection integration relative complex.Centralized protection system carries out decision-making by control centre; from the angle of communication network technology; be master slave communication network; in this network, the information such as collected electric current, voltage, fault direction are uploaded to control centre by communication system from the measuring component unit by each after simple computing; control centre is according to the topology information of the information uploaded and electrical network; combination algorithm; identify fault element; and then formulate trip protection strategy, and decision instruction is sent to corresponding execution terminal.Control centre has quick, high performance data-handling capacity, and centralized decision-making can accomplish system area-wide optimal control, more can embody the advantage of wide area protection.In addition, the protection scheme realizing main backup protection integration in integrated system structure is relatively simple.But centralized configuration is higher to control centre's equipment requirement, focusing on of bulk information makes control centre's amount of calculation large, therefore needs the collection of reasonably optimizing amount of information, reduces information scale.Originally the present invention is based on the distinctive design feature of power distribution network and build set of regions Chinese style system configuration, the advantage of abundant absorb set Chinese style system configuration, optimizes information gathering simultaneously, reduces the pressure of control centre as far as possible.

Those skilled in the art, at consideration specification and after putting into practice invention disclosed herein, will easily expect other embodiment of the present invention.The application is intended to contain any modification of the present invention, purposes or adaptations, and these modification, purposes or adaptations are followed general principle of the present invention and comprised the undocumented common practise in the art of the present invention or conventional techniques means.

Should be understood that, the present invention is not limited to precision architecture described above and illustrated in the accompanying drawings, and can carry out various amendment and change not departing from its scope.Scope of the present invention is only limited by appended claim.

Claims (9)

1. a relay protecting method, is applied in the power distribution network containing distributed power source, comprises:

Step 100, with the Central Substations in region for Regional Control Center builds set of regions Chinese style protection system structure;

Step 200, each protection for feed line intelligent terminal IED independent acquisition fault message in region also calculates, and fault message is converted into logical message, then to Regional Control Center upload logic information;

Step 300, the logical message that each IED of Regional Control Center process uploads also obtains corresponding decision result, and then in region, each IED sends decision-making order, drive actions.

2. relay protecting method as claimed in claim 1, wherein, circuit breaker has all been installed at each line outlet place of power distribution network, and the protection of distributed power source upstream grid side is all that tool is directive.

3. relay protecting method as claimed in claim 2, wherein, after line failure, the distributed I ED that each line port place installs carries out fault detect, if detect, fault occurs, then transmit digital signal 1, i.e. fault-signal to Regional Control Center; Regional Control Center collects the information that in protection zone, each IED sends, and judges fault element, sends action message subsequently to relevant IED, drives circuit breaker trip, thus realizes main backup protection integration.

4. relay protecting method as claimed in claim 3, wherein, utilized stream information to carry out fault detect; I _jrepresent the detection signal of IED, having during fault current is 1, otherwise is 0, I _jthe fault current collected by a jth IED and current setting compare and obtain:

5. relay protecting method as claimed in claim 4, wherein, the fault-signal that in Regional Control Center collecting zone, each IED sends, sets up fault message matrix, and whether fault message matrix conversion zone inner breaker has the situation flowing through fault current.

6. relay protecting method as claimed in claim 3, wherein, the process of failure judgement element comprises:

1) the power distribution network network topology structure matrix T in region is built;

Each killer switch in region is used as a node process, and they are numbered successively, generate the network topology structure matrix T in fault zone, for the fault zone having n node by Regional Control Center, its T matrix is the square formation of n*n, and T matrix element is:

2) fault message matrix F is built;

After F matrix reaction fault occurs, the fault message that IED detects, F is the line order row of 1*n, element f _ifor:

3) revise fault message matrix F obtain matrix F ';

When revising this line fault in F matrix, the fault-signal that adjacent lines switch sends, makes its element corresponding in revised F ' matrix be 0;

4) obtaining fault element recognition matrix is:

P＝T×F ^′T

Identify fault element according to matrix P, the result for element each in matrix P does description below: P _iwhen=0, represent that this circuit breaker place circuit does not have fault; P _iwhen=1, represent this circuit breaker place line failure; P _iwhen=2, represent that the adjacent lines of this circuit breaker place circuit breaks down, wherein, P _iin representing matrix P each element of the i-th row and.

7. relay protecting method as claimed in claim 6, wherein, Regional Control Center, according to the information of fault element recognition matrix P each IED transfer control signal in region, drives place unit breaker tripping operation: P _iwhen=0, not to corresponding IED move instruction, IED place unit breaker does not take any action yet; P _iwhen=1, transmit trip command to corresponding IED, IED drives place unit breaker instantaneous tripping; P _iwhen=2, transmit trip command to corresponding IED, IED drives place unit breaker time delay Δ t tripping operation.

8. relay protecting method as claimed in claim 1, wherein, obtains described region and Regional Control Center by the following method:

The direction of definition from system power supply toward line end is positive direction, and system power supply side is upstream, and line end is downstream, take bus as node, and branch road is that limit formation s × s matrix D describes network configuration:

$D=\left[\begin{array}{cccc}{d}_{11}& d_{12}& ...& d_{1s}\\ d_{21}& d_{22}& ...& d_{2s}\\ .& .& & .\\ .& .& & .\\ .& .& & .\\ d_{31}& d_{32}& ...& d_{ss}\end{array}\right]$

Wherein: between node i, j, there is d when branch road connects _ij=1, i ≠ j; Node i be multiple-limb or three branch nodes time d _ii=1, multiple-limb refers to the situation being greater than three branches; All the other matrix elements are zero, s is the node total number comprised in power distribution network;

Retain the element of diagonal side, opposite side element resets, to reduce storage and the amount of calculation of data;

Traverses network node, the set of node of search formation in units of region and the linking relationship of node, described region meets the following conditions:

(1) boundary node in region is multiple-limb or three branch nodes;

(2) region is the set of node that the set of node that comprises of branch road that two multiple-limbs or three branch nodes are determined or edge three branch node downstream leg comprise;

After Region dividing completes, the arbitrary IED in random appointed area is as the Regional Control Center in this region.

9. relay protecting method as claimed in claim 8, wherein,

When dropping into when there being distributed power source DG or excise, repair described region: if node excision DG, and point number < 3, by the region merging technique of node headed by this node to the region being end-node with this node; If node drops into DG, then origin node region is divided into two using this node as the first node of region end-node and region.