CN104485736A - Intelligent protection center-based wide-area backup protection system and method - Google Patents

Abstract

The invention relates to an intelligent protection center-based wide-area backup protection system and method. The system comprises a GOOSE network for acquiring switching quantities of a plurality of substations, a sampling value network for acquiring electrical quantities of the substations, relaying protection units connected with the GOOSE network and the sampling value network and a protection intelligent center connected with the relaying protection units through a wide area network; the system further comprises merging units which are connected with mutual inductors of the substations; the merging units merge the electrical quantities measured by the mutual inductors and performs synchronization processing on the electrical quantities, and transmit the processed electrical quantities to the relaying protection units through the sampling value network; the switching quantities of the substations are transmitted to the relaying protection units through the GOOSE network; the relaying protection units calculate the direction of a fault through the obtained electric quantities, and transmit the received switching quantities and the direction of the fault which is obtained through calculation to the protection intelligent center through the wide area network; and the protection intelligent center determines the position of the fault and issues a tripping instruction. The intelligent protection center-based wide-area backup protection system and method of the invention are unrelated to the structures of power grids and the types of faults, and have the advantages of high movement speed, high reliability and strong adaptability.

Description

Based on the wide area backup protection system and method for protection intelligent centre

Technical field

The present invention relates to technical field of power systems, be specifically related to a kind of wide area backup protection system and method based on protection intelligent centre.

Background technology

1997; the concept of wide area protection is proposed in " Wide AreasProtection Against Voltage Collapse " literary composition that Sweden scholar Bertillngelesso delivers on IEEE first; be used for preventing the term Voltage of interconnected network to collapse; have a power failure on a large scale in the U.S. in 1996, summer in 2003 U.S.A add after interconnected network collapse accident occurs in succession, people recognize the cooperation should strengthening between relaying protection and safety device from the angle of entirety.Along with the development that national intelligent grid is built, the access of distributed power source, each large regions electrical network is interconnected gradually, electric network composition more sophisticated, and the selectivity to relaying protection, reliability, sensitivity and quick-action are proposed higher requirement by the self-healing property feature of electrical network.And traditional backup protection is mainly by form based on the stage distance protection of one-terminal data or zero-sequencedirectional protection, the running status that in the just system of reaction, certain is put or regional area is limited, lack cooperation each other, after cannot solving equipment excision, trend shifts the impact caused on a large scale, and traditional backup protection ensures selectivity by the cooperation in definite value and time limit, so along with the change of electric network composition and operational mode, there is difficulty of adjusting, action delay is long, fault incidence is large, the defects such as load-bearing capacity of hiding difference, even there is protection mismatch or under-sensitive situation.Therefore, wide area protection receives the concern of more scholars.

Along with the develop rapidly of computer processing technology and the communication technology; Ethernet just progressively replaces the fieldbus of Industry Control; the transformer station's local area network (LAN) based on Ethernet has been set up in transformer station; many high voltage substations have also laid SDH optical fiber ring network; each transformer station local area network (LAN) is coupled together and forms electrical power system wide-area net; the performance of the wide area communications sytem of phasor measurement unit (PMU), WAMS (WAMS) has been enough to the standard meeting relaying protection, for the engineer applied of wide area protection is had laid a good foundation.

At present; scholars are to the still clearly ununified definition of wide area protection; but by the analysis to its feature and effect; the concept of wide area protection can be summarized as follows: the protective device in electric power system is passed through fiber interconnect; obtain multipoint fault information; according to network topology structure; algorithms of different is utilized to carry out fault location; thus excise fault fast, reliably, accurately; and the impact on system safety stable operation after analysis of failure excision, take corresponding strategy to guarantee the safe operation of electric power system.

And the protective value comparatively perfect of existing main protection very high to main protection rapidity requirement due to the element in electric power system, wide area protection then needs to be realized by multiple spot information interaction and concentrated judgement, so mainly bear the task of electric power system backup protection.

Run in code of adjusting at 220 ~ 500kv grid relay protective apparatus and specify; in order to ensure the stability of relay protection of power system; all operational outfit (circuits; bus; transformer) all must be separate by two cover AC and DC input and output loops, and the protective relaying device controlling different circuit breaker is respectively protected.For the bus of more than 220kv, the backup protection of bus protection is served as in the backup protection of transformer or circuit.Circuit for more than 220kv generally adopts nearly backup protection mode; namely when a set of protective relaying device tripping of fault element; fault is excised by separate another set of protection act; and when circuit breaker tripping; starting circuit breaker failure protection, disconnect with fault element access the every other circuit breaker being connected power supply that bus is connected.Backup protection mode far away can be adopted when having ready conditions, when the protective device namely corresponding to fault element or circuit breaker tripping, excise fault by the upper level protective relaying device action of the most contiguous fault element of mains side.

Summary of the invention

In order to solve above-mentioned problems of the prior art; order of the present invention is to provide a kind of wide area backup protection system and method based on protection intelligent centre, can provide backup protection to force devices all in wide area network, particularly realizes the near fast backup protection of interconnection between station; have nothing to do with the concrete structure of electrical network; and be insensitive to fault type, transition resistance, fault initial angle and power configuration; quick action; reliability is high, and structure is simple, and adaptivity is strong.

For achieving the above object, the technical solution adopted in the present invention is:

Based on the wide area backup protection system of protection intelligent centre, comprise the GOOSE net gathering multiple transformer substation switch amount, gather the sampled value network of transformer station's electric parameters, the Relay Protection Unit be connected with GOOSE net and sampled value network, the protection intelligent centre be connected by wide area network with Relay Protection Unit, also comprise the merge cells be connected with voltage transformer with the current transformer of transformer station, the electric parameters of current transformer and voltage measuring transformer is carried out merging and synchronous process by described merge cells, and the digital electric amount after process is sent to Relay Protection Unit by sampled value network, the switching value of transformer station sends to Relay Protection Unit by GOOSE net, Relay Protection Unit calculates fault direction by gained electrical quantity, then the switching value received and the fault direction calculated are passed to protection intelligent centre by wide area network, to be out of order position issue trip signal by protection intelligent centre decision-making.

Described Relay Protection Unit comprises the fault detection module, signal processing module and the abort situation discrimination module that are connected successively with merge cells in transformer station; also comprise the communication module communicated to connect with signal processing module and abort situation discrimination module; the tripping operation decision-making module be connected with abort situation discrimination module, described tripping operation decision-making module is connected with the circuit breaker in transformer station.

Described protection intelligent centre only collects the fault message processed through each transformer station, the voltage and current value not in the outlet of each transformer station.

Above-mentioned protection system carries out the method for wide area backup protection, the electric parameters of current transformer and voltage transformer transmission is carried out merging with synchronous process and by sampled value network delivery to fault detection module by described merge cells, according to the electric parameters after process, fault detection module has judged whether that fault occurs, if there is fault to occur, then fault message is passed to signal processing module, fault direction is calculated by signal processing module, fault direction is passed to abort situation discrimination module, the decision-making of abort situation discrimination module is out of order position of components, then fault element position is passed to tripping operation decision-making module, the circuit breaker that tripping operation decision-making module tripping transformer station internal fault element is corresponding, the abort situation of the fault direction information that signal processing module calculates by described communication module and decision-making place of abort situation discrimination module passes to protection intelligent centre by wide area network, to be out of order position by fault location algorithm decision-making by protection intelligent centre, as the redundancy protecting of Relay Protection Unit in transformer station.

Described fault location algorithm comprises the steps:

Step 1: protection intelligent centre collects the state of wide area protection scope inner breaker by wide area network, determine the network topology structure of electric power system to be protected, thus form bus-circuit incidence matrices, the row corresponding substation bus bar respectively of this incidence matrices, row are corresponding substation bus bar interconnection respectively, element is corresponding circuit breaker numbering, if substation bus bar interconnection is not directly connected with substation bus bar, then inserts element 0;

Step 2: in protection intelligent centre statistics bus-circuit incidence matrices, each row nonzero element number sum is designated as N _i, wherein i is line number, and by N _ibe stored in protection intelligent centre; After fault occurs; in each transformer station, Relay Protection Unit uploads fault direction information to protection intelligent centre; according to fault direction logical message, bus-circuit association status matrix is obtained to the bus-each row of circuit incidence matrices each row enlogy value, then draw the fault eigenvalue A of each substation bus bar interconnection within the scope of wide area protection by row summation respectively _i, summation draws the fault eigenvalue B of each substation bus bar within the scope of wide area protection by row _i, by A _iand B _irespectively with 2 and-N _icompare; determine fault occurrence positions; if the fault occurrence positions judged is substation bus bar interconnection; in bus-circuit incidence matrices, then search for the circuit breaker numbering of the row correspondence at fault substation bus bar interconnection place; and this circuit breaker of time delay tripping; if the fault occurrence positions judged is substation bus bar; in bus-circuit incidence matrices, then search for the circuit breaker numbering that the row at fault substation bus bar place is corresponding; and this circuit breaker of time delay tripping, realize the near fast backup protection without adjusting.

Compared to the prior art, tool of the present invention has the following advantages:

1, no longer only for single system element; but utilize multiple spot information in electric power system; backup protection is provided to all elements in certain area; thus the complicated tuning process avoided in protective relaying device time definite value, and there is good adaptivity for electric power system different running method.

2, protect intelligent centre only to collect the fault message processed through each transformer station, and there is not information interaction between each transformer station, reduce the of ac of information in electric power system.

Accompanying drawing explanation

Fig. 1 is protection system structure chart of the present invention.

Fig. 2 is protection system application schematic diagram of the present invention.

Fig. 3 is Relay Protection Unit structure chart.

Fig. 4 is fault location algorithm flow chart.

Fig. 5 is k1 point short-circuit structure figure in the embodiment of the present invention.

Fig. 6 is k2 point short-circuit structure figure in the embodiment of the present invention.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.

As depicted in figs. 1 and 2, the present invention is based on the wide area backup protection system of protection intelligent centre, comprise the GOOSE net gathering multiple transformer substation switch amount, gather the sampled value network of transformer station's electric parameters, the Relay Protection Unit be connected with GOOSE net and sampled value network, the protection intelligent centre be connected by wide area network with Relay Protection Unit, also comprise the merge cells be connected with voltage transformer with the current transformer of transformer station, the electric parameters of current transformer and voltage measuring transformer is carried out merging and synchronous process by described merge cells, and the digital electric amount after process is sent to Relay Protection Unit by sampled value network, the switching value of transformer station sends to Relay Protection Unit by GOOSE net, Relay Protection Unit calculates fault direction by gained electrical quantity, then the switching value received and the fault direction calculated are passed to protection intelligent centre by wide area network, to be out of order position issue trip signal by protection intelligent centre decision-making.

Below each unit of present system is described in detail:

Merge cells (Merging Unit; MU) be define first in IEC60044-8 for being connected with the electronic mutual inductor of Digital output; its function is used to carry out merging and synchronous process to the electric parameters that instrument transformer transmits, and the digital signal after process is forwarded according to specific form and give protection, measuring and controlling equipment.The interface of merge cells and secondary device is the unidirectional multichannel point to point connect of serial; it is by 7 (3 measurements; 3 protections; 1 is for subsequent use) more than current transformer and 5 (3 measurements, protections; 1 bus; 1 is for subsequent use) more than voltage transformer merge into a unit group, then by export instantaneous digital signal be filled in same Frame.Its implementation procedure is: receiving station's end synchronised clock input signal, then to high-pressure side, each road A/D sends synchronous switching signal, carries out conversion process, pass to secondary device finally by Ethernet card interface to the data that high-pressure side gathers.

Wide area network is as the visual plant of communication of digitalization transformer substation, and it is not only connected with crucial interface unit and Relay Protection Unit, also has other a large amount of equipment, as communication gate, and man-machine interface and gps clock etc.The smart machine using the communication protocol of standard that different manufacturer can be made to manufacture in network is easier to connecting system.Network sensor is joined together by interface unit, instead of is directly connected on relay as in traditional protection.A considerable amount of electric current and voltage transformer can be connected to interface unit.The voltage and current data that interface unit provides sequential coherent by the point-to-point mode of multichannel to protective relaying device.Meanwhile, fiber optic network also can receive the trip signal that sends from relaying protection and be sent to corresponding circuit breaker and perform.

Relay Protection Unit is arranged in each transformer station; collect the synchronous electric information in outlet in transformer station; main protection state and breaker actuation information; judge whether have fault to occur in station; calculate the direction of transformer station's each element place fault; and the fault direction at each element place is sent to protection intelligent centre, as the basis that wide area backup protection differentiates.

Protection intelligent centre collects the result of each transformer station relay unit in certain limit; fault element position can be determined through relevant wide area backup protection algorithm and make the Intellectualized Switchgear that tripping operation decision-making issues corresponding transformer station and perform, realize the backup protection of all elements in wide scope.Protection intelligent centre only need be equipped with communication module; abort situation calculates and tripping operation decision-making module; self do not need to carry out calculation process to the basic electric signal in the outlet of each transformer station; only collect the information crossed by each substation relay protection cell processing; thus reduce the requirement of the operational capability to protection intelligent centre, also mitigate communication pressure simultaneously.

Wide area backup protection based on protection intelligent centre is different from traditional backup protection configuration; no longer only for single system element; but utilize multiple spot information in electric power system; backup protection is provided to all elements in certain area; thus the complicated tuning process avoided in protective relaying device time definite value, and there is good adaptivity for electric power system different running method.

As shown in Figure 3; described Relay Protection Unit comprises the fault detection module, signal processing module and the abort situation discrimination module that are connected successively with merge cells in transformer station; also comprise the communication module communicated to connect with signal processing module and abort situation discrimination module; the tripping operation decision-making module be connected with abort situation discrimination module, described tripping operation decision-making module is connected with the circuit breaker in transformer station.

Below each module of Relay Protection Unit is described in detail:

By the fault initiating in fault detection module and phase selection element, fault detection module: under the whole network unified clock GPS, by the electric current and voltage information of element in this transformer station of merge cells Real-time Collection, has judged whether that fault occurs.

Signal processing module: after fault initiating element movement, calculates the fault direction information of each element in departures by the electric current and voltage information gathered and collects this Substation Station inner breaker action message and main protection operate condition.

Communication module: protection intelligent centre collects the fault direction information of bus-circuit association status matrix that substation relay protection unit in this wide area backup protection scope sends by wide area network, and the main protection actuating signal of fault element and circuit-breaker status.

Fault direction discrimination module: utilize the voltage of this transformer station element, current information to calculate fault and occur in the positive direction of this element still (voltage current phase difference or distance algorithm) in the other direction, utilize existing algorithm determination abort situation, improve the reliability that fault direction differentiates.

Tripping operation Executive Module: after fault direction discrimination module is judged to positive direction fault and receives the tripping operation information of protection intelligent centre, performs in conjunction with circuit-breaker status and main protection actuating signal the strategy that trips accordingly.

The present invention protects intelligent centre only to collect the fault message processed through each transformer station, is generally logical signal, as differentiation result or the failure detection result of direction component, and the voltage and current value not in the outlet of each transformer station.Decrease the information interchange amount between protection intelligent centre and each transformer station on the one hand, communication pressure of having releived, also reduce protection intelligent centre on the other hand to the disposal ability of bulk information, avoid " dimension calamity " occurs.

As shown in Figures 2 and 3, present system carries out the method for wide area backup protection, the electric parameters of current transformer and voltage transformer transmission is carried out merging with synchronous process and by sampled value network delivery to fault detection module by described merge cells, according to the electric parameters after process, fault detection module has judged whether that fault occurs, if there is fault to occur, then fault message is passed to signal processing module, fault direction is calculated by signal processing module, fault direction is passed to abort situation discrimination module, the decision-making of abort situation discrimination module is out of order position of components, then fault element position is passed to tripping operation decision-making module, the circuit breaker that tripping operation decision-making module tripping transformer station internal fault element is corresponding, the abort situation of the fault direction information that signal processing module calculates by described communication module and decision-making place of abort situation discrimination module passes to protection intelligent centre by wide area network, to be out of order position by fault location algorithm decision-making by protection intelligent centre, as the redundancy protecting of Relay Protection Unit in transformer station.

As shown in Figure 4, fault location algorithm comprises the steps:

Step 1: protection intelligent centre collects the state of wide area protection scope inner breaker by wide area network, determine the network topology structure of electric power system to be protected, thus form bus-circuit incidence matrices, the row corresponding substation bus bar respectively of this incidence matrices, row are corresponding substation bus bar interconnection respectively, matrix element is corresponding circuit breaker numbering, if substation bus bar interconnection is not directly connected with substation bus bar, then inserts element 0;

Step 2: in protection intelligent centre statistics bus-circuit incidence matrices, each row nonzero element number sum is designated as N _i, wherein i is line number, and by N _ibe stored in protection intelligent centre; After fault occurs; in each transformer station, Relay Protection Unit uploads fault direction information to protection intelligent centre; according to fault direction logical message, bus-circuit association status matrix is obtained to the bus-each row of circuit incidence matrices each row enlogy value, then draw the fault eigenvalue A of each substation bus bar interconnection within the scope of wide area protection by row summation respectively _i, summation draws the fault eigenvalue B of each substation bus bar within the scope of wide area protection by row _i, by A _iand B _irespectively with 2 and-N _icompare; determine fault occurrence positions; if the fault occurrence positions judged is substation bus bar fault of interconnected transmission line; in bus-circuit incidence matrices, then search for the circuit breaker numbering of the row correspondence at fault substation bus bar interconnection place; and this circuit breaker of time delay tripping; if the fault occurrence positions judged is substation bus fault; in bus-circuit incidence matrices, then search for the circuit breaker numbering that the row at fault substation bus bar place is corresponding; and this circuit breaker of time delay tripping, realize the near fast backup protection without adjusting.

Embodiment:

(1). the definition of the direction component D output at each breaker protection place is arranged on about correspondence.The positive direction of definition direction component is for flowing out bus.Current direction component is many to be made up of voltage current phase difference or impedance relay.The output valve of each direction component D has three kinds of possibilities:

(2). structure bus-circuit incidence matrices J.Wherein, matrix J be classified as substation bus bar interconnection sequence number, the bus sequence number of behavior transformer station, matrix element be between circuit and associated busbar circuit breaker numbering, if circuit and bus are not directly connected, then in matrix, corresponding element is 0.

(3). bus-circuit association status matrix J '.The value of bus-circuit incidence matrices element is each circuit breaker is protected corresponding direction component output valve.

Incidence matrices J describes the topological connection relation of circuit in protection range, circuit breaker and bus from the angle of mathematics, and should change with the change of system operation mode, structure.After system jam, fault direction logical message is sent to protection intelligent centre by each substation relay protection unit, to matrix J assignment formed association status matrix J '.Assuming that the electric power system of Fig. 5, its wide area backup protection system interactor is matrix J, its row corresponding substation bus bar interconnection L1 respectively, L2, L3, L4, L5, L6; Row is corresponding substation bus bar B1 respectively, B2, B3, B4, B5.According to the definition of matrix J, can matrix J be obtained by the electric power system topological structure of Fig. 5 as follows:

$J=\begin{array}{c}\begin{array}{cccccc}L1& L2& L3& L4& L5& L6\end{array}\\ \left[\begin{array}{cccccc}\mathrm{CB}1& \mathrm{CB}3& 0& 0& 0& 0\\ \mathrm{CB}2& 0& \mathrm{CB}4& \mathrm{CB}7& \mathrm{CB}9& 0\\ 0& 0& 0& \mathrm{CB}8& \mathrm{CB}10& \mathrm{CB}11\\ 0& 0& 0& 0& 0& \mathrm{CB}12\\ 0& \mathrm{CB}5& \mathrm{CB}6& 0& 0& 0\end{array}\right]\begin{array}{c}B1\\ B2\\ B3\\ B4\\ B5\end{array}\end{array}$

Assuming that the short circuit of k1 point, in system, fault direction as shown by the arrows in Figure 5, and the output logic value of direction component is substituted into matrix J, and the association status matrix obtaining its correspondence is J ' ₁, the short circuit of k2 point, in system, fault direction as shown by the arrows in Figure 6, and the association status matrix of its correspondence is J' ₂:

$\begin{array}{cc}{J}_1^{\′}=\left[\begin{array}{cccccc}1& -1& 0& 0& 0& 0\\ -1& 0& -1& 1& -1& 0\\ 0& 0& 0& 1& 1& -1\\ 0& 0& 0& 0& 0& 1\\ 0& 1& 1& 0& 0& 0\end{array}\right]& \end{array}{J}_2^{\′}=\left[\begin{array}{cccccc}1& -1& 0& 0& 0& 0\\ -1& 0& -1& 1& 1& 0\\ 0& 0& 0& -1& -1& -1\\ 0& 0& 0& 0& 0& 1\\ 0& 1& 1& 0& 0& 0\end{array}\right]$

(4). by association status matrix J ' determine abort situation

To matrix J ' each row sue for peace to obtain fault eigenvalue A corresponding to each interconnector _iif, A _iequal 2, then corresponding line is faulty line; To matrix J ' each row sues for peace to obtain corresponding substation bus fault characteristic value B _iif, B _iequal this transformer station all outgoing line side circuit breaker sums N _ithe opposite number of (namely often capable non-vanishing in matrix J element number), then there is fault bus in this transformer station inside.

Respectively k1 is asked to Fig. 5 and Fig. 6, each circuit, busbar fault characteristic value A under k2 point failure _i, B _i.

(a) .k1 point failure

To matrix J ' ₁each row respectively arranges and carries out summation operation and obtain:

J' ₁each row sum A _ibe respectively: 0,0,0,2,0,0; (i=1,2,3,4,5,6)

Wherein only has A ₄=2, then L4 is faulty line, consistent with k1 point failure in Fig. 5.

J' ₁each row sum B _ibe respectively: 0 ,-2,1,1,2; (i=1,2,3,4,5)

Known by Fig. 5, each transformer station all outgoing line side circuit breaker sums N _ibe respectively: 2,4,3,1,2; The first prime number non-vanishing with row each in matrix J is consistent, so there is not B _i=-N _i, namely within the scope of wide area protection without substation bus fault.

To sum up, can conclude within the scope of this wide area protection only there is a faulty line L4.

(b) .k2 point failure

To matrix J ' ₂each row respectively arranges and carries out summation operation and obtain:

J' ₂each row sum A _ibe respectively: 0,0,0,0,0,0; There is not A _i=2, therefore there is not substation bus bar fault of interconnected transmission line within the scope of wide area protection.

J' ₂each row sum B _ibe respectively: 0,0 ,-3,1,2; N _ibe still 2,4,3,1,2.B can be obtained ₃=-N ₃, namely there is fault bus in transformer station B3, consistent with k2 point failure in Fig. 6.

To sum up, can conclude within the scope of this wide area protection only there is a fault bus in transformer station B3.

In addition, to matrix J ' each row respectively arrange summation after, if both there is no A _i=2 do not have B yet _i=-N _i, then fault is not had within the scope of wide area protection; Very little for the probability that bus and line fault occur in electric power system simultaneously, so the present invention does not do to consider.

(5). determine nearly standby tripping operation sequence by abort situation

After determining that L4 is faulty line, in matrix J, search for the circuit breaker numbering that in L4 column, nonzero element is corresponding, be CB7, CB8.After certain time-delay (guarantee escape main protection operate time); if main protection tripping or fault current still exist; then send trip signal by protection intelligent centre to transformer station 2, transformer station 3, respectively tripping CB7, CB8 is as the nearly backup protection of interconnection L4.

After determining to there is fault bus in B3, search in matrix J B3 be expert in nonzero element corresponding circuit breaker numbering, be CB8, CB10, CB11.Through one section of time delay, by protection intelligent centre to transformer station's 3 trip signals, tripping CB8, CB10, CB11 are as the nearly backup protection of transformer station 3 busbar fault.

If Relay Protection Unit obtains the information of adjacent substations by protection intelligent centre, the Relay Protection Unit so in station also can determine abort situation with the fault location algorithm same with protection intelligent centre.

Known in sum, the wide area backup protection based on protection intelligent centre is adjusted without the need to complexity, can realize the nearly backup protection of element in electric power system fast.

Claims (5)

1. based on the wide area backup protection system of protection intelligent centre, it is characterized in that: comprise the GOOSE net gathering multiple transformer substation switch amount, gather the sampled value network of transformer station's electric parameters, the Relay Protection Unit be connected with GOOSE net and sampled value network, the protection intelligent centre be connected by wide area network with Relay Protection Unit, also comprises the merge cells be connected with voltage transformer with the current transformer of transformer station; The electric parameters of current transformer and voltage measuring transformer is carried out merging and synchronous process by described merge cells; and the digital electric amount after process is sent to Relay Protection Unit by sampled value network; the switching value of transformer station sends to Relay Protection Unit by GOOSE net; Relay Protection Unit calculates fault direction by gained electrical quantity; then the switching value received and the fault direction that calculates are passed to protection intelligent centre by wide area network, to be out of order position issue trip signal by the decision-making of protection intelligent centre.

2. the wide area backup protection system based on protection intelligent centre according to claim 1; it is characterized in that: described Relay Protection Unit comprises the fault detection module, signal processing module and the abort situation discrimination module that are connected successively with merge cells in transformer station; also comprise the communication module communicated to connect with signal processing module and abort situation discrimination module; the tripping operation decision-making module be connected with abort situation discrimination module, described tripping operation decision-making module is connected with the circuit breaker in transformer station.

3. the wide area backup protection system based on protection intelligent centre according to claim 1; it is characterized in that: described protection intelligent centre only collects the fault message processed through each transformer station; voltage and current value not in the outlet of each transformer station, and without the need to information interaction between transformer station.

4. protection system described in claim 2 carries out the method for wide area backup protection, it is characterized in that: the electric parameters of current transformer and voltage transformer transmission is carried out merging with synchronous process and by sampled value network delivery to fault detection module by described merge cells, according to the electric parameters after process, fault detection module has judged whether that fault occurs, if there is fault to occur, then fault message is passed to signal processing module, fault direction is calculated by signal processing module, fault direction is passed to abort situation discrimination module, the decision-making of abort situation discrimination module is out of order position of components, then fault element position is passed to tripping operation decision-making module, the circuit breaker that tripping operation decision-making module tripping transformer station internal fault element is corresponding, the abort situation of the fault direction information that signal processing module calculates by described communication module and decision-making place of abort situation discrimination module passes to protection intelligent centre by wide area network, to be out of order position by fault location algorithm decision-making by protection intelligent centre, as the redundancy protecting of Relay Protection Unit in transformer station.

5. method of carrying out wide area backup protection according to claim 4, is characterized in that: described fault location algorithm comprises the steps:

Step 1: protection intelligent centre collects the state of wide area protection scope inner breaker by wide area network, determine the network topology structure of electric power system to be protected, thus form bus-circuit incidence matrices, the row corresponding substation bus bar respectively of this incidence matrices, row are corresponding substation bus bar interconnection respectively, matrix element is corresponding circuit breaker numbering, if substation bus bar interconnection is not directly connected with substation bus bar, then inserts element 0;

Step 2: in protection intelligent centre statistics bus-circuit incidence matrices, each row nonzero element number sum is designated as N _i, wherein i is line number, and by N _ibe stored in protection intelligent centre; After fault occurs; in each transformer station, Relay Protection Unit uploads fault direction information to protection intelligent centre; according to fault direction logical message, bus-circuit association status matrix is obtained to the bus-each row of circuit incidence matrices each row enlogy value, then draw the fault eigenvalue A of each substation bus bar interconnection within the scope of wide area protection by row summation respectively _i, summation draws the fault eigenvalue B of each substation bus bar within the scope of wide area protection by row _i, by A _iand B _irespectively with 2 and-N _icompare; determine fault occurrence positions; if the fault occurrence positions judged is substation bus bar fault of interconnected transmission line; in bus-circuit incidence matrices, then search for the circuit breaker numbering of the row correspondence at fault substation bus bar interconnection place; and this circuit breaker of time delay tripping; if the fault occurrence positions judged is substation bus fault; in bus-circuit incidence matrices, then search for the circuit breaker numbering that the row at fault substation bus bar place is corresponding; and this circuit breaker of time delay tripping, realize the near fast backup protection without adjusting.