CN101572404A - Wide-area traveling-wave protection method - Google Patents

Abstract

The invention belongs to the field of power systems, and relates to a wide-area traveling-wave protection method. The method comprises the following steps that: two ends of all lines in a wide-area power network are provided with traveling-wave protection relays; a protection device sets a connection incidence matrix according to the connection relation between the traveling-wave protection relays and the lines and determines fault threshold values of all the lines; the traveling-wave protection relays record the polarities of initial traveling waves of voltage and current after the lines break down, compares the polarities of two initial traveling waves, and outputs comparison result to the protection device; and the protection device assigns value to the connection incidence matrix so as to form a fault incidence matrix according to the comparison result, determines the fault comprehensive values of the lines according to the fault incidence matrix, and compares all the fault comprehensive values with the fault threshold values of the corresponding lines respectively so as to judge faulty lines. As the method utilizes the polarities of all the initial traveling waves of voltage and current in the power network to protect the lines, the reliability and accuracy of traveling-wave protection actions can be effectively improved.

Description

Wide-area traveling-wave protection method

Technical field

The invention belongs to field of relay protection in power, relate to a kind of wide-area traveling-wave protection method.

Background technology

Proposed a series of traveling-wave protection method in succession after the seventies in 20th century, its principle mainly is to utilize information such as the polarity of initial row ripple, amplitude to constitute the protection criterion, can be divided into capable ripple direction protection, the row pitch of waves haply from protection and traveling-wave differential protection.These guard methods respectively have its pluses and minuses; its limitation is all arranged in actual applications; and these methods all are based on capable wave characteristic on the circuit and carry out route protection; the sensitivity of traveling-wave protection and reliability be subject to the catadioptric row ripple of other bus in the electrical network and the influence of high-frequency interferencing signal, so can't satisfy the service requirement of electric power system fully always.Along with the continuous development and the application of wide area network, in order to improve the performance of relaying protection system, people have proposed the notion of wide area relay protection and have carried out Primary Study in recent years.The proposition of wide area relay protection is to give full play to its ability according to the accurate failure judgement element of multiple spot fault message, traditional main protection replenished, thus more accurate, excise the system failure more quickly, improve the reliability of relaying protection system.Global position system GPS and express network development of Communication Technique and the ripe work clock that provides solid guarantee: GPS can make each transformer station for the wide-area traveling-wave protection system keep strict synchronism, and express network communication can make the rapid exchange message of energy between each transformer station.Nowadays most of transformer station has laid optic fibre of looped network; though can not guarantee the direct communication between any two websites; but they all can directly be connected with the power-management and communication centre, and traffic rate has reached more than the 2Mbit/s, for the information sharing between the traveling-wave protection device provides condition.

Summary of the invention

For overcoming the deficiency of prior art, the existing existing sensitivity of transmission line malfunction traveling-wave protection method of solution is hanged down the technical problem with poor reliability.The present invention is by means of the express network communication system; compare by voltage, electric current initial row ripple polar relationship the record of the traveling-wave protection relay on all circuits in the interconnected The Wide Area Power; fully utilize all polarity comparative results and carry out route protection; efficiently solve the not good enough problem of traveling-wave protection sensitivity and reliability, help further to improve the practicality of traveling-wave protection.

The technical scheme that the present invention solves the problems of the technologies described above may further comprise the steps:

1) the traveling-wave protection relay is installed at all circuit two ends in The Wide Area Power;

2) protective device is formulated with the annexation of circuit according to the traveling-wave protection relay and is connected incidence matrices, and determines the fault threshold values of all circuits;

3) polarity of traveling-wave protection relay recording voltage, electric current initial row ripple after the line fault compares the polarity of two kinds of initial row ripples, and comparative result is exported to protective device;

4) protective device forms the fault incidence matrices according to comparative result to connecting the incidence matrices assignment, according to the fault comprehensive value of related each circuit of matrix computations of fault, and all fault comprehensive values are compared the failure judgement circuit with the fault threshold values of respective lines respectively;

5) faulty line is judged end, protection outlet tripping operation.

Above-mentioned steps 2) the traveling-wave protection relay and the annexation of this circuit that are installed on certain circuit are directly related (with "+" expression), with the annexation of adjacent lines be that indirect correlation (is used

Expression), the annexation with non-conterminous circuit is uncorrelated (with " * " expression).

Above-mentioned steps 2) formulating the method that is connected incidence matrices according to circuit with the annexation of traveling-wave protection relay in is: if the circuit number in the The Wide Area Power is m; the quantity of traveling-wave protection relay is n; then connecting incidence matrices is that m * n ties up matrix; each row is represented a circuit in the matrix; each row is then represented a traveling-wave protection relay; concrete element in the matrix has been described the annexation of circuit and traveling-wave protection relay, and the form that connects incidence matrices is:

Above-mentioned steps 2) in second step fault threshold values of each circuit be: the fault threshold values of common two-termial line is 2; The fault threshold values of T link is 3.

Above-mentioned steps 3) the traveling-wave protection relay compares the voltage that is write down, the initial polarity of traveling wave of electric current in; when initial row ripple polarity is identical; the definition comparative result is-1; when initial row ripple polarity is opposite; the definition comparative result is 1; when not recording initial polarity of traveling wave or only recording a kind of initial row ripple polarity chron, the definition comparative result is 0.

Above-mentioned steps 4) protective device to the method that connects incidence matrices assignment formation fault incidence matrices is in: if certain traveling-wave protection relay is directly related with circuit, then the output valve of this traveling-wave protection relay is composed to the corresponding element that connects incidence matrices; If traveling-wave protection relay and circuit are indirect correlations or uncorrelated, the corresponding element assignment that then directly will connect incidence matrices is 0.

Above-mentioned steps 4) the fault comprehensive value of each circuit is calculated as follows in:

$D\left(i\right)=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{L}_{\mathrm{ij}}$

In the formula: D (i) be the pairing traveling-wave protection relay of i bar circuit output valve and; L _IjBe the capable j column element of fault incidence matrices i value.

Above-mentioned steps 4) carry out the failure judgement circuit by following formula in:

D(i)≥D _set(i)

D in the formula _SetBe fault threshold values.

Technique effect of the present invention is: the present invention installs the traveling-wave protection relay in every circuit two ends in whole The Wide Area Power; utilize the traveling-wave protection relay to detect the polarity of voltage, electric current initial row ripple; and polar relationship compared; by protective device the polarity comparative result of all traveling-wave protection relays is unified to handle then; and then the failure judgement circuit, and faulty line sent the protection trip command.The inventive method utilizes interior all voltages of electrical network, the initial polarity of traveling wave of electric current to carry out route protection, can effectively improve the reliability and the accuracy of traveling-wave protection action.

Below in conjunction with accompanying drawing the present invention is made further instructions.

Description of drawings

Fig. 1 is a The Wide Area Power simulation model of the present invention.

Embodiment

Referring to Fig. 1, Fig. 1 has 4 500kV transmission lines for implementing The Wide Area Power simulation model of the present invention in the simulation model, be respectively L ₁, L ₂, L ₃, L ₄, circuit L wherein ₄Longer; Have 4 buses, be respectively M, N, S, P.At circuit L ₁Traveling-wave protection relay 1 and traveling-wave protection relay 2 are installed in two ends, at circuit L ₂Traveling-wave protection relay 3 and traveling-wave protection relay 4 are installed in two ends, at circuit L ₃Traveling-wave protection relay 5 and traveling-wave protection relay 6 are installed in two ends, at circuit L ₄Traveling-wave protection relay 7 and traveling-wave protection relay 8 are installed in two ends.The connection incidence matrices of simulation model correspondence shown in Figure 1 is:

As circuit L ₂At k ₁After point breaks down, can be created in the travelling wave signal of propagating in the whole The Wide Area Power, all traveling-wave protection relays all can detect the polarity of travelling wave signal and recording voltage, electric current initial row ripple in this moment whole electrical network.The traveling-wave protection relay compares the polarity of voltage, electric current initial row ripple, and comparative result is sent to protective device, and protective device according to comparative result to connecting incidence matrices assignment formation fault incidence matrices is:

By the fault incidence matrices be by the fault comprehensive value that the inventive method can calculate each circuit correspondence:

$\left\{\begin{array}{c}D\left(L_1\right)=1+(-1)=0\\ D\left(L_2\right)=1+1=2\\ D\left(L_3\right)=1+(-1)=0\\ D\left(L_4\right)=(-1)+(-1)=-2\end{array}\right.$

Know that by the inventive method the fault threshold values of each circuit correspondence is respectively again:

$\left\{\begin{array}{c}{D}_{\mathrm{set}}\left(L_1\right)=2\\ D_{\mathrm{set}}\left(L_2\right)=2\\ D_{\mathrm{set}}\left(L_3\right)=2\\ D_{\mathrm{set}}\left(L_4\right)=2\end{array}\right.$

All fault comprehensive values are compared with the fault threshold values of respective lines respectively can judge circuit L ₂Be faulty line.

As can be seen from the above analysis, the inventive method has utilized the voltage of all traveling-wave protection relay records in the whole The Wide Area Power, the polarity of electric current initial row ripple to come the failure judgement circuit, and deterministic process is simple, the result is accurate, can carry out route protection reliably.

Claims (8)

1, a kind of wide-area traveling-wave protection method comprises the steps:

1) the traveling-wave protection relay is installed at all circuit two ends in The Wide Area Power;

2) protective device is formulated with the annexation of circuit according to the traveling-wave protection relay and is connected incidence matrices, and determines the fault threshold values of all circuits;

3) polarity of traveling-wave protection relay recording voltage, electric current initial row ripple after the line fault compares the polarity of two kinds of initial row ripples, and comparative result is exported to protective device;

4) protective device forms the fault incidence matrices according to comparative result to connecting the incidence matrices assignment, according to the fault comprehensive value of related each circuit of matrix computations of fault, and all fault comprehensive values are compared the failure judgement circuit with the fault threshold values of respective lines respectively;

5) faulty line is judged end, protection outlet tripping operation.

2, wide-area traveling-wave protection method according to claim 1; it is characterized in that: the traveling-wave protection relay and the annexation of this circuit that are installed in described step 2) on certain circuit are directly related (with "+" expression), with the annexation of adjacent lines be indirect correlation (with "

" expression), with the annexation of non-conterminous circuit be uncorrelated (with " * " expression).

3, wide-area traveling-wave protection method according to claim 1; it is characterized in that: formulating the method that is connected incidence matrices according to circuit with the annexation of traveling-wave protection relay described step 2) is: if the circuit number in the The Wide Area Power is m; the quantity of traveling-wave protection relay is n; then connecting incidence matrices is that m * n ties up matrix; each row is represented a circuit in the matrix; each row is then represented a traveling-wave protection relay; concrete element in the matrix has been described the annexation of circuit and traveling-wave protection relay, and the form that connects incidence matrices is:

4, wide-area traveling-wave protection method according to claim 1 is characterized in that: the fault threshold values of each circuit is described step 2): the fault threshold values of common two-termial line is 2; The fault threshold values of T link is 3.

5, wide-area traveling-wave protection method according to claim 1; it is characterized in that: the traveling-wave protection relay compares the voltage that is write down, the initial polarity of traveling wave of electric current in the described step 3); when initial row ripple polarity is identical; the definition comparative result is-1; when initial row ripple polarity is opposite; the definition comparative result is 1, and when not recording initial polarity of traveling wave or only recording a kind of initial row ripple polarity chron, the definition comparative result is 0.

6, wide-area traveling-wave protection method according to claim 1, it is characterized in that: protective device to the method that connects incidence matrices assignment formation fault incidence matrices is in the described step 4): if certain traveling-wave protection relay is directly related with circuit, then the output valve of this traveling-wave protection relay is composed to the corresponding element that connects incidence matrices; If traveling-wave protection relay and circuit are indirect correlations or uncorrelated, the corresponding element assignment that then directly will connect incidence matrices is 0.

7, wide-area traveling-wave protection method according to claim 1 is characterized in that: the fault comprehensive value of each circuit is calculated as follows in the described step 4):

$D\left(i\right)=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{L}_{\mathrm{ij}}$

In the formula: D (i) be the pairing traveling-wave protection relay of i bar circuit output valve and; L _IjBe the capable j column element of fault incidence matrices i value.

8, wide-area traveling-wave protection method according to claim 1 is characterized in that: carry out the failure judgement circuit by following formula in the described step 4):

D(i)≥D _set(i)

D in the formula _SetBe fault threshold values.