CN104330708A - Fault location method for wide area traveling wave signal below power grid - Google Patents

Abstract

The invention discloses a fault location method for wide area traveling wave signal below power grid, with a little of fault traveling wave monitoring points for the power grid, the fault signal is processed on the phase-mode transformation and the small wave mode maximum value process to obtain the initial wave header information; the extension double-end travelling wave fault location is realized in the complex power grid, the fault location method of general power grid is offered on this basis for fast finding the exact double-end ranging combination from the measured data, and raising the ranging precision by amending the result. The monitoring data is processed and checked for realizing extension double-end travelling wave fault location for any fault point of the system, and the method has good fault-tolerant capability.

Description

The Fault Locating Method of wide area travelling wave signal under general electrical network

Technical field

The present invention relates to the Fault Locating Method research being adapted to wide area travelling wave signal under general electrical network.

Background technology

It is growing that spatial dimension along with modern power systems constantly expands with technology when modern computer treatment technology, Digital Signal Processing, GPS synchronous school, and the Wide-area Measurement Information collection after complex electric network fault more and more easily realizes.Relay protection under wide area system and status monitoring research are also increased gradually; For reducing failure accident loss, the economic benefits reached and social benefit, will monitor the safety case of electrical network, and carry out quick position to fault, especially for wide area system, occurred the achievement in research of some maturations both at home and abroad.The variable effect being subject to system operational parameters due to traveling wave method is less, and considers that the identification of single end distance measurement method to reflection wave is more difficult, and the scope of application of some Improving ways is also less ^{[1] [2]}, therefore utilize the time-frequency local characteristics of small echo, the initial wave head due in of transient state travelling wave detected, and then use double-end distance measurement method to find range.The device that this direct use row ripple Monitoring Data carries out finding range is called TWR (Traveling Waves Recorder).

To in the Fault Location With Traveling Wave research under wide area system, its algorithm is mainly for radial distribution networks, if containing special constructions such as looped networks in system, so algorithm effect just may not reach desirable; Adopt neighbor point optimisation strategy to ask for shortest path, then obtain abort situation by linear regression analysis; Document ^[5]when the Conceptual Extension by both-end distance measuring, calculate the time arriving all monitoring points when each bar bus breaks down, when physical fault occurs based on the minimum time arriving pick-up unit, finally norm calculation is carried out to detected value and theoretical value, select the bus that two minimum norms are corresponding, and then determine faulty line, but, this method is limited to the design feature of circuit, the circuit of IEEE-14 system 82.2% can only be met, and automatically can not isolating faulty line rapidly, needing people for analyzing; Document ^[3,4]utilize the wide area of complex electric network capable ripple information realization localization of fault, consider the allocation problem of TWR in electrical network, but do not consider the fault-tolerance of its algorithm.

List of references

[1] Zhang Linli, Xu Bingyin, Xue Yongduan etc. based on the low current grounding transient state localization method [J] of line voltage and zero mould electric current. Proceedings of the CSEE, 2012,32 (13): 110-115.

[2] Tang Jinrui, Yin Xianggen, Zhang Zhe etc. zero mould detects the iterative extraction of wave velocity and the application [J] in one-phase earthing failure in electric distribution network location thereof. electrotechnics journal, 2013,28 (4): 202-211.

[3]MertKorkali,Hanoch Lev-Ari,Ali Abur.Traveling-Wave-Based Fault-Location Technique for Transmission Grids Via Wide-Area Synchronized Voltage Measurements[J].IEEE Trans.Power Del.,May 2012,27(2):1003-1011.

[4]Korkali M,Abur A.Optimal deployment of wide-area synchronized measurements for fault-location observability[J].Power Systems,IEEE Transactions on,2013,28(1):482-489.

[5]M.Korkali,A.Abur.Fault location in meshed power networks using synchronized measurements.Proc.North American Power Symp.,Sep.2010:1-6.

Summary of the invention

Goal of the invention: in order to overcome the deficiencies in the prior art, the invention provides the Fault Locating Method of wide area travelling wave signal under a kind of general electrical network, can realize expansion both-end travelling wave ranging, have good fault-tolerant ability to Arbitrary Fault point in system.

Technical scheme: for achieving the above object, the technical solution used in the present invention is:

1, the Fault Locating Method of wide area travelling wave signal under general electrical network, comprises the steps:

1) select optimal T WR allocation plan in the electrical network determined at topological structure, obtain priori; Described priori comprises the bee-line in electrical network between all bus nodes, the bus position that the TWR configured is corresponding, the one or more adjacent bus at the bus place of installation TWR and described one or more adjacent bus arrive the bee-line of each TWR respectively, line line velocity of wave propagation c _a; By described priori stored in database SQL-0;

2) suppose to configure K TWR in electrical network, when breaking down in electrical network, K TWR detects fault traveling wave voltage simultaneously, obtains by modular transformation and wavelet transformation the time T that the initial wavefront of fault arrives K TWR _mn(n=1 ~ K), n is the n-th TWR; At T _mnminimum value T is found in (n=1 ~ K) _min, known T _minthe installation bus position I of corresponding TWR _i; By Query Database SQL-0, known bus I _ithe adjacent bus I of p bar _vj(j=1 ~ p); Known adjacent bus I _vj(j=1 ~ p) arrives the bee-line D of K TWR respectively _vj(j=1 ~ p);

3) bus I is made _ithe TWR at place forms both-end travelling wave ranging with other K-1 TWR respectively and combines, and selects I arbitrarily _ian adjacent bus I _vj(j=1 ~ p), arranges initial j=1; Adopt when wherein carrying out both-end travelling wave ranging and comprise the bee-line that this adjacent bus arrives K TWR respectively; Can obtain K group failure message according to both-end travelling wave ranging technique computes, described failure message is faulty line R _mt(t=1 ~ K) and faulty line R _mtthe fault distance S of (t=1 ~ K) upper distance line head end _mt(t=1 ~ K); T is t group failure message;

4) initially make t=1, select one group of faulted-phase judgment arbitrarily: namely according to the faulty line R in this group _mtthe fault distance S that (t=1 ~ K) is corresponding with it _mt(t=1 ~ K) determines a position of failure point in corresponding electrical network, using this position of failure point as new node f;

5) according to the fault distance S in this selected group failure message _mt(t=1 ~ K), the distance S of the known new node f to each TWR of Query Database SQL-0 _f, according to the distance S of new node f to each TWR _fthe transmission time T of new node f to each TWR can be obtained _f;

6) T is calculated _mn(n=1 ~ K) and transmission time T _fmanhatton distance: H _n=|| T _f-T _mn|| (n=1 ~ K);

7) determining step 4) ~ step 6) in K group failure message whether be all disposed, namely whether t=K sets up, if establishment, then enter step 8); If be false, t=t+1, returns step 4);

8) K group manhatton distance can be obtained according to above step, in K group manhatton distance, find manhatton distance minimum value: Δ T _j=minH (j=1 ~ p), and record the combination of fault distance corresponding to this minimum value, faulty line and both-end travelling wave ranging, the data recorded are stored in database SQL-1;

9) step 3 is repeated) ~ step 8), obtain the minimum manhatton distance minimum value corresponding to the adjacent bus of every bar; Namely whether j=p sets up, and enters step 10 if set up); If be false, j=j+1, returns step 3);

10) minimum manhatton distance set is formed by the manhatton distance minimum value that the adjacent bus of p bar is corresponding separately: Δ T=[Δ T ₁Δ T ₂... Δ T _p]; Find the minimum value in Δ T, the both-end travelling wave ranging combination that Query Database SQL-1 obtains fault distance corresponding to this minimum value, faulty line and uses, both-end travelling wave ranging the combined ansatz method is T _minand T _k, by formula (T _min-t ₀) c _a+ (T _k-t ₀) c _a=L _iKobtain time of failure t ₀, wherein L _iKrepresent that this both-end travelling wave ranging combines bee-line used;

11) according to S _i=c _a(T _mn– t ₀), obtain the distance S of actual fault point to each TWR _i, then move towards Query Database SQL-0 by respective lines, obtain the physical fault distance S of off-line road head end on physical fault circuit that each TWR records _fact={ S _facti, i=1 ~ K};

12) to result S _facttest: if physical fault distance S _fact={ S _facti, i=1 ~ K} is for bearing or being greater than respective lines length or physical fault distance S _fact={ S _facti, in i=1 ~ K}, data do not meet 3 σ criterions, all delete corresponding physical fault range data; Suppose that finally also having m group physical fault range data to form calculates data group finally being measured fault distance is:

$S=\frac{1}{m}\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{S}_{\mathrm{facti}}^{*}.$

Beneficial effect:

The present invention seeks under electrical network has configured a small amount of fault traveling wave monitoring point situation, by obtaining primary wave header to the phase-model transformation of signal after fault and Wavelet Modulus Maxima process.Consider under complex electric network situation, realize expansion both-end travelling wave ranging, provide general electric network fault localization method on this basis, realize fast searching from measurement data and go out travelling wave ranging combination accurately, improved the precision of range finding by the correction of result.And the process passed through Monitoring Data and inspection, ensure can realize expansion both-end travelling wave ranging to Arbitrary Fault point in system, there is good fault-tolerant ability.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of Fault Locating Method;

Fig. 2 is I _iadjacent bus schematic diagram;

Fig. 3 is IEEE-30 modular system.

Embodiment

Below in conjunction with accompanying drawing, the present invention is further described.

1, the Fault Locating Method of wide area travelling wave signal under general electrical network, comprises the steps:

1) select optimal T WR allocation plan in the electrical network determined at topological structure, obtain priori; Described priori comprises the bee-line in electrical network between all bus nodes, the bus position that the TWR configured is corresponding, the one or more adjacent bus at the bus place of installation TWR and described one or more adjacent bus arrive the bee-line of each TWR respectively, line line velocity of wave propagation c _a; By described priori stored in database SQL-0;

2) suppose to configure K TWR in electrical network, when breaking down in electrical network, K TWR detects fault traveling wave voltage simultaneously, obtains by modular transformation and wavelet transformation the time T that the initial wavefront of fault arrives K TWR _mn(n=1 ~ K), n is the n-th TWR; At T _mnminimum value T is found in (n=1 ~ K) _min, known T _minthe installation bus position I of corresponding TWR _i; By Query Database SQL-0, known bus I _ithe adjacent bus I of p bar _vj(j=1 ~ p); Known adjacent bus I _vj(j=1 ~ p) arrives the bee-line D of K TWR respectively _vj(j=1 ~ p);

3) bus I is made _ithe TWR at place forms both-end travelling wave ranging with other K-1 TWR respectively and combines, and selects I arbitrarily _ian adjacent bus I _vj(j=1 ~ p), arranges initial j=1; Adopt when wherein carrying out both-end travelling wave ranging and comprise the bee-line that this adjacent bus arrives K TWR respectively; Can obtain K group failure message according to both-end travelling wave ranging technique computes, described failure message is faulty line R _mt(t=1 ~ K) and faulty line R _mtthe fault distance S of (t=1 ~ K) upper distance line head end _mt(t=1 ~ K); T is t group failure message;

4) initially make t=1, select one group of faulted-phase judgment arbitrarily: namely according to the faulty line R in this group _mtthe fault distance S that (t=1 ~ K) is corresponding with it _mt(t=1 ~ K) determines a position of failure point in corresponding electrical network, using this position of failure point as new node f;

5) according to the fault distance S in this selected group failure message _mt(t=1 ~ K), the distance S of the known new node f to each TWR of Query Database SQL-0 _f, according to the distance S of new node f to each TWR _fthe transmission time T of new node f to each TWR can be obtained _f;

6) T is calculated _mn(n=1 ~ K) and transmission time T _fmanhatton distance: H _n=|| T _f-T _mn|| (n=1 ~ K);

7) determining step 4) ~ step 6) in K group failure message whether be all disposed, namely whether t=K sets up, if establishment, then enter step 8); If be false, t=t+1, returns step 4);

8) K group manhatton distance can be obtained according to above step, in K group manhatton distance, find manhatton distance minimum value: Δ T _j=minH (j=1 ~ p), and record the combination of fault distance corresponding to this minimum value, faulty line and both-end travelling wave ranging, the data recorded are stored in database SQL-1;

9) step 3 is repeated) ~ step 8), obtain the minimum manhatton distance minimum value corresponding to the adjacent bus of every bar; Namely whether j=p sets up, and enters step 10 if set up); If be false, j=j+1, returns step 3);

10) minimum manhatton distance set is formed by the manhatton distance minimum value that the adjacent bus of p bar is corresponding separately: Δ T=[Δ T ₁Δ T ₂... Δ T _p]; Find the minimum value in Δ T, the both-end travelling wave ranging combination that Query Database SQL-1 obtains fault distance corresponding to this minimum value, faulty line and uses, both-end travelling wave ranging the combined ansatz method is T _minand T _k, by formula (T _min-t ₀) c _a+ (T _k-t ₀) c _a=L _iKobtain time of failure t ₀, wherein L _iKrepresent that this both-end travelling wave ranging combines bee-line used;

11) according to S _i=c _a(T _mn– t ₀), obtain the distance S of actual fault point to each TWR _i, then move towards Query Database SQL-0 by respective lines, obtain the physical fault distance S of off-line road head end on physical fault circuit that each TWR records _fact={ S _facti, i=1 ~ K};

12) to result S _facttest: if physical fault distance S _fact={ S _facti, i=1 ~ K} is for bearing or being greater than respective lines length or physical fault distance S _fact={ S _facti, in i=1 ~ K}, data do not meet 3 σ criterions, all delete corresponding physical fault range data; Suppose that finally also having m group physical fault range data to form calculates data group finally being measured fault distance is:

$S=\frac{1}{m}\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{S}_{\mathrm{facti}}^{*}.$

The effect assessment of scheme:

Herein on the basis of specifying TWR allocation plan, a kind of wide area novel row ripple location algorithm is proposed.Allocation plan feasible system is maximum considerable, and namely during any line failure, at least there is a pair TWR can carry out both-end distance measuring to it.Now for a model:

In order to the fault-tolerant ability of verification algorithm, first in supposing the system, TWR all normally works, and carries out localization of fault, then artificially arrange fault TWR by ranging step, the correctness of algorithm when inspection TWR cannot normally work.

This example uses IEEE-30 modular system, as shown in Figure 3.TWR configures bus position: 2,3,5,8,11,13,14,16,18,21,26,29,30.

Arranging faulty line is circuit 4-6, and fault occurs in distance 4 bus 25km places, and fault type is set to phase fault.Time of failure is 20ms.Note: in example, line length unit uses km, does not use English unit; In addition, high frequency rolls off the production line mould velocity of propagation c _a=299.15km/s.

Error-free received data situation

The initial wavefront of fault arrives the time T of 13 TWR _mas shown in table 1 below:

The each TWR of table 1 detects initial row ripple time of arrival

Known from TWR Monitoring Data, T _min=t ₁₃.Combined by the range finding of other TWR and No. 13 TWR that often to be organized result as shown in table 2 below:

Table 2 fault localization PRELIMINARY RESULTS

In table, manhatton distance is minimum is the combination of No. 13 TWR and No. 30 TWR, and therefore, using No. 13 and No. 30 range measurement obtained as the basis calculated later, obtaining fault is apart from No. 4 bus 25.0729km circuit 4-6 on, calculating t fault-time ₀for 20.0004ms, the physical fault time is 20ms, and absolute error is 0.42 μ s.Afterwards, with t fault-time ₀as calculating data, obtain the fault distance that each TWR records as shown in table 3 below:

Table 3 corrects rear fault distance

Finally, calculating data mean value obtains fault is that absolute error is 16.90m apart from 4 bus 25.0169km places on circuit 4-6.Relative error is 0.07%.

Fault-tolerant ability is verified

For verifying the fault-tolerant ability of this algorithm, on upper routine basis, to 5, the TWR on 16, No. 26 buses arranges fault monitoring value: 22.9730ms, 22.5050ms, 25.5770ms.

Minimum time remains t ₁₃, the TWR that corresponding No. 13 buses are corresponding.By correction algorithm step, obtain step 9) data of database SQL-1 of trying to achieve, as shown in table 4 below:

Table 4 fault localization PRELIMINARY RESULTS

Visible according to data in table, 5,16, the TWR on No. 26 buses records fault distance and is ∞, when such following steps select minimum manhatton distance, will delete the Monitoring Data of these three TWR, and use remaining data to proceed analysis.Finally obtain the fault distance S that each TWR records _fact, as shown in table 5 below:

Table 5 corrects rear fault distance

Finally, obtaining fault is: apart from 4 bus 25.0006km on circuit 4-6, absolute error is 0.63m.Through simulating, verifying, compared to other location algorithms, the method positioning precision is high, can be suitable for the electrical network of any type, and has good fault-tolerant ability.

The above is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (1)

1. the Fault Locating Method of wide area travelling wave signal under general electrical network, is characterized in that: comprise the steps:

1) select optimal T WR allocation plan in the electrical network determined at topological structure, obtain priori; Described priori comprises the bee-line in electrical network between all bus nodes, the bus position that the TWR configured is corresponding, the one or more adjacent bus at the bus place of installation TWR and described one or more adjacent bus arrive the bee-line of each TWR respectively, line line velocity of wave propagation c _a; By described priori stored in database SQL-0;

2) suppose to configure K TWR in electrical network, when breaking down in electrical network, K TWR detects fault traveling wave voltage simultaneously, obtains by modular transformation and wavelet transformation the time T that the initial wavefront of fault arrives K TWR _mn(n=1 ~ K), n is the n-th TWR; At T _mnminimum value T is found in (n=1 ~ K) _min, known T _minthe installation bus position I of corresponding TWR _i; By Query Database SQL-0, known bus I _ithe adjacent bus I of p bar _vj(j=1 ~ p); Known adjacent bus I _vj(j=1 ~ p) arrives the bee-line D of K TWR respectively _vj(j=1 ~ p);

3) bus I is made _ithe TWR at place forms both-end travelling wave ranging with other K-1 TWR respectively and combines, and selects I arbitrarily _ian adjacent bus I _vj(j=1 ~ p), arranges initial j=1; Adopt when wherein carrying out both-end travelling wave ranging comprise this adjacent bus arrive respectively K TWR bee-line; Can obtain K group failure message according to both-end travelling wave ranging technique computes, described failure message is faulty line R _mt(t=1 ~ K) and faulty line R _mtthe fault distance S of (t=1 ~ K) upper distance line head end _mt(t=1 ~ K); T is t group failure message;

4) initially make t=1, select one group of faulted-phase judgment arbitrarily: namely according to the faulty line R in this group _mtthe fault distance S that (t=1 ~ K) is corresponding with it _mt(t=1 ~ K) determines a position of failure point in corresponding electrical network, using this position of failure point as new node f;

5) according to the fault distance S in this selected group failure message _mt(t=1 ~ K), the distance S of the known new node f to each TWR of Query Database SQL-0 _f, according to the distance S of new node f to each TWR _fthe transmission time T of new node f to each TWR can be obtained _f;

6) T is calculated _mn(n=1 ~ K) and transmission time T _fmanhatton distance: H _n=|| T _f-T _mn|| (n=1 ~ K);

7) determining step 4) ~ step 6) in K group failure message whether be all disposed, namely whether t=K sets up, if establishment, then enter step 8); If be false, t=t+1, returns step 4);

8) K group manhatton distance can be obtained according to above step, in K group manhatton distance, find manhatton distance minimum value: Δ T _j=minH (j=1 ~ p), and record the combination of fault distance corresponding to this minimum value, faulty line and both-end travelling wave ranging, the data recorded are stored in database SQL-1;

9) step 3 is repeated) ~ step 8), obtain the minimum manhatton distance minimum value corresponding to the adjacent bus of every bar; Namely whether j=p sets up, and enters step 10 if set up); If be false, j=j+1, returns step 3);

10) minimum manhatton distance set is formed by the manhatton distance minimum value that the adjacent bus of p bar is corresponding separately: Δ T=[Δ T ₁Δ T ₂... Δ T _p]; Find the minimum value in Δ T, the both-end travelling wave ranging combination that Query Database SQL-1 obtains fault distance corresponding to this minimum value, faulty line and uses, both-end travelling wave ranging the combined ansatz method is T _minand T _k, by formula (T _min-t ₀) c _a+ (T _k-t ₀) c _a=L _iKobtain time of failure t ₀, wherein L _iKrepresent that this both-end travelling wave ranging combines bee-line used;

11) according to S _i=c _a(T _mn– t ₀), obtain the distance S of actual fault point to each TWR _i, then move towards Query Database SQL-0 by respective lines, obtain the physical fault distance S of off-line road head end on physical fault circuit that each TWR records _fact={ S _facti, i=1 ~ K};

12) to result S _facttest: if physical fault distance S _fact={ S _facti, i=1 ~ K} is for bearing or being greater than respective lines length or physical fault distance S _fact={ S _facti, in i=1 ~ K}, data do not meet 3 σ criterions, all delete corresponding physical fault range data; Suppose that finally also having m group physical fault range data to form calculates data group finally being measured fault distance is:

$S=\frac{1}{m}\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{S}_{\mathrm{facti}}^{*}.$