CN108375713A - A kind of novel power grid functional failure travelling wave positioning method and system - Google Patents

Abstract

The invention discloses a novel traveling wave location method and system for grid faults. This method records the time when the transient traveling wave signal generated by the fault point arrives at each substation after a transmission line fault in the power grid, and establishes a time matrix; uses the Dijkstra algorithm to calculate the shortest path of fault traveling wave propagation, establishes the shortest path distance matrix, and corrects Finally, the calculation matrix is obtained; the calculation matrix and the time matrix are used to calculate the fault distance, and the fault distance matrix is established; the elements in the fault distance matrix are effectively identified, and all effective fault distances are integrated to obtain the precise location of the fault point on the transmission line. The system includes a traveling wave detection device, a first building block, a double-end positioning module, a second building block and an effective identification module. The method and system of the present invention have high fault location accuracy, and can still realize accurate fault location even in the case of missing or miscollected traveling wave data, the realization process is simple and easy, and has broad application prospects.

Description

A Novel Traveling Wave Location Method and System for Power Grid Faults

technical field

The invention relates to the technical field of power fault traveling wave location in an electrical system, in particular to a new type of power grid fault traveling wave location method and system.

Background technique

Traveling wave is a kind of transmission state of plane wave on the transmission line. Its amplitude changes exponentially along the propagation direction, and its phase changes linearly along the transmission line. From the inspection of adjacent time t1 and t1+△t, it can be found that the waveform increases with time while moving toward the end of the transmission line. The traveling wave fault location method of power transmission and distribution system is to determine the distance of the fault point according to the reflection characteristics of the wave impedance discontinuous node on the transmission line. Power grid fault traveling wave location and protection is the key technology to ensure the safe and reliable operation of the power system. Because the traveling wave method is simple in principle, it has high positioning accuracy and has unique advantages such as not being affected by transition resistance, system operation mode, system oscillation and long-term distributed capacitance. , has become a research hotspot at home and abroad. With the continuous expansion of the scale of my country's power system and the continuous improvement of the safety and reliability requirements of the power grid, it is of great scientific significance and application prospect to carry out research on fault location technology of power grid fault traveling wave and promote the practical application of traveling wave technology.

Through the continuous efforts of many experts and scholars at home and abroad, the traveling wave positioning technology is becoming more and more mature, but there are still many deficiencies in the traveling wave positioning technology of the AC power grid. At present, there are many traveling wave location technologies for power grid faults, which can be divided into single-end location method, multi-terminal location method and network location method according to the collected location. The single-end positioning method is based on the wave transmission theory. When the wave speed is known, the fault point is calculated by using the time difference between the initial traveling wave generated by the fault and the reflected wave of the fault point arriving at the monitoring point. The initial traveling wave generated by the fault is detected, and the distance to the fault is calculated by using the time difference between the traveling wave reaching both ends and the wave velocity. However, some schemes in the research results of traveling wave fault location that have been published so far can effectively realize fault location in a power grid with a simple network structure, but it is difficult to The effective simplification of the network structure makes the calculation of the ring network solution complex, the amount of data processing is large, the calculation accuracy is reduced, and the error of fault location is relatively large.

To sum up, the traveling wave fault location scheme in the prior art has the technical problem of being unable to accurately locate the fault point when faced with a complex power grid structure such as a multi-ring power grid.

Contents of the invention

The purpose of the present invention is to provide a novel power grid fault traveling wave location method and system to solve the technical problem that existing technology traveling wave fault location schemes cannot accurately locate the fault point in the face of complex power grid structures such as multi-ring power grids.

To achieve the above object, the present invention provides the following scheme:

A novel traveling wave location method for grid faults, comprising the steps of:

Record the time when the initial traveling wave generated by the fault point in the power grid of the target area reaches all substations, and establish a time matrix T;

Use Dijkstra algorithm (Dijkstra algorithm, also called Dijkstra algorithm) to calculate the shortest path of fault traveling wave propagation, establish the shortest path distance matrix L, and obtain the calculation matrix L' after correction;

Select the shortest path sequentially from the calculation matrix L', and select the corresponding time element from the time matrix T, and calculate the fault distance d _ij using the double-ended positioning algorithm in the traveling wave positioning method;

According to the action of the protection device circuit breaker, the faulty transmission line is judged, and one end node c of the faulty transmission line is selected as the reference node, and all fault distances d _ij are converted to the reference node to obtain the converted fault distance d′ _ij , using all Establish the fault distance matrix D by calculating the fault distance d′ _ij ;

Identify the validity of all converted fault distances d′ _ij in the fault distance matrix D, and set weights for all non-zero effective elements in the fault distance matrix D to obtain the weight matrix W. By integrating the fault distance matrix D and the weight matrix W, the calculation is accurate The fault distance d _c .

Preferably, said step of establishing a time matrix T includes establishing the following time matrix T:

T＝[t ₁ ...t _i ...t _n ]

In the formula: n is the number of substations, t ₁ , t ₂ ... t _i ... t _n represent the time when the initial traveling wave generated by the fault point reaches the substation 1, 2 ... i ... n respectively;

The step establishes the shortest path distance matrix L, which specifically includes the steps:

Assuming that there are n nodes in the power grid topology diagram, the length of the line is selected as the weight value, and the weighting matrix V is constructed:

in:

In the formula: l _ij represents the line length between connected node i and node j, (please clarify the definition of v _ij );

According to the length of the line in the weighting matrix V, the Dijkstra algorithm is used to calculate the shortest path between any two nodes, and the shortest path distance matrix L is obtained:

In the formula: L _ij represents the length sum of the shortest path between node i and node j.

Preferably, the calculation matrix L' is obtained after the steps are corrected, which specifically includes the steps of:

The shortest path distance moment L is a symmetric matrix, and each shortest path is an undirected path, L _ij =L _ji , in order to avoid repeated calculation, when i<j, let L _ij =0;

When the faulty line is not in the ring network, all the shortest path elements L _ij that do not pass through the faulty line are corrected to 0, and other elements do not need to be corrected;

When the faulty line is in the ring network, correct it according to the following steps:

①If the two nodes i and j of the shortest path element L _ij are not in the ring network where the faulty line is located, when the shortest path has no line in the ring network, the element is corrected to 0; when the shortest path has a line in the ring network , determine whether the shortest path contains faulty lines, and no correction is required if it is included, otherwise the shortest path is disconnected from the lines in the ring network, and go to step ④;

②If the two nodes i and j of the shortest path element L _ij are both in the ring network where the faulty line is located, when one of the nodes i and j is the end node of the faulty line, correct the element to 0; otherwise, judge whether the shortest path is Include the faulty line, no correction is required if it is included, and disconnect the shortest path from the line in the ring network if it is not included, go to step ④;

③ If one of the two nodes i and j of the shortest path element L _ij is in the ring network where the faulty line is located, when there is no line in the shortest path in the ring network, the element is corrected to 0; when the shortest path is consistent with the corresponding initial The traveling wave arrival time is paired for calculation, and when the fault distance is approximately 0 or approximately equal to the length of the shortest path L _ij , modify the L _ij element to 0; otherwise, the shortest path is disconnected from the line in the ring network, and then go to step ④;

④ Use the Dijkstra algorithm to recalculate the shortest path between two nodes i and j until the shortest path includes the shortest path of the faulty line. After the calculation, the shortest path including the faulty line is taken as the value of the element L _ij ;

After all the elements are corrected, the calculation matrix L' is obtained.

Preferably, the step calculates the fault distance d _ij using the double-terminal positioning algorithm in the traveling wave positioning method, specifically including steps:

Find d _ij :

In the formula: d _ij represents the distance between the fault point and node i on the shortest path between node i and node j, L _ij represents the sum of the lengths of the shortest path between node i and node j, and v represents the fault point generation The propagation speed of the initial traveling wave on the transmission line.

Preferably, the step converts all the fault distances d _ij to the reference node to obtain the converted fault distance d′ _ij , which specifically includes the steps of:

Find d′ _ij :

d′ _ij ＝|d _ij -d _ic |

In the formula: d _ic represents the shortest distance between node i and node c.

Preferably, the step identifies the validity of all converted fault distances d' _ij in the fault distance matrix D, sets weights for all non-zero effective elements in the fault distance matrix D, and obtains a weight matrix W, and integrates the fault distance matrix D and the weight The matrix W is calculated to obtain the accurate fault distance d _c , which specifically includes the steps:

Select a converted fault distance from the fault distance matrix D, defined as Compare it with all converted fault distances d′ _ij in the fault distance matrix D according to the following formula in turn:

In the formula: α is the error threshold;

When the number satisfying the above formula is greater than half of the number of converted fault distances in the fault distance matrix D, it is considered that the converted fault distance Valid; otherwise, it is considered invalid and replaced with 0;

The weight calculation method of the non-zero elements in the fault distance matrix D is:

Assuming that each effective element in the fault distance matrix D corresponds to the number of substations passing through the shortest path is m, then the weight of this element can be set to 1/(m-1), and the weight matrix W can be obtained;

The calculation method of fault distance d _c is:

In the formula: W _ij is the weight of effective element d _ij of fault distance matrix D.

The present invention also provides a novel grid fault traveling wave location system, including:

The traveling wave detection device is installed in all substations in the power grid of the target area, and is used to record the time when the initial traveling waves generated by the fault point reach each substation;

The first building block is used to establish the time matrix T, and use the Dijkstra algorithm to calculate the shortest path of fault traveling wave propagation, establish the shortest path distance matrix L, and obtain the calculation matrix L' after correction;

The dual-terminal positioning operation module is used to sequentially select the shortest path from the calculation matrix L', select the corresponding time element from the time matrix T, and calculate the fault distance d by using the dual-terminal positioning algorithm in the traveling wave positioning method _ij ;

The second building block is used to judge the faulty transmission line according to the action of the circuit breaker of the protection device, select one end node c of the faulty transmission line as a reference node, convert all fault distances d _ij to the reference node, and obtain the converted fault distance d' _ij , using all the converted fault distances d' _ij to establish a fault distance matrix D;

The effective identification module is used to identify the validity of all converted fault distances d′ _ij in the fault distance matrix D, set weights for all non-zero effective elements in the fault distance matrix D, and obtain the weight matrix W, and integrate the fault distance matrix D and the weight The matrix W is calculated to obtain the precise fault distance d _c .

Preferably, the first building block is used for:

Create the following time matrix T:

T＝[t ₁ ...t _i ...t _n ]

In the formula: n is the number of substations, t ₁ , t ₂ ... t _i ... t _n represent the time when the initial traveling wave generated by the fault point reaches the substation 1, 2 ... i ... n respectively;

Assuming that there are n nodes in the power grid topology diagram, the length of the line is selected as the weight value, and the weighting matrix V is constructed:

in:

In the formula: l _ij represents the line length between connected node i and node j, (please clarify the definition of v _ij );

According to the length of the line in the weighting matrix V, the Dijkstra algorithm is used to calculate the shortest path between any two nodes, and the shortest path distance matrix L is obtained:

In the formula: L _ij represents the sum of the lengths of the lines passed by the shortest path between node i and node j;

The shortest path distance moment L is a symmetric matrix, and each shortest path is an undirected path, L _ij =L _ji , in order to avoid repeated calculation, when i<j, let L _ij =0;

When the faulty line is not in the ring network, all the shortest path elements L _ij that do not pass through the faulty line are corrected to 0, and other elements do not need to be corrected;

When the faulty line is in the ring network, correct it according to the following steps:

①If the two nodes i and j of the shortest path element L _ij are not in the ring network where the faulty line is located, when the shortest path has no line in the ring network, the element is corrected to 0; when the shortest path has a line in the ring network , determine whether the shortest path contains faulty lines, and no correction is required if it is included, otherwise the shortest path is disconnected from the lines in the ring network, and go to step ④;

②If the two nodes i and j of the shortest path element L _ij are both in the ring network where the faulty line is located, when one of the nodes i and j is the end node of the faulty line, correct the element to 0; otherwise, judge whether the shortest path is Include the faulty line, no correction is required if it is included, and disconnect the shortest path from the line in the ring network if it is not included, go to step ④;

③ If one of the two nodes i and j of the shortest path element L _ij is in the ring network where the faulty line is located, when there is no line in the shortest path in the ring network, the element is corrected to 0; when the shortest path is consistent with the corresponding initial The traveling wave arrival time is paired for calculation, and when the fault distance is approximately 0 or approximately equal to the length of the shortest path L _ij , modify the L _ij element to 0; otherwise, the shortest path is disconnected from the line in the ring network, and then go to step ④;

④ Use the Dijkstra algorithm to recalculate the shortest path between two nodes i and j until the shortest path includes the shortest path of the faulty line. After the calculation, the shortest path including the faulty line is taken as the value of the element L _ij ;

After all the elements are corrected, the calculation matrix L' is obtained.

Preferably, the double-ended positioning operation module is used to obtain d _ij :

In the formula: d _ij represents the distance between the fault point and node i on the shortest path between node i and node j, L _ij represents the sum of the lengths of the shortest path between node i and node j, and v represents the fault point generation The propagation speed of the initial traveling wave on the transmission line;

The second building block is used to obtain d′ _ij :

d′ _ij ＝|d _ij -d _ic |

In the formula: d _ic represents the shortest distance between node i and node c.

Preferably, the effective identification module is used for:

Select a converted fault distance from the fault distance matrix D, defined as Compare it with all converted fault distances d′ _ij in the fault distance matrix D according to the following formula in turn:

In the formula: α is the error threshold value, and the value range of α is 450-550 meters, preferably 500 meters.

When the number satisfying the above formula is greater than half of the number of converted fault distances in the fault distance matrix D, it is considered that the converted fault distance Valid; otherwise, it is considered invalid and replaced with 0;

The weight calculation method of the non-zero elements in the fault distance matrix D is:

Assuming that each effective element in the fault distance matrix D corresponds to the number of substations passing through the shortest path is m, then the weight of this element can be set to 1/(m-1), and the weight matrix W can be obtained;

The calculation method of fault distance d _c is:

In the formula: W _ij is the weight of effective element d _ij of fault distance matrix D.

According to the specific embodiments provided by the invention, the invention discloses the following technical effects:

The present invention provides a novel traveling wave location method and system for power grid faults. When a transmission line in the power grid in the target area fails, the fault point generates a transient traveling wave signal, which propagates to both ends of the transmission line and records all substation faults. The arrival time of the initial traveling wave generated at the point, and establish a time matrix; use the Dijkstra algorithm to calculate the shortest path of fault traveling wave propagation, establish the shortest path distance matrix, and obtain the calculation matrix after correction; use the calculation matrix and time matrix to calculate the fault distance, and establish the fault distance matrix; the elements in the fault distance matrix are effectively identified, and all effective fault distances are integrated to obtain the precise position of the fault point on the transmission line. The method and system provided by the present invention, by using the calculation matrix L' and the time matrix T, The fault distance matrix D is directly established; there is no need to solve the network operation of the ring network, which avoids the situation that the complex ring network may not be able to solve the network, and can also realize the precise positioning of the fault point in the face of the complex grid structure, which solves the problem of the existing technology grid. The fault traveling wave positioning method needs to face the technical problems of complex ring network solution network calculation and fault positioning failure or large positioning error. Experimental simulations show that the traveling wave positioning method and system provided by the present invention can be used in cases where traveling wave data is missed or miscollected. It can still achieve accurate fault location even under the same circumstances, effectively improving the reliability and accuracy of power grid fault location.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Fig. 1 is the flow chart of a kind of novel grid fault traveling wave location method of the present invention;

Figure 2 is an example of a typical model of the grid structure of a 500KV transmission line.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In order to make the technical solution of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with specific embodiments.

Referring to Fig. 1, an embodiment of the present invention provides a novel traveling wave location method for grid faults, including steps:

Step S110, record the time when the initial traveling wave generated by the fault point in the power grid of the target area reaches all substations, and establish a time matrix T.

Step S111, using the Dijkstra algorithm to calculate the shortest path of fault traveling wave propagation, establishing the shortest path distance matrix L, and obtaining the calculation matrix L' after correction.

Step S112, select the shortest path in sequence from the calculation matrix L', select the corresponding time element from the time matrix T, and calculate the fault distance d _ij by using the double-terminal positioning algorithm in the traveling wave positioning method.

Step S113, according to the action of the protection device circuit breaker to determine the faulty transmission line, select one end node c of the faulty transmission line as a reference node, convert all fault distances d _ij to the reference node, and obtain the converted fault distance d' _ij , A fault distance matrix D is established by using all the converted fault distances d' _ij .

Step S114, identify the validity of all converted fault distances d′ _ij in the fault distance matrix D, set weights for all non-zero effective elements in the fault distance matrix D, and obtain a weight matrix W, and integrate the fault distance matrix D and the weight matrix W, Calculate the precise fault distance d _c .

A specific embodiment of the novel power grid fault traveling wave location method of the present invention is listed below. In this embodiment, the power grid structure shown in FIG. 2 is used as the target regional power grid for fault location. The Figure 2 shows a typical model example of a 500KV transmission line grid structure.

Firstly, a traveling wave location network is constructed according to the grid structure. Use EMTP simulation software to simulate and analyze the power grid structure model shown in Figure 2. 1-8 are eight substations. Use the substation traveling wave detection device to detect and record the arrival time of the initial traveling wave generated by the fault point. When constructing the EMTP simulation model, consider The influence of transition resistance, substation capacitive equipment, line parameters, bus connection mode, wave trap and other factors on fault traveling wave propagation, all lines are constructed using a distributed parameter model (J.Marti model) considering the influence of frequency variation.

With the system shown in Figure 2, the fault traveling wave location analysis is carried out from the two cases where the initial traveling wave arrival time data of all fault points recorded by the substation detection are valid and there is invalid time data:

When all time data are valid, fault traveling wave location analysis includes the following steps:

(1) Assuming that a single-phase ground fault occurs 30km away from the fourth substation on line 4-6, the initial traveling wave generated by the fault point propagates throughout the power grid, and the arrival time of the initial traveling wave signal detected by each substation is established as the time matrix T:

T＝[t ₁ ...t _i ...t ₈ ]

The values of the matrix elements t ₁ -t ₈ in the above formula correspond to the initial traveling wave arrival times of the fault points recorded in the 1st to 8th substations in Table 1, respectively. See Table 1, Table 1 is the arrival time table of the initial traveling wave.

Table 1

(2) Construct the weighting matrix V according to the length of the line:

(3) Use the Dijkstra algorithm to calculate the shortest path between any two nodes, and use L _ij to represent the length of the shortest path between node i and node j, and obtain the shortest path distance matrix L:

(4) Correct the elements of the shortest path matrix L to obtain the calculation matrix L':

(5) Select the shortest path sequentially from the calculation matrix L′, select the corresponding time from the time matrix T, and calculate the fault distance d _ij according to the double-ended positioning algorithm. The traveling wave transmission speed is 2.96× ¹⁰⁸ m/s, and the The substation is the reference node, and all the fault distances d _ij are converted to the reference node 4 to obtain the fault distance matrix D:

(6) Identify the validity of all the converted fault distances d' _ij in the fault distance matrix D, and the discrimination results show that all the converted fault distances d' _ij in the fault distance matrix D are valid.

(7) Set weights for all effective elements in the fault distance matrix D to obtain the weight matrix W:

(8) Combine the fault distance matrix D and the weight matrix W to calculate the precise fault distance d _c .

The simulation analysis results show that the fault distance of the grid fault location is 30.020km, the error of the fault distance is small, and it is smaller than the error of the fault distance calculated only by using the initial traveling wave arrival time at both ends of the fault line, indicating that the grid fault location can be To a certain extent, the accuracy of fault location is improved.

For fault traveling wave location analysis with invalid time in all recorded arrival time data, the following two cases are included:

a. The arrival time error of the initial traveling wave recorded by the substation at one end of the fault line is large.

Assuming that the initial traveling wave arrival time recorded by substation 4 has a large error, which is t ₄ =150μs, and other initial traveling wave arrival times remain unchanged, the analysis steps: (1)-(4) and all initial traveling wave arrival time data are valid The fault location analysis steps (1)-(4) are the same; (5) The fault distance matrix D is updated according to the assumed conditions:

(6) To identify the validity of all converted fault distances d′ _ij in the fault distance matrix D, the correction is:

(7) Set weights for all effective elements in the fault distance matrix D, and obtain the weight matrix W as:

(8) Combine the fault distance matrix D and the weight matrix W to calculate the precise fault distance d _c :

b. The substation at one end of the fault line did not detect the arrival time of the initial traveling wave at the fault point.

Assuming that no traveling wave signal is detected in substation 6, at this time t ₆ =0μs, the analysis steps: (1)-(4) are the same as the fault location analysis steps (1)-(4) when all initial traveling wave arrival time data are valid ; (5) The fault distance matrix D is:

(6) Identify the validity of all the converted fault distances d' _ij in the fault distance matrix D, and the discrimination results show that all the converted fault distances d' _ij in the fault distance matrix D are valid.

(7) Set weights for all effective elements in the fault distance matrix D, and obtain the weight matrix W as:

(8) Combine the fault distance matrix D and the weight matrix W to calculate the precise fault distance d _c :

The simulation analysis results show that the present invention can still perform reliable fault location calculations when the data at the faulty line end is wrong or the data of the initial traveling wave arrival time at the fault point detected and recorded by other substations is wrong.

The embodiment of the present invention also provides a novel traveling wave location system for grid faults, which includes a traveling wave detection device, a first building block, a double-terminal positioning module, a second building block and an effective identification module.

The traveling wave detection device is installed in all substations in the power grid of the target area, and is used to record the time when the initial traveling wave generated by the fault point reaches each substation; the first building block is used to establish the time matrix T, and use the Dijkstra algorithm to calculate the fault The shortest path of traveling wave propagation, the shortest path distance matrix L is established, and the calculation matrix L' is obtained after correction; the double-ended positioning operation module is used to select the shortest path from the calculation matrix L' in turn, and select the corresponding from the time matrix T The time element uses the double-terminal positioning algorithm in the traveling wave positioning method to calculate the fault distance d _ij ; the second building block is used to judge the faulty transmission line according to the action of the circuit breaker of the protection device, and selects one end node c of the faulty transmission line as The reference node converts all fault distances d _ij to the reference node to obtain the converted fault distance d' _ij , and uses all the converted fault distances d' _ij to establish a fault distance matrix D; an effective identification module is used for fault distance matrix Validity identification of all converted fault distances d′ _ij in D, weights are set for all non-zero effective elements in fault distance matrix D, and weight matrix W is obtained, and fault distance matrix D and weight matrix W are integrated to calculate accurate fault distance d _c .

To sum up, a novel power grid fault traveling wave location method and system provided by the present invention directly establishes the fault distance matrix D by using the calculation matrix L' and the time matrix T; it does not need to perform network decompression operations on the complex ring network structure, avoiding It solves the situation that the complex ring network may not be able to solve the network, so it solves the problems of complex ring network solution network calculation and fault location failure or large location error in the grid fault traveling wave location method; at the same time, the algorithm through the effectiveness of fault distance And correction, in the case of missing or miscollected traveling wave data, the traveling wave data of the whole network can still be used to achieve accurate fault location, the realization process is simple and easy, and has broad application prospects.

In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to the present invention Thoughts, there will be changes in specific implementation methods and application ranges. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (9)

1. a kind of novel power grid functional failure travelling wave positioning method, which is characterized in that including step：

The initial traveling wave that fault point in record target area power grid generates reaches the time of all substations, settling time matrix T；

The shortest path that fault traveling wave is propagated is calculated using dijkstra's algorithm, establishes shortest path distance matrix L, after amendment To calculating matrix L '；

It chooses shortest path successively from the calculating matrix L ', and corresponding time element is chosen from the time matrix T, Fault distance d is calculated using the both-end location algorithm in travelling wave positioning method_ij；

According to the action Judging fault transmission line of electricity of protection device circuit breaker, an end node c of the faulty transmission line is chosen For reference mode, by all fault distance d_ijThe reference mode is converted, conversion fault distance d ' is obtained_ij, utilize all institutes State conversion fault distance d '_ijEstablish fault distance matrix D；

To all conversion fault distance d ' in fault distance matrix D_ijValidity identification is carried out, to owning in fault distance matrix D Weight is arranged in non-zero effective element, obtains weight matrix W, resultant fault Distance matrix D and weight matrix W, is calculated accurate Fault distance d_c。

2. a kind of novel power grid functional failure travelling wave positioning method as described in claim 1, which is characterized in that when the step is established Between matrix T include establish following time matrix T：

T=[t₁…t_i…t_n]

In formula：N is the number of substation, t₁,t₂…t_i…t_nIndicate that the initial traveling wave that fault point generates reaches substation 1 respectively, The time of 2 ... i ... n；

The step establishes shortest path distance matrix L, specifically includes step：

Assuming that sharing n node in topological structure of electric figure, access line length assigns weight matrix V as weights, construction：

Wherein：

In formula：l_ijIndicate the line length between connected node i and node j, v_ijIt is long to assign corresponding node and circuit in weight matrix V The element of degree；

According to the line length assigned in weight matrix V, the shortest path between arbitrary two node is calculated using dijkstra's algorithm, is obtained Shortest path distance matrix L：

In formula：L_ijIndicate shortest path between node i and node j by way of circuit length and.

3. a kind of novel power grid functional failure travelling wave positioning method as claimed in claim 2, which is characterized in that after the step is corrected Calculating matrix L ' is obtained, step is specifically included：

Shortest path is symmetrical matrix apart from square L, and each shortest path is undirected path, L_ij=L_ji, to avoid computing repeatedly, when When i ＜ j, L is enabled_ij=0；

When faulty line is not in looped network, by all shortest path element L without faulty line_ijIt is modified to 0, Qi Tayuan Element is without correcting；

When faulty line is in looped network, follow these steps to be modified：

1. if shortest path element L_ijTwo node is and j not in the looped network where faulty line, when shortest path does not have Have circuit in looped network when, which is modified to 0；When shortest path has circuit in looped network, judge whether shortest path wraps Containing faulty line, including when without correcting, the shortest path is disconnected from the circuit in looped network otherwise, is gone to step 4.；

2. if shortest path element L_ijTwo node is and j in the looped network where faulty line, when node i and j have one It is a when being faulty line end node, which is modified to 0；Otherwise judge whether shortest path includes faulty line, including when Without correcting, the shortest path is disconnected from the circuit in looped network when not including, is gone to step 4.；

3. if shortest path element L_ijTwo node is and j there are one in the looped network where faulty line, work as shortest path Do not have circuit in looped network when, which is modified to 0；When the shortest path and corresponding initial traveling wave arrival time pairing carry out It calculates, fault distance is approximately 0 or is approximately equal to shortest path L_ijWhen length, by L_ijElement is modified to 0；Otherwise this is most short Path disconnects from the circuit in looped network, goes to step 4.；

4. the shortest path between two node is and j is recalculated using dijkstra's algorithm, until shortest path includes faulty line Shortest path until, using the shortest path comprising faulty line as element L after calculating_ijValue；

After all elements are corrected, calculating matrix L ' is obtained.

4. a kind of novel power grid functional failure travelling wave positioning method according to claim 3, which is characterized in that the step utilizes Both-end location algorithm in travelling wave positioning method calculates fault distance d_ij, specifically include step：

Seek d_ij：

In formula：d_ijIndicate that fault point is with a distance from node i on shortest path circuit between node j in node i, L_ijIndicate node Between i and node j shortest path by way of circuit length and, v indicate fault point generate initial traveling wave on transmission line of electricity Spread speed；

The step is by all fault distance d_ijThe reference mode is converted, conversion fault distance d ' is obtained_ij, specifically include step Suddenly：

Seek d '_ij：

d′_ij=| d_ij-d_ic|

In formula：d_icIndicate the shortest distance between node i and node c.

5. a kind of novel power grid functional failure travelling wave positioning method as claimed in claim 4, which is characterized in that the step is to failure All conversion fault distance d ' in Distance matrix D_ijValidity identification is carried out, to all non-zero effective elements in fault distance matrix D Weight is set, obtains weight matrix W, resultant fault Distance matrix D and weight matrix W, accurate fault distance d is calculated_c, Specifically include step：

A conversion fault distance is chosen from fault distance matrix D, is defined asIt is owned with fault distance matrix D Convert fault distance d '_ijIt is compared as the following formula successively：

In formula：α is error threshold value；

When the number for meeting above formula is more than the half of conversion fault distance number in fault distance matrix D, it is believed that conversion event Hinder distanceEffectively；Otherwise it is assumed that it is invalid, it is substituted with 0 value；

The weighing computation method of nonzero element is in fault distance matrix D：Assuming that each effective element corresponds in fault distance matrix D In shortest path by way of substation's number be m, then can be arranged the element weight be 1/ (m-1), obtain weight matrix W；

Fault distance d_cComputational methods be：

In formula：W_ijFor fault distance matrix D effective element d_ijWeight.

6. a kind of novel power grid fault traveling wave positioning system, which is characterized in that including：

Traveling wave detector device, all substations being installed in the power grid of target area generate first for record fault point respectively The wave that begins reaches the time of each substation；

First structure module is used for settling time matrix T, and calculates the shortest path that fault traveling wave is propagated using dijkstra's algorithm Diameter establishes shortest path distance matrix L, calculating matrix L ' is obtained after amendment；

Both-end positions calculations module, for choosing shortest path successively from the calculating matrix L ', and from the time matrix T It is middle to choose corresponding time element, calculate fault distance d using the both-end location algorithm in travelling wave positioning method_ij；

It is defeated to choose the failure for the action Judging fault transmission line of electricity according to protection device circuit breaker for second structure module One end node c of electric line is reference mode, by all fault distance d_ijConvert the reference mode, obtain conversion failure away from From d '_ij, utilize all conversion fault distance d '_ijEstablish fault distance matrix D；

Effective identification module, for all conversion fault distance d ' in fault distance matrix D_ijValidity identification is carried out, pair event Hinder all non-zero effective elements in Distance matrix D and weight is set, obtains weight matrix W, resultant fault Distance matrix D and weight square Battle array W, is calculated accurate fault distance d_c。

7. a kind of novel power grid fault traveling wave positioning system as claimed in claim 6, which is characterized in that the first structure mould Block is used for：

Establish following time matrix T：

T=[t₁…t_i…t_n]

In formula：N is the number of substation, t₁,t₂…t_i…t_nIndicate that the initial traveling wave that fault point generates reaches substation 1 respectively, The time of 2 ... i ... n；

Assuming that sharing n node in topological structure of electric figure, access line length assigns weight matrix V as weights, construction：

Wherein：

In formula：l_ijIt indicates the line length between connected node i and node j, (v please be specify_ijDefinition)；

According to the line length assigned in weight matrix V, the shortest path between arbitrary two node is calculated using dijkstra's algorithm, is obtained Shortest path distance matrix L：

In formula：L_ijIndicate shortest path between node i and node j by way of circuit length and；

Shortest path is symmetrical matrix apart from square L, and each shortest path is undirected path, L_ij=L_ji, to avoid computing repeatedly, when When i ＜ j, L is enabled_ij=0；

When faulty line is not in looped network, by all shortest path element L without faulty line_ijIt is modified to 0, Qi Tayuan Element is without correcting；

When faulty line is in looped network, follow these steps to be modified：

1. if shortest path element L_ijTwo node is and j not in the looped network where faulty line, when shortest path does not have Have circuit in looped network when, which is modified to 0；When shortest path has circuit in looped network, judge whether shortest path wraps Containing faulty line, including when without correcting, the shortest path is disconnected from the circuit in looped network otherwise, is gone to step 4.；

2. if shortest path element L_ijTwo node is and j in the looped network where faulty line, when node i and j have one It is a when being faulty line end node, which is modified to 0；Otherwise judge whether shortest path includes faulty line, including when Without correcting, the shortest path is disconnected from the circuit in looped network when not including, is gone to step 4.；

3. if shortest path element L_ijTwo node is and j there are one in the looped network where faulty line, work as shortest path Do not have circuit in looped network when, which is modified to 0；When the shortest path and corresponding initial traveling wave arrival time pairing carry out It calculates, fault distance is approximately 0 or is approximately equal to shortest path L_ijWhen length, by L_ijElement is modified to 0；Otherwise this is most short Path disconnects from the circuit in looped network, goes to step 4.；

4. the shortest path between two node is and j is recalculated using dijkstra's algorithm, until shortest path includes faulty line Shortest path until, using the shortest path comprising faulty line as element L after calculating_ijValue；

After all elements are corrected, calculating matrix L ' is obtained.

8. a kind of novel power grid fault traveling wave positioning system as claimed in claim 7, which is characterized in that the both-end positioning fortune Module is calculated for seeking d_ij：

In formula：d_ijIndicate that fault point is with a distance from node i on shortest path circuit between node j in node i, L_ijIndicate node Between i and node j shortest path by way of circuit length and, v indicate fault point generate initial traveling wave on transmission line of electricity Spread speed；

The second structure module, for seeking d '_ij：

d′_ij=| d_ij-d_ic|

In formula：d_icIndicate the shortest distance between node i and node c.

9. a kind of novel power grid fault traveling wave positioning system as claimed in claim 8, which is characterized in that effective identification mould Block is used for：

A conversion fault distance is chosen from fault distance matrix D, is defined asIt is owned with fault distance matrix D Convert fault distance d '_ijIt is compared as the following formula successively：

In formula：α is error threshold value；

When the number for meeting above formula is more than the half of conversion fault distance number in fault distance matrix D, it is believed that conversion event Hinder distanceEffectively；Otherwise it is assumed that it is invalid, it is substituted with 0 value；

The weighing computation method of nonzero element is in fault distance matrix D：

Assuming that in fault distance matrix D each effective element correspond in shortest path by way of substation's number be m, then this can be set The weight of element is 1/ (m-1), obtains weight matrix W；

Fault distance d_cComputational methods be：

In formula：W_ijFor fault distance matrix D effective element d_ijWeight.