CN111157851B - Power distribution network fault positioning method and system - Google Patents

Abstract

The application provides a power distribution network fault positioning method and system, wherein the positioning method mainly comprises the following implementation steps: (1) the method comprises the steps of performing hierarchical division on a power distribution network according to a topological structure of the power distribution network; (2) establishing a 'level-section' incidence matrix and a fault current vector of the power distribution network; (3) calculating a fault judgment vector, and determining a fault occurrence point by combining a fault current vector; according to the positioning method, the power distribution network is hierarchically divided, and the hierarchical-section incidence matrix is established, so that the calculation speed can be increased and the calculation complexity can be reduced compared with the existing switch-section incidence matrix, and further the fault positioning efficiency can be improved; compared with the prior art, the hierarchical fault analysis positioning method provided by the invention has higher calculation accuracy and better performance on fault positioning accuracy.

Description

Power distribution network fault positioning method and system

Technical Field

The invention belongs to the field of power grid fault analysis, and particularly relates to a power distribution network fault positioning method and system.

Background

The power supply reliability of the power distribution system directly influences social activities of users in all aspects such as safe production, industrial operation and the like. With the promotion of new Chinese power constitution reform and the development of electric power marketization, users put higher requirements on the improvement of power supply reliability of the power distribution network. Different from a transmission network, the power distribution network is large in scale, the operation environment is complex and changeable, the power distribution network is easily influenced by people, animals and plants, weather and the like, and the possibility of the power distribution network suffering from faults is far higher than that of the transmission network. At the present stage, after a power distribution network fails, the measurement terminals at the switches on the line can upload fault information to a fault center, and the automatic main station of the power distribution network automatically performs fault location.

The prior art provides a power distribution network fault positioning method based on matrix operation, which obtains a fault judgment vector through vector operation of a 'switch-section' incidence matrix and a fault current vector of a power distribution network, thereby determining a fault occurrence point; however, the 'switch-section' incidence matrix established in the positioning method becomes increasingly complex and huge along with the complication and expansion of the power distribution network, is not beneficial to operation, increases the calculation complexity and reduces the operation speed, so that the positioning efficiency is reduced, and the troubleshooting and the clearing are not beneficial; and when more than one line of the power distribution network fails, the matrix positioning method is easy to make wrong judgment, and the fault positioning accuracy is influenced.

Disclosure of Invention

Based on the above, the invention aims to provide a power distribution network fault positioning method and system, which are used for obtaining a fault judgment vector by establishing a 'level-section' incidence matrix and carrying out vector operation on the fault judgment vector and a fault current vector, and accurately determining a fault occurrence point according to the correlation between each level in the fault judgment vector and a fault so as to make up for the defects of the existing matrix positioning method.

The invention discloses a power distribution network fault positioning method, which comprises the following steps:

dividing the power distribution network into a series of layers { K ] according to the topological structure of the power distribution network_i|i＝0,1,2,…n}；

Generating a level-section association matrix and a fault current vector;

performing vector product operation on the level-section incidence matrix and the fault current vector to obtain a fault judgment vector, wherein the fault judgment vector value M_iRepresenting a hierarchy K_iA correlation number with a fault current;

setting the number of initial fault lines as N, and judging a directional magnitude value M according to the fault_iAnd determining the number of fault lines according to the numerical relation of the fault lines and the N, and determining fault occurrence points according to the correlation between fault current flowing sections and the power distribution network level, wherein the value of the N is the number of the lines connected with the circuit breaker.

Further, dividing the power distribution network hierarchy comprises:

with the circuit breaker as a starting point, the switching nodes which are the same as the number of the sections away from the circuit breaker are divided into the same level, { K_iSubscript i in | i ═ 0,1,2, … n } represents the number of segments the switch node is from the breaker;

further, the generation process of the "level-section" incidence matrix comprises:

when distribution network level K_iAnd section I_fjWhen associated, K_iIs in line I_fjThe matrix element value of the column is 1, otherwise, 0, and the "level-section" association matrix is defined as D ═ D_ij]_n×mJ is 1,2, … m, wherein the element value d_ijRepresented by the formula

Further, the fault current vector is a column vector of m dimensions, the elements of which are defined as

Further, the failure determination vector is an n-dimensional row vector.

Further, except for M₀All the external fault judgment directional magnitudes meet M_iWhen the fault is less than or equal to 2N, the power distribution network is determined to be a single line fault, and M is removed₀Except that there is any fault judgment orientation quantity value M_iWhen 1, the single line fault occurs at M _i1 corresponds to a level K_iNear one side of the circuit breaker, the fault occurrence point is determined as the element value in the fault current vector is 1 and M _i1 corresponds to a level K_iA directly connected section near one side of the circuit breaker.

Further, when determining that the single line fault is divided by M₀All the external fault judgment directional magnitudes meet M_iWhen the single line fault is 2, the single line fault occurs at the boundary of the power distribution network, and the fault occurrence point is determined as a section which has an element value of 1 in the fault current vector and is directly connected with the boundary of the power distribution network.

Further, except for M₀Any one other fault judgment vector value satisfies M_iWhen the number of the fault lines is larger than 2N, the power distribution network is determined to be a multi-line fault, the number of the fault lines is updated in sequence from the kth vector value, and the updating formula is that N is equal to N + (M)_k-2N)，M_k+aStop updating at 2N or less, subscript k indicates first occurrence of M_iVector value position > 2N, K + a represents the vector value position for stopping updating of the number of faulty lines, a is a positive integer, and in level K_k+aThe side far away from the circuit breaker is provided with N- (2N-M)_k+a) A fault line, a fault occurrence point is determined as that the element value in the fault current vector is 1 and is equal to the level K_kOr K_k+aDirectly connected segments.

The invention also provides a power distribution network fault positioning system, which comprises:

the distribution network hierarchical division unit is used for dividing the distribution network into a series of layers { K ] according to the topological structure of the distribution network_i|i＝0,1,2,…n}；

The matrix vector generating and operating unit is used for generating a 'level-section' incidence matrix and a fault current vector and performing mathematical operation on the 'level-section' incidence matrix and the fault current vector;

and the fault occurrence point determining unit is used for determining the number of the fault lines and the specific occurrence points.

According to the technical scheme, the scheme has the following advantages:

according to the power distribution network fault positioning method and system, the power distribution network is divided in layers and the 'layer-section' incidence matrix is established, so that compared with the existing 'switch-section' incidence matrix, the calculation speed can be increased, the calculation complexity can be reduced, and the fault positioning efficiency can be further improved; compared with the prior art, the hierarchical fault analysis positioning method provided by the invention has higher calculation accuracy and better performance on fault positioning accuracy.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a flowchart illustrating an implementation of a method for locating a distribution network according to an embodiment of the present invention

Fig. 2 is a block diagram of a power distribution network positioning system according to an embodiment of the present invention

FIG. 3 shows another embodiment of the present invention for power distribution network segment I_f6Single line fault diagram

FIG. 4 shows another embodiment of the present invention for power distribution network segment I_f4Single line fault diagram

FIG. 5 shows another embodiment of the present invention for power distribution network segment I_f5And section I_f12Two-wire fault schematic

FIG. 6 shows another embodiment of the present invention for power distribution network segment I_f5And section I_f13Two-wire fault schematic

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 and fig. 2, in the embodiment, a topology structure of a distribution network is generated in a fault center 010 and transmitted to a distribution network hierarchy dividing unit 110, so as to divide the distribution network into a series of hierarchies { K }_i|i＝0,1,2,…n}；

Generating a 'level-section' incidence matrix and a fault current vector according to the divided levels and the distribution network topological structure in a matrix vector generating and calculating unit 120, and performing vector product operation on the two to obtain a fault judgment vector; the fault occurrence point determining unit 130 determines the number of fault lines and specific occurrence points according to the numerical relationship between the determination directional quantity value and the initial fault line number.

Wherein, the power distribution network is divided into the same level by using the breaker as a starting point and dividing the same number of switch nodes into the same level, wherein the switch nodes are spaced from the breaker by the same number of sections, { K {_iSubscript i in | i ═ 0,1,2, … n } represents the number of segments the switch node is from the breaker;

the "level-section" incidence matrix is defined as D ═ D_ij]_n×mJ is 1,2, … m, wherein the element value d_ijRepresented by the formula

The fault current vector is a m-dimensional column vector, and its elements are defined as

The fault decision vector is an n-dimensional row vector, the element value M_iRepresenting a hierarchy K_iA correlation number with a fault current; .

Except for M₀All the external fault judgment directional magnitudes meet M_iWhen the fault is less than or equal to 2N, the power distribution network is determined to be a single line fault, and M is removed₀Except that there is any fault judgment orientation quantity value M_iWhen 1, the single line fault occurs at M _i1 corresponds to a level K_iNear one side of the circuit breaker, the fault occurrence point is determined as the element value in the fault current vector is 1 and M _i1 corresponds to a level K_iA directly connected section near one side of the circuit breaker.

When the single line fault is determined to be divided by M₀All the external fault judgment directional magnitudes meet M_iWhen the single line fault is 2, the single line fault occurs at the boundary of the power distribution network, and the fault occurrence point is determined as a section which has an element value of 1 in the fault current vector and is directly connected with the boundary of the power distribution network.

Except for M₀Any one other fault judgment vector value satisfies M_iWhen the number of the fault lines is larger than 2N, the power distribution network is determined to be a multi-line fault, the number of the fault lines is updated in sequence from the kth vector value, and the updating formula is that N is equal to N + (M)_k-2N)，M_k+aStop updating at 2N or less, subscript k indicates first occurrence of M_iVector value position > 2N, K + a represents the vector value position for stopping updating of the number of faulty lines, a is a positive integer, and in level K_k+aThe side far away from the circuit breaker is provided with N- (2N-M)_k+a) A fault line, a fault occurrence point is determined as that the element value in the fault current vector is 1 and is equal to the level K_kOr K_k+aDirectly connected segments.

In a further embodiment, the description of the method for locating a distribution network is performed for a specific topology. Referring to fig. 3 to 6, the topology structure in the embodiment includes 1 substation, 1 breaker, 9 sectionalizers or boundary switches, and 8 line segments I_f1,I_f2,I_f3,I_f4,I_f5,I_f6,I_f12,I_f13Starting from the breaker, switches with the same number of sections away from the breaker are in the same level, and K is provided₀-K₃The total number of the fault lines in the topology structure is 4, and the number of the fault lines in the initial state of the circuit breaker is 1.

Establishing a 'level-section' incidence matrix according to the divided levels, wherein the correlation of the sections directly connected with the levels is 1, otherwise, the correlation matrix is 0

The first failure: the fault current vector is [ I ]_f1 I_f2 I_f3 I_f4 I_f5 I_f6 I_f12 I_f13]^T＝[1 0 0 1 1 1 0 0]^TThe "level-section" correlation matrix is multiplied by the fault current vector to obtain a fault decision vector [ 1222 ]]When the fault current flows through all the layers to reach the boundary of the power distribution network, the fault is judged to be a single-line fault and positioned at the boundary of the power distribution network, and the section I which has the element value of 1 and is directly connected with the boundary is combined with the fault current vector_f6I.e. the fault occurrence point, as shown in fig. 3, the position of the arrow in the figure is the fault occurrence point.

The second failure: the fault current vector is [ I ]_f1 I_f2 I_f3 I_f4 I_f5 I_f6 I_f12 I_f13]^T＝[1 0 0 1 0 0 0 0]^TThe failure determination vector is [ 1210 ]]I.e. at level K₂One side close to the breaker is in fault, and fault current does not cross over the level K₂So level K₃The correlation with the fault current is 0, and the section I is combined with the fault current vector_f4As a failure occurrence point, as shown in fig. 4, the position of the arrow in the figure is the failure occurrence point.

The third failure: the fault current vector is [ I ]_f1 I_f2 I_f3 I_f4 I_f5 I_f6 I_f12 I_f13]^T＝[1 0 0 1 1 0 1 0]^TThe failure determination vector is [ 1232 ]]I.e. updating the number of the fault lines to be 2, and the level K₃Corresponding decision vector value M₃Is 2, satisfies M₃Less than or equal to 2N, then N is updated once, and the level K₃One side far away from the circuit breaker is provided with 0 fault line, and the fault occurrence point is positioned as a section I by combining a fault current vector_f5And I_f12As shown in fig. 5, the position of the arrow in the figure is the fault occurrence point.

The fourth failure: the fault current vector is [ I ]_f1 I_f2 I_f3 I_f4 I_f5 I_f6 I_f12 I_f13]^T＝[1 0 0 1 1 0 1 1]^TThe failure determination vector is [ 1233 ]]From level K₂Starting to update the number of fault lines to 2, level K₃Stop updating at level K₃2- (2 x 2-3) ═ 1 fault current is still left on the side far away from the circuit breaker, the rear side of the hierarchy is the distribution network boundary, namely, a fault exists in the section of the distribution network boundary, and the fault occurrence point is positioned as a section I in combination with the fault current vector_f5And I_f13As shown in fig. 6, the position of the arrow in the figure is the fault occurrence point.

Compared with the prior art, the power distribution network fault positioning method provided by the embodiment improves the calculation speed and reduces the calculation complexity, and the existing positioning method is adopted to establish the 'switch-section' incidence matrix as

Taking the third failure case as an example, the failure determination vector calculated by the existing positioning method is [ I_f1 I_f2 I_f3 I_f4I_f5 I_f6 I_f12 I_f13]^T＝[0 0 0 -1 1 0 1 0]^T，

Section I occurring therein_f4The corresponding value is-1, which is an error value, and the positioning accuracy of the existing positioning method is not as high as that of the embodiment when the multi-line fault occurs, so that the embodiment has obvious advantages compared with the existing method.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (6)

1. A power distribution network fault positioning method is characterized by comprising the following steps:

dividing the power distribution network into a series of layers { K ] according to the topological structure of the power distribution network_i|i＝0,1,2,…n}；

Generating a level-section association matrix and a fault current vector;

the generation process of the 'level-section' incidence matrix comprises the following steps:

when distribution network level K_iAnd section I_fjWhen associated, K_iIs in line I_fjThe matrix element value of the column is 1, otherwise, 0, and the "level-section" association matrix is defined as D ═ D_ij]_n×mJ is 1,2, … m, wherein the element value d_ijRepresented by the formula

The fault current vector is a m-dimensional column vector, and the elements of the column vector are defined as

Performing vector product operation on the level-section incidence matrix and the fault current vector to obtain a fault judgment vector, wherein the fault judgment vector value M_iRepresenting a hierarchy K_iA correlation number with a fault current;

setting the number of initial fault lines as N, and judging a directional quantity value M according to the fault_iThe numerical relation with N confirms trouble circuit quantity to confirm the trouble emergence point according to the correlation of fault current flow section and distribution network level, and the value of N is the circuit number of connecting wire of circuit breaker, and it specifically includes:

except for M₀All the external fault judgment directional magnitudes meet M_iWhen the fault is less than or equal to 2N, the power distribution network is determined to be a single line fault, and M is removed₀Except that there is any fault judgment orientation quantity value M_iWhen 1, the single line fault occurs at M_i1 corresponds to a level K_iNear one side of the circuit breaker, the fault occurrence point is determined as the element value in the fault current vector is 1 and M_i1 corresponds to a level K_iA directly connected section near one side of the circuit breaker.

2. The distribution network fault location method of claim 1, wherein the distribution network is divided into a series of levels { K } according to the topology of the distribution network_iI ═ 0,1,2, … n } includes:

with the circuit breaker as a starting point, the switching nodes which are the same as the circuit breaker in section number are divided into the same level, { K_iThe subscript i in i ═ 0,1,2, … n } represents the number of segments the switch node is from the breaker.

3. The power distribution network fault location method of claim 1, wherein the fault decision vector is an n-dimensional row vector.

4. Method for fault location in an electric distribution network according to claim 1, characterized in that said orientation of magnitude M is determined according to said fault_iThe numerical relation with N determines the number of fault lines, and the fault occurrence point is determined according to the correlation between the fault current flowing section and the power distribution network layer, and the method further comprises the following steps:

when the single line fault is determined to be divided by M₀All the external fault judgment directional magnitudes meet M_iWhen the single line fault is 2, the single line fault occurs at the boundary of the power distribution network, and the fault occurrence point is determined as a section which has an element value of 1 in the fault current vector and is directly connected with the boundary of the power distribution network.

5. The method according to claim 1, wherein the determining the magnitude value according to the fault is performed by the power distribution network fault location methodM_iThe numerical relation with N determines the number of fault lines, and the fault occurrence point is determined according to the correlation between the fault current flowing section and the power distribution network layer, and the method further comprises the following steps:

except for M₀Any one other fault judgment vector value satisfies M_iWhen the number of the fault lines is larger than 2N, the power distribution network is determined to be a multi-line fault, the number of the fault lines is updated in sequence from the kth vector value, and the updating formula is that N is equal to N + (M)_k-2N)，M_k+aStop updating at 2N or less, subscript k indicates first occurrence of M_iVector value position > 2N, K + a represents the vector value position for stopping updating of the number of faulty lines, a is a positive integer, and in level K_k+aThe side far away from the circuit breaker is provided with N- (2N-M)_k+a) A fault line, a fault occurrence point is determined as that the element value in the fault current vector is 1 and is equal to the level K_kOr K_k+aDirectly connected segments.

6. A power distribution network fault location system for implementing the power distribution network fault location method according to any one of claims 1 to 5, comprising:

the distribution network hierarchical division unit is used for dividing the distribution network into a series of layers { K ] according to the topological structure of the distribution network_i|i＝0,1,2,…n}；

The matrix vector generating and operating unit is used for generating a 'level-section' incidence matrix and a fault current vector and performing mathematical operation on the 'level-section' incidence matrix and the fault current vector;

the generation process of the 'level-section' incidence matrix comprises the following steps:

when distribution network level K_iAnd section I_fjWhen associated, K_iIs in line I_fjThe matrix element value of the column is 1, otherwise, 0, and the "level-section" association matrix is defined as D ═ D_ij]_n×mJ is 1,2, … m, wherein the element value d_ijRepresented by the formula

The fault current vector is a m-dimensional column vector, and the elements of the column vector are defined as

A failure occurrence point determination unit for implementing the steps of:

setting the number of initial fault lines as N, and judging a directional quantity value M according to the fault_iThe numerical relation with N confirms trouble circuit quantity to confirm the trouble emergence point according to the correlation of fault current flow section and distribution network level, and the value of N is the circuit number of connecting wire of circuit breaker, and it specifically includes:

except for M₀All the external fault judgment directional magnitudes meet M_iWhen the fault is less than or equal to 2N, the power distribution network is determined to be a single line fault, and M is removed₀Except that there is any fault judgment orientation quantity value M_iWhen 1, the single line fault occurs at M_i1 corresponds to a level K_iNear one side of the circuit breaker, the fault occurrence point is determined as the element value in the fault current vector is 1 and M_i1 corresponds to a level K_iA directly connected section near one side of the circuit breaker.

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