A method and system for calculating the fault transfer capacity of a distribution network

Abstract

The present application relates to the technical field of line fault maintenance, and discloses a distribution network line fault transfer capacity calculation method and system, which obtains transferable line sections and non-transferable line sections of a fault line section, judges whether the transferable line sections are heavy load line sections according to the load redundancy value between any two towers in the transferable line sections, and records the heavy load line sections as non-transferable line sections, calculates the proportion of the number of user loads of all non-transferable line sections to the number of user loads of all line sections, calculates the proportion corresponding to all line sections of the fault point, determines the maximum proportion, and determines the transfer capacity value of the feeder according to the maximum proportion, so as to improve the accuracy of the calculation of the distribution network line fault transfer capacity by considering the situation that the line is overloaded and cannot be transferred and the number of users.

Description

Technical Field

[0001] This invention relates to the field of line fault maintenance technology, and in particular to a method and system for calculating the fault transfer capacity of distribution network lines. Background Technology

[0002] Currently, distribution network automation technology has been widely applied, and self-healing technology has been developed for power transfer to non-faulty lines after a fault. However, due to the constraints of the line network structure, there are situations where some line sections cannot transfer power at specific fault locations. To assess the extent of this inability to transfer power, there are now methods based on the proportion of loads that cannot be transferred, which can guide the optimization of the line network and improve the power transfer capacity of the lines.

[0003] Existing methods for measuring the load percentage of non-transferable line sections fail to consider two factors: first, the line's load condition (even if the electrical connection allows for transfer, there may still be situations where transfer is impossible due to overload on the opposite side); and second, comparing transfer capacity requires considering not only load but also the number of users. This reduces the accuracy of calculating the transfer capacity of distribution network lines during faults. Summary of the Invention

[0004] This invention provides a method and system for calculating the fault transfer capacity of distribution network lines, which solves the technical problem that the accuracy of the calculation of the fault transfer capacity of distribution network lines has decreased.

[0005] In view of this, the first aspect of the present invention provides a method for calculating the fault transfer capacity of a distribution network line, applied to the calculation of the fault transfer capacity of a feeder, wherein feeder switches are provided at both ends of the feeder, and multiple poles, multiple distribution network automation switches and tie switches are provided on the line between the two ends of the feeder. The distribution network automation switches and the tie switches divide the feeder into multiple line segments. The poles are also connected to multiple user terminals and other feeders. The initial switching state of the distribution network automation switches is the closed state, and the initial switching state of the tie switches is the open state. The method includes the following steps:

[0006] Obtain the transferable and non-transferable line segments of the faulty line segment, wherein the faulty line segment includes the fault point;

[0007] Calculate the load redundancy value between any two towers in the transferable line segment, and determine whether the transferable line segment is a heavily loaded line segment based on the load redundancy value. If the load redundancy value determines that the transferable line segment is a heavily loaded line segment, then record the transferable line segment as a non-transferable line segment.

[0008] Obtain the number of users in all non-transferable line segments, and calculate the ratio of the number of users in all non-transferable line segments to the total number of users in all line segments.

[0009] The fault point is set on other line segments in the feeder. The ratio of the number of user loads of all non-transferable line segments corresponding to each fault line segment to the number of user loads of all line segments is calculated to construct a ratio set.

[0010] The largest ratio is selected from the set of ratios, and the power transfer capacity value of the feeder is determined based on the largest ratio.

[0011] Preferably, the step of obtaining the transferable and non-transferable line segments of the faulty line segment, wherein the faulty line segment includes the fault point, specifically includes:

[0012] A faulty line segment is formed with the feeder switch as the starting point and the tie switch as the ending point, and the faulty line segment includes the fault point.

[0013] Based on the topology of the feeder, determine whether a non-faulty line segment is connected to the feeder switch. If it is determined that the non-faulty line segment is connected to the feeder switch, then the non-faulty line segment is recorded as a line segment that can be transferred. If it is determined that the non-faulty line segment is not connected to the feeder switch, then the non-faulty line segment is recorded as a line segment that cannot be transferred.

[0014] Preferably, the step of calculating the load redundancy value between any two towers in the transferable line segment, determining whether the transferable line segment is a heavily loaded line segment based on the load redundancy value, and recording the transferable line segment as a non-transferable line segment if the load redundancy value indicates that the transferable line segment is a heavily loaded line segment, specifically includes:

[0015] The power supply range is formed by the transferable line segment and its corresponding feeder switch, wherein the feeder switch is the upstream line segment, and the load redundancy value between any two towers in the transferable line segment is calculated.

[0016] The load redundancy value is compared with zero. If the load redundancy value is less than zero, the line segment that can be transferred and all its downstream line segments are determined to be heavy-load line segments, and the heavy-load line segments are recorded as non-transferable line segments.

[0017] Preferably, the step of selecting the largest proportion from the set of proportions and determining the feeder's transfer capacity value based on the largest proportion specifically includes:

[0018] The largest proportion is selected from the set of proportions, and the power transfer capacity of the feeder is calculated based on the largest proportion using the following formula:

[0019] k 最小转供 =1-max{k 不可转供}

[0020] In the formula, k 最小转供 The feeder's power transfer capacity value, max{k 不可转供} represents the maximum proportion.

[0021] Secondly, the present invention also provides a distribution network line fault transfer capacity calculation system, applied to the calculation of feeder fault transfer capacity, wherein feeder switches are provided at both ends of the feeder, and multiple poles, multiple distribution network automation switches and tie switches are provided on the line between the two ends of the feeder. The distribution network automation switches and the tie switches divide the feeder into multiple line segments. The poles are also connected to multiple user terminals and other feeders. The initial switching state of the distribution network automation switches is the closed state, and the initial switching state of the tie switches is the open state. The system includes:

[0022] The transfer line identification module is used to obtain the transferable and non-transferable line segments of the faulty line segment, wherein the faulty line segment includes the fault point.

[0023] The heavy-load line judgment module is used to calculate the load redundancy value between any two towers in the transferable line segment, and to determine whether the transferable line segment is a heavy-load line segment based on the load redundancy value. If the load redundancy value determines that the transferable line segment is a heavy-load line segment, then the transferable line segment is recorded as a non-transferable line segment.

[0024] The ratio calculation module is used to obtain the number of user loads for all non-transferable line segments and calculate the ratio of the number of user loads for all non-transferable line segments to the total number of user loads for all line segments.

[0025] The traversal module is used to set the fault point on other line segments in the feeder, traverse and calculate the ratio of the number of user loads of all non-transferable line segments corresponding to each fault line segment to the number of user loads of all line segments, and construct a ratio set.

[0026] The transfer capacity calculation module is used to filter out the largest proportion from the proportion set and determine the transfer capacity value of the feeder based on the largest proportion.

[0027] Preferably, the transfer line identification module specifically includes:

[0028] The fault line setting module is used to form a fault line segment starting from the feeder switch and ending at the tie switch, wherein the fault line segment includes the fault point.

[0029] The transfer identification module is used to determine whether a non-faulty line segment is connected to a feeder switch based on the topology of the feeder. If the non-faulty line segment is connected to the feeder switch, the non-faulty line segment is recorded as a transferable line segment. If the non-faulty line segment is not connected to the feeder switch, the non-faulty line segment is recorded as a non-transferable line segment.

[0030] Preferably, the heavy-load line determination module specifically includes:

[0031] The load redundancy calculation module is used to form a power supply range between the transferable line segment and its corresponding connected feeder switch, wherein the feeder switch is the upstream line segment, and to calculate the load redundancy value between any two towers in the transferable line segment.

[0032] The load redundancy comparison module is used to compare the load redundancy value with zero. If the load redundancy value is less than zero, it determines that the transferable line segment and all its downstream line segments are heavy-load line segments, and records the heavy-load line segments as non-transferable line segments.

[0033] Preferably, the power transfer capacity calculation module is specifically used to filter out the largest proportion from the proportion set, and calculate the power transfer capacity value of the feeder based on the largest proportion using the following formula:

[0034] k 最小转供 =1-max{k 不可转供}

[0035] In the formula, k 最小转供 The feeder's power transfer capacity value, max{k 不可转供} represents the maximum proportion.

[0036] As can be seen from the above technical solutions, the present invention has the following advantages:

[0037] This invention obtains the transferable and non-transferable line segments of a faulty line segment. Based on the load redundancy value between any two towers in the transferable line segment, it determines whether the transferable line segment is a heavily loaded line segment and records the heavily loaded line segment as a non-transferable line segment. By calculating the ratio of the number of users in all non-transferable line segments to the total number of users in all line segments, and calculating the proportion of the fault point in all line segments, the maximum ratio is determined. The transfer capacity value of the feeder is then determined based on the maximum ratio. This improves the accuracy of calculating the fault transfer capacity of distribution network lines by considering the cases of lines being heavily loaded and unable to transfer, as well as the number of users. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a distribution network structure with three 10kV feeders provided in an embodiment of the present invention;

[0039] Figure 2 A flowchart illustrating a method for calculating the fault transfer capacity of a distribution network line, as provided in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of a power distribution network line fault transfer capacity calculation system provided in an embodiment of the present invention. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] This invention provides a method for calculating the fault transfer capacity of a distribution network line, which is applied to the calculation of the fault transfer capacity of a feeder. The feeder is equipped with feeder switches at both ends, and multiple poles, multiple distribution network automation switches and tie switches are provided on the line between the two ends of the feeder. The distribution network automation switches and tie switches divide the feeder into multiple line segments. The poles are also connected to multiple user terminals and other feeders. The initial switch state of the distribution network automation switches is the closed state, and the initial switch state of the tie switches is the open state.

[0043] Specifically, in one example, such as Figure 1 As shown, Figure 1 The diagram illustrates a distribution network structure with three 10kV feeders. In the diagram, K1, K2, and K3 are feeder switches; F1, F2, F4, F5, F10, F9, F7, F11, F13, F14, F15, Z61, Z62, Z32, Z31, Z11, Z12, Z21, Z22, Z41, Z42, Z51, and Z52 are towers; G3 and G6 are tie switches (in the open position); and G1, G2, G4, G5, G7, and G8 are distribution network automation switches (in the closed position).

[0044] Let the load between any towers i and j be Q. ij The load redundancy is Q. Rij The rated load is Q Nij Downstream is Q Xij The number of medium and low voltage users is H ij User load W ij The load of the tower branch is included in the upstream segment. Load redundancy Q Rij =Q Nij -Q ij -Q Xij

[0045] Let F4 be the upstream and F5 the downstream. Assuming the end of the line is G3, then between F4 and G2:

[0046] Load Q F4G2 =Q F4G2 +Q XG2F5 =Q F4G2 +Q G2F5 +Q F5 +Q F5G3 =0+0+Q Z41 +Q Z42 +Q Z4n +0 Low and medium voltage users

[0047] H F4G2 =H F4G2 +H XG2F5 =H F4G2 +H G2F5 +H F5 +H F5G3 =0+0+H Z41 +H Z42 +H Z4n +0

[0048] User load

[0049] W F4G2 =W F4G2 +W XG2F5 =W F4G2 +W G2F5 +W F5 +W F5G3 =0+0+W Z41 +W Z42 +W Z4n +0

[0050] Among them W Z41 =Q Z41 *H Z41 W Z42 =Q Z42 *H Z42 W Z4n =Q Z4n *H Z4n

[0051] Load redundancy Q RF4G2 =Q NF4G2 -Q XF4G2

[0052] Let F5 be the upstream and F4 be the downstream. Assuming the end of the line is G3, then between F4 and G2:

[0053] Q G2F4 =Q G2F4 +Q XG2F4=Q G2F4 +Q F4 +Q F4G1 +Q G1F2 +Q F2 +Q F2F1 +Q F1 =0+Q Z21 +Q Z22 +Q Z2n +0+0+Q Z11 +Q Z12 +Q Z1n +0+Q Z31 +Q Z32 +Q Z3n

[0054] Number of medium and low voltage users

[0055] H G2F4 =H G2F4 +H XG2F4 =H G2F4 +H F4 +H F4G1 +H G1F2 +H F2 +H F2F1 +H F1 =0+H Z21 +H Z22 +H Z2n +0+0+H Z11 +H Z12 +H Z1n +0+H Z31 +H Z32 +H Z3n

[0056] User load

[0057] W G2F4 =W G2F4 +W XG2F4 =W G2F4 +W F4 +W F4G1 +W G1F2 +W F2 +W F2F1 +W F1 =0+W Z21 +W Z22 ++W Z2n +0+0+W Z11 +W Z12 +W Z1n +0+W Z31 +W Z32 +W Z3n

[0058] in

[0059] W Z41 =Q Z41 *H Z41 W Z42 =Q Z42 *H Z42 W Z4n =Q Z4n *H Z4n

[0060] W Z21 =Q Z21 *H Z21 W Z22 =Q Z22 *H Z22 W Z2n =Q Z2n *H Z2n

[0061] W Z31 =Q Z31 *H Z31 W Z32 =Q Z32 *H Z32 W Z3n =Q Z3n *H Z3n

[0062] Load redundancy Q RG2F4 =Q NG2F4 -Q XG2F4

[0063] Based on the aforementioned feeder distribution network, this invention provides a method for calculating the fault transfer capacity of distribution network lines, such as... Figure 2 As shown, it includes the following steps:

[0064] 101. Obtain the transferable and non-transferable line segments of the faulty line segment. The faulty line segment includes the fault point.

[0065] 102. Calculate the load redundancy value between any two towers in the transferable line segment. Determine whether the transferable line segment is a heavy-load line segment based on the load redundancy value. If the load redundancy value determines that the transferable line segment is a heavy-load line segment, then record the transferable line segment as a non-transferable line segment.

[0066] In this method, the 95th percentile of the load values ​​from the past year is selected and substituted into the calculation. If the load includes distributed generation, its load value is taken as the 95th percentile of the output values ​​from the distributed generation from the past year. If the load data is less than one year, the rated capacity of the equipment is used for calculation.

[0067] It should be noted that if N transferable paths are found, when judging the load factor, calculations should be performed for all combinations of transferable paths n=1, n=2, up to n=N.

[0068] 103. Obtain the number of user loads for all non-transferable line segments and calculate the ratio of the number of user loads for all non-transferable line segments to the total number of user loads for all line segments.

[0069] The ratio of the number of users on all non-transferable line segments to the total number of users on all line segments is as follows:

[0070] k 不可转供 =W 不可转供 / W 线路总

[0071] In the formula, k 不可转供 As a proportion, W 不可转供 W represents the number of user loads for all non-transferable line segments. 线路总 This represents the number of users across all line segments.

[0072] 104. Set the fault point on other line segments in the feeder and traverse to calculate the ratio of the number of user loads of all non-transferable line segments corresponding to each faulty line segment to the number of user loads of all line segments, and construct a ratio set.

[0073] 105. Select the largest proportion from the proportion set, and determine the feeder's power transfer capacity value based on the largest proportion.

[0074] It should be noted that the larger the maximum ratio, the greater the transfer capacity value, and the stronger the transfer capacity of feeder K.

[0075] This invention provides a method for calculating the fault transfer capacity of distribution network lines. It obtains the transferable and non-transferable line segments of a faulty line segment. Based on the load redundancy value between any two towers in the transferable line segment, it determines whether the transferable line segment is a heavily loaded line segment and records the heavily loaded line segment as a non-transferable line segment. By calculating the ratio of the number of user loads in all non-transferable line segments to the total number of user loads in all line segments, and calculating the proportion of the fault point in all line segments, the maximum ratio is determined. The transfer capacity value of the feeder is then determined based on the maximum ratio. This method improves the accuracy of calculating the fault transfer capacity of distribution network lines by considering the cases of lines being heavily loaded and unable to transfer power, as well as the number of users.

[0076] In one specific embodiment, step 101 specifically includes:

[0077] 1011. A faulty line segment is formed with the feeder switch as the starting point and the tie switch as the ending point. The faulty line segment contains the fault point.

[0078] 1012. Determine whether a non-faulty line segment is connected to the feeder switch based on the feeder topology. If the non-faulty line segment is connected to the feeder switch, record the non-faulty line segment as a line segment that can be transferred. If the non-faulty line segment is not connected to the feeder switch, record the non-faulty line segment as a line segment that cannot be transferred.

[0079] When determining whether a non-faulty line segment is connected to a feeder switch, it can be determined whether the non-faulty line segment is directly connected to the feeder switch of the faulty line segment, or connected to other feeder switches via a tie switch.

[0080] In one specific embodiment, step 102 specifically includes:

[0081] 1021. Form a power supply range by connecting the transferable line segment and its corresponding feeder switch, where the feeder switch is the upstream line segment, and calculate the load redundancy value between any two towers in the transferable line segment.

[0082] 1022. Compare the load redundancy value with zero. If the load redundancy value is less than zero, then the line segment that can be transferred and all its downstream line segments are determined to be heavy-load line segments, and the heavy-load line segments are recorded as non-transferable line segments.

[0083] Among them, the load redundancy value between any two towers in the line segment that can be transferred is used to determine whether the transfer is not possible due to load factor. If the load redundancy value of the line segment is not less than zero, it is a line segment that can be transferred, and the calculation is skipped when the fault point is located in the line segment.

[0084] In one specific embodiment, step 105 specifically includes:

[0085] After selecting the largest proportion from the set of proportions, the feeder's power transfer capacity is calculated based on the largest proportion using the following formula:

[0086] k 最小转供 =1-max{k 不可转供}

[0087] In the formula, k 最小转供 The feeder's power transfer capacity value, max{k 不可转供} represents the maximum proportion.

[0088] The above is a detailed description of an embodiment of a method for calculating the fault transfer capacity of a distribution network line provided by the present invention. The following is a detailed description of an embodiment of a system for calculating the fault transfer capacity of a distribution network line provided by the present invention.

[0089] This invention provides a system for calculating the fault transfer capacity of a distribution network line, which is applied to the calculation of the fault transfer capacity of a feeder. The feeder is equipped with feeder switches at both ends, and multiple poles, multiple distribution network automation switches and tie switches are installed on the line between the two ends of the feeder. The distribution network automation switches and tie switches divide the feeder into multiple line segments. The poles are also connected to multiple user terminals and other feeders. The initial switch state of the distribution network automation switches is the closed state, and the initial switch state of the tie switches is the open state.

[0090] Specifically, in one example, such as Figure 1 As shown, Figure 1 The diagram illustrates a distribution network structure with three 10kV feeders. In the diagram, K1, K2, and K3 are feeder switches; F1, F2, F4, F5, F10, F9, F7, F11, F13, F14, F15, Z61, Z62, Z32, Z31, Z11, Z12, Z21, Z22, Z41, Z42, Z51, and Z52 are towers; G3 and G6 are tie switches (in the open position); and G1, G2, G4, G5, G7, and G8 are distribution network automation switches (in the closed position).

[0091] Let the load between any towers i and j be Q. ij The load redundancy is Q. Rij The rated load is Q Nij Downstream is Q Xij The number of medium and low voltage users is H ij User load W ij The load of the tower branch is included in the upstream segment. Load redundancy Q Rij =Q Nij -Q ij -Q Xij

[0092] Let F4 be the upstream and F5 the downstream. Assuming the end of the line is G3, then between F4 and G2:

[0093] Load Q F4G2 =Q F4G2 +Q XG2F5 =Q F4G2 +Q G2F5 +Q F5 +Q F5G3 =0+0+Q Z41 +Q Z42 +Q Z4n +0

[0094] Number of medium and low voltage users

[0095] H F4G2 =H F4G2 +H XG2F5 =H F4G2 +HG2F5 +H F5 +H F5G3 =0+0+H Z41 +H Z42 +H Z4n +0

[0096] User load

[0097] W F4G2 =W F4G2 +W XG2F5 =W F4G2 +W G2F5 +W F5 +W F5G3 =0+0+W Z41 +W Z42 +W Z4n +0

[0098] Among them W Z41 =Q Z41 *H Z41 W Z42 =Q Z42 *H Z42 W Z4n =Q Z4n *H Z4n

[0099] Load redundancy Q RF4G2 =Q NF4G2 -Q XF4G2

[0100] Let F5 be the upstream and F4 be the downstream. Assuming the end of the line is G3, then between F4 and G2:

[0101] Q G2F4 =Q G2F4 +Q XG2F4 =Q G2F4 +Q F4 +Q F4G1 +Q G1F2 +Q F2 +Q F2F1 +Q F1 =0+Q Z21 +Q Z22 +

[0102] Q Z2n +0+0+Q Z11 +Q Z12 +Q Z1n +0+Q Z31 +Q Z32 +Q Z3n

[0103] Number of medium and low voltage users

[0104] HG2F4 =H G2F4 +H XG2F4 =H G2F4 +H F4 +H F4G1 +H G1F2 +H F2 +H F2F1 +H F1 =0+H Z21 +H Z22 +H Z2n +0+0+H Z11 +H Z12 +H Z1n +0+H Z31 +H Z32 +H Z3n

[0105] Number of user loads

[0106] W G2F4 =W G2F4 +W XG2F4 =W G2F4 +W F4 +W F4G1 +W G1F2 +W F2 +W F2F1 +W F1 =0+W Z21 +W Z22 ++W Z2n +0+0+W Z11 +W Z12 +W Z1n +0+W Z31 +W Z32 +W Z3n

[0107] wherein

[0108] W Z41 =Q Z41 *H Z41 , W Z42 =Q Z42 *H Z42 , W Z4n =Q Z4n *H Z4n

[0109] W Z21 =Q Z21 *H Z21 , W Z22 =Q Z22 *H Z22 , W Z2n =Q Z2n *H Z2n

[0110] W Z31 =Q Z31 *H Z31 W Z32 =Q Z32 *H Z32 W Z3n =Q Z3n *H Z3n

[0111] Load redundancy Q RG2F4 =Q NG2F4 -Q XG2F4

[0112] For easier understanding, please refer to Figure 3 This invention provides a power distribution network line fault transfer capacity calculation system, comprising:

[0113] The transfer line identification module 100 is used to obtain the transferable and non-transferable line sections of the faulty line section, and the faulty line section includes the fault point.

[0114] The heavy-load line judgment module 200 is used to calculate the load redundancy value between any two towers in the transferable line segment, and to determine whether the transferable line segment is a heavy-load line segment based on the load redundancy value. If the load redundancy value determines that the transferable line segment is a heavy-load line segment, then the transferable line segment is recorded as a non-transferable line segment.

[0115] The ratio calculation module 300 is used to obtain the number of user loads for all non-transferable line segments and calculate the ratio of the number of user loads for all non-transferable line segments to the total number of user loads for all line segments.

[0116] Traversal module 400 is used to set the fault point on other line segments in the feeder, traverse and calculate the ratio of the number of user loads of all non-transferable line segments corresponding to each fault line segment to the number of user loads of all line segments, and construct a ratio set.

[0117] The feeder transfer capacity calculation module 500 is used to filter out the largest proportion from the proportion set and determine the feeder transfer capacity value based on the largest proportion.

[0118] In one specific embodiment, the power transfer line identification module specifically includes:

[0119] The fault line setting module is used to form a fault line segment starting from the feeder switch and ending at the tie switch. The fault line segment contains the fault point.

[0120] The feeder transfer identification module is used to determine whether a non-faulty line segment is connected to the feeder switch based on the feeder topology. If the non-faulty line segment is connected to the feeder switch, it is recorded as a feederable line segment. If the non-faulty line segment is not connected to the feeder switch, it is recorded as a non-feederable line segment.

[0121] In one specific embodiment, the overloaded line determination module specifically includes:

[0122] The load redundancy calculation module is used to form a power supply range between the transferable line segment and its corresponding connected feeder switch, wherein the feeder switch is the upstream line segment, and calculates the load redundancy value between any two towers in the transferable line segment.

[0123] The load redundancy comparison module compares the load redundancy value with zero. If the load redundancy value is less than zero, the line segment that can be transferred and all its downstream line segments are determined to be heavy-load line segments, and the heavy-load line segments are recorded as line segments that cannot be transferred.

[0124] In one specific embodiment, the feeder transfer capacity calculation module is specifically used to filter out the largest proportion from the proportion set, and calculate the feeder transfer capacity value based on the largest proportion using the following formula:

[0125] k 最小转供 =1-max{k 不可转供}

[0126] In the formula, k 最小转供 The feeder's power transfer capacity value, max{k 不可转供} represents the maximum proportion.

[0127] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the system described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0128] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0129] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0130] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0131] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the fault transfer capacity of a distribution network line, characterized in that, This method is applied to calculate the fault transfer capacity of feeders, wherein feeder switches are installed at both ends of the feeder, and multiple poles, distribution network automation switches, and tie switches are installed on the line between the two ends of the feeder. The distribution network automation switches and tie switches divide the feeder into multiple line segments. The poles are also connected to multiple user terminals and other feeders. The initial switching state of the distribution network automation switches is the closed state, and the initial switching state of the tie switches is the open state. The method includes the following steps: Obtain the transferable and non-transferable line segments of the faulty line segment, wherein the faulty line segment includes the fault point; Calculate the load redundancy value between any two towers in the transferable line segment, and determine whether the transferable line segment is a heavily loaded line segment based on the load redundancy value. If the load redundancy value determines that the transferable line segment is a heavily loaded line segment, then record the transferable line segment as a non-transferable line segment. Obtain the number of users in all non-transferable line segments, and calculate the ratio of the number of users in all non-transferable line segments to the total number of users in all line segments; The fault point is set on other line segments in the feeder. The ratio of the number of user loads of all non-transferable line segments corresponding to each fault line segment to the number of user loads of all line segments is calculated to construct a ratio set. The largest ratio is selected from the set of ratios, and the power transfer capacity value of the feeder is determined based on the largest ratio.

2. The method for calculating the fault transfer capacity of distribution network lines according to claim 1, characterized in that, The steps of obtaining the transferable and non-transferable line segments of the faulty line segment, wherein the faulty line segment includes the fault point, specifically include: A faulty line segment is formed with the feeder switch as the starting point and the tie switch as the ending point, and the faulty line segment includes the fault point. Based on the topology of the feeder, determine whether a non-faulty line segment is connected to the feeder switch. If it is determined that the non-faulty line segment is connected to the feeder switch, then the non-faulty line segment is recorded as a line segment that can be transferred. If it is determined that the non-faulty line segment is not connected to the feeder switch, then the non-faulty line segment is recorded as a line segment that cannot be transferred.

3. The method for calculating the fault transfer capacity of distribution network lines according to claim 1, characterized in that, The steps of calculating the load redundancy value between any two towers in the transferable line segment, determining whether the transferable line segment is a heavily loaded line segment based on the load redundancy value, and recording the transferable line segment as a non-transferable line segment if the load redundancy value indicates that the transferable line segment is a heavily loaded line segment, specifically include: The power supply range is formed by the transferable line segment and its corresponding feeder switch, wherein the feeder switch is the upstream line segment, and the load redundancy value between any two towers in the transferable line segment is calculated. The load redundancy value is compared with zero. If the load redundancy value is less than zero, the line segment that can be transferred and all its downstream line segments are determined to be heavy-load line segments, and the heavy-load line segments are recorded as non-transferable line segments.

4. The method for calculating the fault transfer capacity of distribution network lines according to claim 1, characterized in that, The step of selecting the largest proportion from the set of proportions and determining the feeder's power transfer capacity value based on the largest proportion specifically includes: The largest proportion is selected from the set of proportions, and the power transfer capacity of the feeder is calculated based on the largest proportion using the following formula: k 最小转供 =1-max{k 不可转供 } In the formula, k 最小转供 The feeder's power transfer capacity value, max{k 不可转供 } represents the maximum proportion.

5. A system for calculating the fault transfer capacity of a distribution network line, characterized in that, This system is applied to calculate the fault transfer capacity of feeders. The feeder has feeder switches at both ends, and multiple poles, distribution network automation switches, and tie switches are installed along the line between the two ends. The distribution network automation switches and tie switches divide the feeder into multiple line segments. The poles also connect to multiple user terminals and other feeders. The initial switching state of the distribution network automation switches is closed, and the initial switching state of the tie switches is open. The system includes: The transfer line identification module is used to obtain the transferable and non-transferable line segments of the faulty line segment, wherein the faulty line segment includes the fault point. The heavy-load line judgment module is used to calculate the load redundancy value between any two towers in the transferable line segment, and to determine whether the transferable line segment is a heavy-load line segment based on the load redundancy value. If the load redundancy value determines that the transferable line segment is a heavy-load line segment, then the transferable line segment is recorded as a non-transferable line segment. The ratio calculation module is used to obtain the number of user loads for all non-transferable line segments and calculate the ratio of the number of user loads for all non-transferable line segments to the total number of user loads for all line segments. The traversal module is used to set the fault point on other line segments in the feeder, traverse and calculate the ratio of the number of user loads of all non-transferable line segments corresponding to each fault line segment to the number of user loads of all line segments, and construct a ratio set. The transfer capacity calculation module is used to filter out the largest proportion from the proportion set and determine the transfer capacity value of the feeder based on the largest proportion.

6. The power supply capacity calculation system for distribution network line faults according to claim 5, characterized in that, The transfer line identification module specifically includes: The fault line setting module is used to form a fault line segment starting from the feeder switch and ending at the tie switch, wherein the fault line segment includes the fault point. The transfer identification module is used to determine whether a non-faulty line segment is connected to a feeder switch based on the topology of the feeder. If the non-faulty line segment is connected to the feeder switch, the non-faulty line segment is recorded as a transferable line segment. If the non-faulty line segment is not connected to the feeder switch, the non-faulty line segment is recorded as a non-transferable line segment.

7. The power supply capacity calculation system for distribution network line faults according to claim 5, characterized in that, The heavy-load line determination module specifically includes: The load redundancy calculation module is used to form a power supply range between the transferable line segment and its corresponding connected feeder switch, wherein the feeder switch is the upstream line segment, and to calculate the load redundancy value between any two towers in the transferable line segment. The load redundancy comparison module is used to compare the load redundancy value with zero. If the load redundancy value is less than zero, it determines that the transferable line segment and all its downstream line segments are heavy-load line segments, and records the heavy-load line segments as non-transferable line segments.

8. The power supply capacity calculation system for distribution network line faults according to claim 5, characterized in that, The feeder transfer capacity calculation module is specifically used to filter out the largest proportion from the proportion set, and calculate the feeder transfer capacity value based on the largest proportion using the following formula: k 最小转供 =1-max{k 不可转供 } In the formula, k 最小转供 The feeder's power transfer capacity value, max{k 不可转供 } represents the maximum proportion.

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