Distribution network voltage type traveling wave distance measurement switch and independent device distribution method and system

Abstract

The application discloses a power distribution network voltage type traveling wave distance measurement switch and an independent device distribution point method and system, relates to the technical field of traveling wave distance measurement switch distribution points, and comprises the following steps: S1, presetting a maximum equivalent branch number; S2, determining a distribution point position of a first traveling wave distance measurement device based on a topology graph; S3, obtaining a first equivalent branch number based on the distribution point position and the topology graph, and obtaining an initial position based on the first equivalent branch number and the maximum equivalent branch number; S4, judging whether the initial position meets a distribution point rule, if yes, updating the distribution point position to the initial position, returning to S3, until the distribution point position covers a target area, and executing S5; if not, adjusting the initial position and returning to S4; and S5, distributing the traveling wave distance measurement device based on the distribution point position, solving the problems that the existing traveling wave distance measurement switch distribution point mode does not consider voltage traveling wave fast attenuation, resulting in poor traveling wave distance measurement effect, and the traveling wave distance measurement switch is not installed at the end of a line, and cannot realize fault positioning of the whole line.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of traveling wave distance measurement switch point distribution, in particular to a distribution network voltage type traveling wave distance measurement switch and an independent device point distribution method and system. BACKGROUND

[0002] In the overhead line-based distribution network, the popularization of feeder automation technology enables the arrangement of primary and secondary integrated intelligent switches (hereinafter referred to as pole-mounted switches) at important nodes. The voltage type traveling wave distance measurement switch, which is transformed on the basis of the pole-mounted switch, can capture the voltage traveling wave generated after the fault of the distribution network and cooperate with other traveling wave distance measurement switches and the like to realize fault location by using the principle of the double-end method. At present, the traveling wave distance measurement switch still refers to the point distribution scheme of the pole-mounted switch for point distribution. However, the transmission of the voltage traveling wave is affected by the length of the overhead line or cable, the number of branches, the length of the branches, the type of nodes, cable crossing and the like, and its transmission characteristics are different from the power frequency voltage. The power frequency voltage has little attenuation during transmission along the transmission line, generally within 5%, so when considering the protection of the power frequency quantity, the point distribution scheme of the existing pole-mounted switch generally does not consider voltage attenuation, but directly arranges the switch at the outlet side of the transformer substation, important branch nodes, important section nodes and the like from the perspective of protection implementation and load quantity. However, the voltage traveling wave is greatly affected by cable crossing and branching during transmission. An overhead line branch will cause a 33% attenuation, and cable crossing will cause an attenuation of more than 50%, so directly using the existing pole-mounted switch point distribution method will lead to poor traveling wave distance measurement effect in many scenarios after the fault occurs, because the voltage traveling wave has already been greatly attenuated before it reaches the switch (smaller than the minimum measurable value of the pole-mounted switch). Especially for high-resistance grounding, the initial value of the voltage traveling wave generated at the fault point is small, which leads to even poorer traveling wave distance measurement effect for high-resistance grounding faults. SUMMARY

[0003] In order to solve the problem that the existing traveling wave distance measurement switch point distribution method does not consider the fast attenuation of the voltage traveling wave, leading to poor traveling wave distance measurement effect, the present application provides a distribution network voltage type traveling wave distance measurement switch and an independent device point distribution method, which comprises the following steps:

[0004] S1, presetting a point distribution rule and a maximum equivalent branch number N, N being an integer greater than or equal to 1;

[0005] S2, acquiring a topological graph of a target area and determining the point distribution position of a first traveling wave distance measurement device based on the topological graph;

[0006] S3, obtaining a plurality of first nodes based on the distribution position and the topology graph, calculating a first equivalent branch number M of each of the first nodes based on the distribution position, obtaining a plurality of second nodes based on the first equivalent branch number M and the maximum equivalent branch number N, obtaining an initial position based on the second nodes and a maximum value of the first equivalent branch number M, and M being a positive number;

[0007] S4, judging whether the initial position satisfies the distribution rule, if yes, updating the distribution position to the initial position, returning to the S3, until the distribution position covers the target area, and executing the S5; if not, adjusting the initial position to obtain an adjusted position, updating the initial position to the adjusted position, and returning to the S4;

[0008] S5, distributing the traveling wave distance measurement device based on the distribution position.

[0009] The method creates equivalent branches to represent various scenarios in the transmission process of the voltage traveling wave, and selects the distribution position by using the equivalent branches. Each type of factor affecting the attenuation of the voltage traveling wave can be represented by the equivalent branches, so that the attenuation of the voltage traveling wave can be simply quantified and represented, and the voltage traveling wave distance measurement switch and the independent device can be accurately distributed, thereby improving the traveling wave distance measurement effect.

[0010] Further, in the S1, the distribution rule comprises:

[0011] A, a first distance between the distribution position and a connection point of the cable and the overhead line is greater than or equal to a first threshold value;

[0012] B, a second distance between adjacent distribution positions is less than a second threshold value.

[0013] Since the voltage traveling wave is severely attenuated when being close to the connection point of the cable and the overhead line, in order to minimize the attenuation, the distribution position should be at least a certain distance away from the connection point of the cable and the overhead line (including the scenarios of cable branching and cable crossing). In order to ensure that most cases can be successfully paired once according to the millisecond time scale of the recording file during double-end distance measurement, and in order to leave a certain margin for adding branches to the line, the maximum distance between the distribution positions cannot exceed a certain distance.

[0014] Further, in the S1, the maximum equivalent branch number N is obtained in the following manner:

[0015] A ground fault with a preset maximum threshold value of ohms occurs at a traveling wave distance measurement switch, a voltage measurement value and a minimum voltage value of the traveling wave distance measurement switch are obtained, and the maximum equivalent branch number N is obtained based on the voltage measurement value and the minimum voltage value;

[0016] The calculation formula of the maximum equivalent branch number N is:

[0017] ;

[0018] wherein, denotes a margin coefficient, denotes a minimum voltage value, denotes a voltage measurement value.

[0019] Since a complete T-branch will make the voltage traveling wave attenuate to 67%, the method converts all cases into complete T-branch, at the same time, it is necessary to ensure that the device can still collect and have a certain margin when the fault occurs at the farthest end of the protection interval after the point is distributed, therefore, the calculation of the maximum equivalent branch number N of the method is simple and clear, which is convenient for field application.

[0020] Further, the specific steps of determining the point distribution position of the first traveling wave distance measurement device in S2 include:

[0021] If the substation is externally connected to a cable outlet, and a traveling wave distance measurement switch is preset to be installed at the cable outlet, then the point distribution position of the first traveling wave distance measurement device is obtained based on the cable outlet;

[0022] If the substation is not externally connected to a cable outlet, then the point distribution position of the first traveling wave distance measurement device is obtained based on the point distribution rule.

[0023] If the substation is externally connected to a cable outlet, and a traveling wave distance measurement switch must be installed at the outlet, then the point is distributed at this position; otherwise, under the premise of meeting the point distribution rule A, the first point should be as close as possible to the substation outlet side to ensure that the distance measurement effect covers the whole network.

[0024] Further, in S3, the first equivalent branch number M is obtained in the following manner:

[0025] Based on the topology graph, the node area from the point distribution position to each first node is obtained, the node lines of the node area are divided, a plurality of topology structures are obtained, and each topology structure corresponds to a different equivalent branch conversion manner;

[0026] The line length of each topology structure is obtained, and based on the line length and the equivalent branch conversion manner, the second equivalent branch number of each topology structure is obtained;

[0027] The second equivalent branch numbers are superimposed to obtain the first equivalent branch number M of each first node.

[0028] Because different topologies have different attenuation effects on voltage traveling waves, different topologies adopt different equivalent branch conversion methods, which can convert complex attenuation calculation work into simple branch conversion work, facilitate reliable application on site, and convert from the upstream to the downstream, and adopt different conversion strategies when different topologies are encountered.

[0029] Further, the specific step of obtaining the initial position in S3 further comprises:

[0030] S301, based on the downstream direction of the distribution network line, obtaining the second node adjacent to the initial position, and obtaining the node position;

[0031] S302, based on the node position, the point position, and the acquisition mode of the first equivalent branch number M, calculating the third equivalent branch number M1 of the node position;

[0032] S303, if the maximum value of the first equivalent branch number M is less than the maximum equivalent branch number N, and the third equivalent branch number M1 is greater than the maximum equivalent branch number N, it is determined that the initial position is a point position; if the condition is not met, return to S301, update the initial position to the node position, and update the maximum value of the first equivalent branch number M to the third equivalent branch number M1.

[0033] Further, in S4, the judgment mode of the point position covering the target area is:

[0034] If the point position has been set to the end of the trunk line and the end of the branch in the fault positioning section, it is determined that the point position covers the target area.

[0035] Further, in S4, the specific step of obtaining the adjustment position comprises:

[0036] S401, based on the upstream direction of the distribution network line, obtaining the second node adjacent to the initial position, and obtaining the adjacent position;

[0037] S402, judging whether the adjacent position meets the point rule, if yes, obtaining the adjustment position based on the adjacent position, if no, returning to S401, and updating the initial position to the adjacent position.

[0038] The traveling wave distance measurement switch is an upgrade of the pole-mounted switch, that is, the traveling wave distance measurement switch must have the function of the pole-mounted switch. The pole-mounted switch in the distribution network mainly plays the role of protecting a section of line, and there is no line at the end. Therefore, except for special switches that bear the functions of tie switches and network source switches, pole-mounted switches are generally not installed at the end of the line, which makes the existing arrangement of traveling wave distance measurement switches unable to realize fault positioning for the entire line.

[0039] Further, in S5, the traveling wave distance measurement device comprises a traveling wave distance measurement switch and a stand-alone device, and the specific steps of arranging the traveling wave distance measurement device based on the arrangement position comprise:

[0040] determining whether the arrangement position satisfies the following conditions simultaneously:

[0041] Condition 1: the arrangement position satisfies the installation condition of the traveling wave distance measurement switch;

[0042] Condition 2: the arrangement position satisfies the arrangement principle of the power distribution network switch;

[0043] Condition 3: the arrangement position is not the end of the line;

[0044] If the above conditions are satisfied simultaneously, the arrangement position is arranged with the traveling wave distance measurement switch, and if the conditions are not satisfied, the arrangement position is arranged with the stand-alone device.

[0045] The method provides a power distribution network voltage type traveling wave distance measurement switch and a stand-alone device, the stand-alone device is installed at the end of the line, the stand-alone device is used to collect fault traveling wave signals, and fault positioning of the whole line is realized.

[0046] The application further provides a power distribution network voltage type traveling wave distance measurement switch and stand-alone device arrangement system, the system comprises:

[0047] a data unit: used for presetting an arrangement rule and a maximum equivalent branch number N, obtaining a topology graph of a target area, and N is an integer greater than or equal to 1;

[0048] a starting point unit: used for determining an arrangement position of a first traveling wave distance measurement device based on the topology graph;

[0049] an initial unit: used for obtaining a plurality of first nodes based on the arrangement position and the topology graph, calculating a first equivalent branch number M of each first node based on the arrangement position, obtaining a plurality of second nodes based on the first equivalent branch number M and the maximum equivalent branch number N, and obtaining an initial position based on the second nodes and the maximum value of the first equivalent branch number M, and M is a positive number;

[0050] an analysis unit: used for determining whether the initial position satisfies the arrangement rule, updating the arrangement position to the initial position if the arrangement rule is satisfied, returning to the initial unit until the arrangement position covers the target area, and executing S5; and adjusting the initial position if the arrangement rule is not satisfied, obtaining an adjusted position, updating the initial position to the adjusted position, and returning to the analysis unit;

[0051] an arrangement unit: used for arranging the traveling wave distance measurement device based on the arrangement position.

[0052] The principle and effect of the system are similar to the method, and no corresponding description is made for the system.

[0053] The one or more technical solutions provided by the application have at least the following technical effects or advantages:

[0054] The method creates equivalent branches to represent each scene in the voltage wave transmission process, selects the point position by using the equivalent branches, considers the voltage wave attenuation, improves the effect of wave distance measurement, provides a distribution network voltage type wave distance measurement switch and an independent device, installs the independent device to the end of the line, collects the fault wave signal by using the independent device, and realizes fault positioning of the whole line. BRIEF DESCRIPTION OF DRAWINGS

[0055] The accompanying drawings described herein are used to provide a further understanding of the embodiments of the application, constitute a part of the application, and do not constitute a limitation on the embodiments of the application;

[0056] Figure 1 is a flowchart of the point distribution method of the distribution network voltage type wave distance measurement switch and the independent device in the application;

[0057] Figure 2 is a specific flowchart of obtaining the initial position;

[0058] Figure 3 is a structural schematic diagram of a 10kV distribution network topology diagram;

[0059] Figure 4 is a point distribution position schematic diagram of a 10kV distribution network topology diagram. DETAILED DESCRIPTION

[0060] In order to more clearly understand the above-mentioned purposes, features and advantages of the application, the application will be further described in detail below in combination with the drawings and specific embodiments. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other without conflict.

[0061] In the following description, many specific details are set forth in order to provide a thorough understanding of the application, however, the application can also be implemented in other ways different from the scope described herein, therefore, the protection scope of the application is not limited by the specific embodiments disclosed below.

[0062] Embodiment one

[0063] Reference Figures 1-2 The embodiment provides a point distribution method of a distribution network voltage type wave distance measurement switch and an independent device, and the method comprises:

[0064] S1, presetting a point distribution rule and a maximum equivalent branch number N, N is an integer greater than or equal to 1;

[0065] The distribution rules include:

[0066] A. The first distance between the distribution position and the connection point of the cable and overhead line (including the scenarios of cable branch and cable crossing) is greater than or equal to a first threshold value; in this embodiment, the first threshold value is at least 300 meters, and is most preferably 500 meters. The 300 meters can ensure that the voltage traveling wave is not affected by the connection point, and the 500 meters can ensure that the voltage traveling wave is not affected by the connection point at all.

[0067] B. The second distance between adjacent distribution positions is less than a second threshold value. In this embodiment, the second threshold value is most preferably 6 km. Considering that the traveling wave propagation speed is 3x10 8 meters per second, the maximum interval between control points is not more than 6 km, which can ensure that the maximum time difference of double-end distance measurement is 0.02 ms. The recording file generated by the pole-mounted switch has a millisecond-level time mark, and in most cases, distance measurement can be directly performed by pairing the time mark. Controlling within 6 km can ensure that even in the extreme case of boundary distance measurement, there is still a high probability of one-time pairing success directly through the file name time mark, and only a small number of cases need to be verified and paired twice, which can improve the speed of traveling wave distance measurement. At the same time, 6 km is approximately 100-level towers in the field, and if the span between two points exceeds 100-level towers, the line needs to be modified and branched, and the margin is not enough, which will lead to poor distance measurement effect after branching.

[0068] The maximum equivalent branch number N is obtained in the following manner:

[0069] A ground fault with a preset maximum threshold value of ohms occurs at a traveling wave distance measurement switch, and the voltage measurement value and the minimum voltage value of the traveling wave distance measurement switch are obtained. The maximum equivalent branch number N is obtained based on the voltage measurement value and the minimum voltage value. In this embodiment, the maximum threshold value of ohms determines the size of the voltage measurement value, which can generally be determined by simulation and experiment to determine the relationship between the maximum threshold value of ohms and the voltage measurement value.

[0070] The calculation formula of the maximum equivalent branch number N is:

[0071] ;

[0072] wherein, is a margin coefficient, which can be selected according to the stability and accuracy of the actual device, and in a common case, it can be taken as 1.2, is a minimum voltage value, is a voltage measurement value, which is the size of the voltage traveling wave measured by the sensor when the maximum threshold value of ohms grounding occurs on the traveling wave distance measurement switch (or at the equivalent node).

[0073] S2, obtaining a topology graph of the target area, and determining a first location of the traveling wave fault location device based on the topology graph;

[0074] The specific steps of determining the first location of the traveling wave fault location device include:

[0075] If the substation is externally connected with a cable outlet, and a traveling wave fault location switch is preset to be installed at the cable outlet, the first location of the traveling wave fault location device is obtained based on the cable outlet; and it is considered that there is a cable branch with a length of the length of the external cable, and the branch should be converted when subsequent locations are determined (conversion method is shown in S3).

[0076] If the substation is not externally connected with a cable outlet, the first location of the traveling wave fault location device is obtained based on the location rule. On the premise of meeting the location rule A, the first location should be as close to the outlet side of the substation as possible to ensure that the fault location effect covers the whole network.

[0077] S3, obtaining a plurality of first nodes based on the location and the topology graph, calculating a first equivalent branch number M of each first node based on the location, and obtaining a plurality of second nodes based on the first equivalent branch number M and the maximum equivalent branch number N, that is, selecting the first node with the first equivalent branch number M less than the maximum equivalent branch number N to obtain the second node.

[0078] The initial location is obtained based on the second node and the maximum value of the first equivalent branch number M. The first node with the first equivalent branch number M less than the maximum equivalent branch number N and the maximum first equivalent branch number M is selected to obtain the initial location, which can ensure that the number of points is as small as possible, the cost and the number of live working installation are as small as possible, and M is a positive number.

[0079] The first equivalent branch number M is obtained in the following manner:

[0080] The node area from the location to each first node is obtained based on the topology graph, the node line of the node area is divided, and a plurality of topology structures are obtained, each of which corresponds to a different equivalent branch conversion method. In this embodiment, the equivalent branch conversion methods of different topology structures are shown in Table 1:

[0081] Table 1: Equivalent branch conversion methods of different topology structures

[0082]

[0083] The line length of each topology structure is obtained, and the second equivalent branch number of each topology structure is obtained based on the line length and the equivalent branch conversion method.

[0084] Superimpose the second equivalent branch number to obtain the first equivalent branch number M of each first node.

[0085] Wherein, the specific steps of obtaining the initial position further comprise:

[0086] S301, based on the downlink direction of the power distribution network line, obtaining the second node adjacent to the initial position, obtaining the node position;

[0087] S302, based on the node position, the distribution position and the acquisition method of the first equivalent branch number M, using the same equivalent branch conversion method as shown in Table 1, calculating the third equivalent branch number M1 of the node position;

[0088] S303, if the maximum value of the first equivalent branch number M is less than the maximum equivalent branch number N, and the third equivalent branch number M1 is greater than the maximum equivalent branch number N, it is determined that the initial position is the distribution position; if the condition is not met, return to S301, update the initial position to the node position, and update the maximum value of the first equivalent branch number M to the third equivalent branch number M1.

[0089] S4, judging whether the initial position meets the distribution rule, if yes, updating the distribution position to the initial position, returning to S3, until the distribution position covers the target area, and executing S5; if not, adjusting the initial position to obtain an adjusted position, updating the initial position to the adjusted position, and returning to S4;

[0090] Wherein, the judgment method of the distribution position covering the target area is:

[0091] If the distribution position has been set to the branch end of the trunk line end and the fault positioning section, it is determined that the distribution position covers the target area. If all points have been set to the end of the trunk line and the end of the fault positioning branch, stop.

[0092] Wherein, the specific steps of obtaining the adjusted position comprise:

[0093] S401, based on the uplink direction of the power distribution network line, obtaining the second node adjacent to the initial position, obtaining an adjacent position;

[0094] S402, judging whether the adjacent position meets the distribution rule, if yes, obtaining an adjusted position based on the adjacent position, if not, returning to S401, updating the initial position to the adjacent position.

[0095] S5, based on the distribution position, setting the traveling wave distance measurement device.

[0096] The traveling wave distance measurement device comprises a traveling wave distance measurement switch and a separate device, and the specific steps of arranging the traveling wave distance measurement device based on the arrangement position comprise:

[0097] It is determined whether the arrangement position satisfies the following conditions simultaneously:

[0098] Condition 1: The arrangement position satisfies the installation condition of the traveling wave distance measurement switch, for example, the installation condition of the traveling wave distance measurement switch can comprise: the arrangement position needs to be a main section point or a branch point.

[0099] Condition 2: The arrangement position satisfies the arrangement principle of the power distribution network switch, for example, the arrangement principle of the power distribution network switch can comprise: the arrangement position needs to have the demand of splitting and closing a heavy load; the power distribution network switch is a switch device used for distributing electric energy.

[0100] Condition 3: The arrangement position is not a line end, that is, all end points are arranged with separate devices.

[0101] If the above conditions are satisfied simultaneously, the arrangement position is arranged with the traveling wave distance measurement switch, and if the conditions are not satisfied, the arrangement position is arranged with the separate device.

[0102] The separate device refers to a device without the functions of splitting and closing, and only with the function of voltage traveling wave detection.

[0103] Embodiment Two

[0104] Reference Figures 2-4 , wherein, Figures 3-4 In the figure, the black nodes represent towers, the numbers with # represent the tower serial numbers, the connecting lines between the nodes represent transmission lines, the numbers on the connecting lines represent the lengths of the transmission lines (unit: meter), the solid lines represent that the transmission lines are overhead lines, the dashed lines represent that the transmission lines are cables, and the intervals for which fault positioning is expected to be achieved are 1# to 43# and the branch of 33#.

[0105] On the basis of Embodiment One, this embodiment illustrates the process of arranging the traveling wave distance measurement device:

[0106] S1, presetting an arrangement rule and a maximum equivalent branch number N, N is an integer greater than or equal to 1;

[0107] The arrangement rule comprises:

[0108] A, the arrangement position is at least 300 meters (preferably 500 meters) away from the connection point of the cable and the overhead line (including the scene of cable branch and cable crossing);

[0109] B, the maximum interval between adjacent arrangement positions is less than 6km.

[0110] The maximum equivalent branch number N is obtained in the following manner:

[0111] In this embodiment, to locate a ground fault with a maximum of 5000 ohms, a ground fault with a preset maximum threshold of 5000 ohms is set. The ground fault occurs at the traveling wave distance measuring switch, and the voltage measurement value and the minimum voltage value of the traveling wave distance measuring switch are obtained; based on the voltage measurement value and the minimum voltage value, the maximum equivalent branch number N is obtained; let = 893 mV, = 150 mV, = 1.2. According to the calculation formula of the maximum equivalent branch number N, N .

[0112] S2. Obtain the topology map of the target area, and determine the layout position of the first traveling wave distance measuring device based on the topology map;

[0113] Among them, the specific steps for determining the layout position of the first traveling wave distance measuring device include:

[0114] If there is an external cable outlet at the substation and a traveling wave distance measuring switch is preset at the cable outlet, the layout position of the first traveling wave distance measuring device is obtained based on the cable outlet; and it is considered that there is a cable branch with a length equal to the length of the external cable at this layout position, and this branch should be converted during subsequent layout (the conversion method is shown in S3);

[0115] If there is no external cable outlet at the substation, the layout position of the first traveling wave distance measuring device is obtained based on the layout rule. On the premise of meeting the layout rule A, to ensure that the ranging effect covers the entire network, the first layout should be as close as possible to the outgoing line side of the substation. Assume that the first layout position is arranged at the pole G0 according to the above method.

[0116] In this embodiment, pole 1# is the closest to the outgoing line side of the substation, so the first point is arranged at pole 1#.

[0117] S3. Starting from the first layout position, calculate the equivalent branch number M backward, and take the position where M < N and M is as large as possible as the preliminary layout position. Specifically: Based on the layout position and the topology map, several first nodes are obtained, the first equivalent branch number M of each first node is calculated based on the layout position, based on the first equivalent branch number M and the maximum equivalent branch number N, several second nodes are obtained, and the nodes with M < N among the first nodes are selected to obtain the second nodes;

[0118] Based on the second node and the maximum value of the first equivalent branch number M, the initial position is obtained, that is, the node where M < N and M is the largest is designated as the initial position.

[0119] Among them, the method for obtaining the first equivalent branch number M is:

[0120] The node area from the distribution point position to each first node is obtained based on the topological graph, the node line of the node area is divided, and a plurality of topological structures are obtained, each of which corresponds to a different equivalent branch conversion mode;

[0121] The line length of each topological structure is obtained, and the second equivalent branch number of each topological structure is obtained based on the line length and the equivalent branch conversion mode;

[0122] The first equivalent branch number M of each first node is obtained by superimposing the second equivalent branch number.

[0123] From G0(1#) to the downstream conversion, different conversion modes are used for different topological structures, and the specific conversion mode is shown in Table 1.

[0124] In this embodiment, the branches at 11#, 21#, 22#, 25# and 33# are equivalent to 1, 1, 0.3, 0.3 and 1 equivalent branches respectively, 1# to 25# is about 4km, which is equivalent to 0.8 equivalent branches, 25# to 33# has 1257.32m, which is equivalent to 0.25 equivalent branches, 33# to 42# has 1330.73m, which is equivalent to 0.27 equivalent branches, 60.05m cable passes through, which is equivalent to 3 equivalent branches, and 60.05m cable itself is equivalent to 0.025 branches.

[0125] The total equivalent branch number from 1# to 25# is: 1+1+0.3+0.3+0.8=3.4<4;

[0126] The total equivalent branch number from 1# to 33# is: 1+1+0.3+0.3+1+0.8+0.25=4.65>4; Therefore, a point should be distributed between 25# and 33#.

[0127] The total equivalent branch number of other nodes is calculated in the same way.

[0128] The specific steps of obtaining the initial position further include:

[0129] S301, based on the downward direction of the distribution network line, a second node adjacent to the initial position is obtained, and a node position is obtained;

[0130] S302, based on the node position, the distribution point position and the acquisition mode of the first equivalent branch number M, the same equivalent branch conversion mode is used to calculate the third equivalent branch number M1 of the node position, as shown in Table 1.

[0131] S303, if the maximum value of the first equivalent branch number M is less than the maximum equivalent branch number N, and the third equivalent branch number M1 is greater than the maximum equivalent branch number N, it is determined that the initial position is the point position; if the condition is not met, return to S301, update the initial position to the node position, and update the maximum value of the first equivalent branch number M to the third equivalent branch number M1.

[0132] If the next point position is arranged at the tower G1, M=M1; if the next point position is arranged at the tower G2 (G2 is adjacent to G1), M=M2, and the following conditions are met:

[0133]

[0134] The next point position is arranged at the tower G1, and if not, G1 is moved to G2, and the above steps are repeated until the condition is met.

[0135] S4, determine whether the initial position meets the point arrangement rule, if it meets, update the point position to the initial position, return to S3, until the point position covers the target area, and execute S5; if it does not meet, adjust the initial position to obtain an adjusted position, update the initial position to the adjusted position, and return to S4;

[0136] The judgment method of the point position covering the target area is as follows:

[0137] If the point position has been arranged to the end of the trunk line and the end of the branch of the fault positioning section, it is determined that the point position covers the target area. If all points have been arranged to the end of the trunk line and the end of the branch of the fault positioning section, stop.

[0138] The specific steps of obtaining the adjusted position include:

[0139] S401, based on the upstream direction of the distribution network line, a second node adjacent to the initial position is obtained, and an adjacent position is obtained;

[0140] S402, determine whether the adjacent position meets the point arrangement rule, if yes, obtain the adjusted position based on the adjacent position, if no, return to S401, and update the initial position to the adjacent position.

[0141] If G1 violates the point arrangement rule, move one tower in the direction of G0 to G 11 (G 11 Adjacent to G1), see if it still violates the point arrangement rule, if yes, continue to move in the direction of G0, and repeat the verification until a tower G 111 is found which does not violate the point arrangement rule, and the next point position is finally determined to be arranged at the tower G 111 .

[0142] ​In this embodiment, the points between 25# and 33# do not violate the point distribution principle, and finally a point is determined to be distributed between 25# and 33#. From the economic point of view, it is distributed at 25#.

[0143] S3-S4 is repeated, and the finally obtained point distribution scheme is shown in Figure 4

[0144] S5, based on the point distribution position, arranging the traveling wave distance measuring device.

[0145] The traveling wave distance measuring device includes a traveling wave distance measuring switch and an independent device, and the specific steps of arranging the traveling wave distance measuring device based on the point distribution position include:

[0146] determine whether the point distribution position meets the following conditions at the same time:

[0147] Condition 1, the point distribution position has the installation condition of the traveling wave distance measuring switch;

[0148] Condition 2, the point distribution position meets the point distribution principle of the power distribution network switch;

[0149] Condition 3, the point distribution position is not the end of the line, that is, all end points are arranged with independent devices.

[0150] If the above conditions are met at the same time, the point distribution position is arranged with the traveling wave distance measuring switch, and if not, the point distribution position is arranged with the independent device.

[0151] In this embodiment, the point distribution 1, the point distribution 2, the point distribution 3 and the point distribution 5 are arranged with the traveling wave distance measuring switch, and the point distribution 4, the point distribution 6, the point distribution 7 and the point distribution 8 are arranged with the independent device.

[0152] Example three

[0153] On the basis of the above-mentioned embodiments, the power distribution network voltage type traveling wave distance measuring switch and independent device point distribution system is also provided, the system includes:

[0154] Data unit: for presetting point distribution rules and maximum equivalent branch number N, obtaining the topology graph of the target area, N is an integer greater than or equal to 1;

[0155] Starting point unit: for determining the point distribution position of the first traveling wave distance measuring device based on the topology graph;

[0156] Initial unit: for obtaining a plurality of first nodes based on the point distribution position and the topology graph, calculating the first equivalent branch number M of each first node based on the point distribution position, obtaining a plurality of second nodes based on the first equivalent branch number M and the maximum equivalent branch number N, and obtaining the initial position based on the second node and the maximum value of the first equivalent branch number M, M is a positive number; ​

[0157] the initial position is adjusted to obtain an adjusted position, the initial position is updated as the adjusted position, and the analysis unit is returned;

[0158] the initial position is adjusted to obtain an adjusted position, the initial position is updated as the adjusted position, and the analysis unit is returned;

[0159] While the preferred embodiments of the application have been described, additional modifications and changes can occur to those skilled in the art once they learn of the basic creative principles disclosed herein. Accordingly, it is intended that the present application be construed as including all such modifications and changes as fall within the scope of the appended claims.

[0160] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method for deploying voltage-type traveling wave ranging switches and independent devices in power distribution networks, characterized in that, The method includes: S1, Preset point placement rules and maximum equivalent branch number N, where N is an integer greater than or equal to 1; S2. Obtain a topology map of the target area, and determine the location of the first traveling wave ranging device based on the topology map; S3. Based on the location of the nodes and the topology, obtain a number of first nodes. Calculate the first equivalent branch number M for each first node based on the location of the nodes. Based on the first equivalent branch number M and the maximum equivalent branch number N, obtain a number of second nodes. Obtain the initial position based on the maximum value of the second nodes and the first equivalent branch number M, where M is a positive number. S4. Determine whether the initial position satisfies the placement rule. If it does, update the placement position to the initial position and return to S3 until the placement position covers the target area, then execute S5. If it does not satisfy the rule, adjust the initial position to obtain the adjusted position, update the initial position to the adjusted position, and return to S4. S5. Deploy the traveling wave ranging device based on the specified deployment locations. In step S3, the first equivalent branch number M is obtained as follows: Based on the topology map, the node region from the point location to each first node is obtained, the node lines of the node region are divided, and several topology structures are obtained. Each topology structure corresponds to a different equivalent branch conversion method. Obtain the line length of each topology, and based on the line length and the equivalent branch conversion method, obtain the second equivalent branch number of each topology; The first equivalent branch number M for each first node is obtained by superimposing the second equivalent branch number. In step S3, the specific steps for obtaining the initial position further include: S301. Based on the downlink direction of the distribution network line, obtain the second node adjacent to the initial position to obtain the node position; S302. Based on the node position, the placement position, and the method of obtaining the first equivalent branch number M, calculate the third equivalent branch number M1 of the node position; S303. If the maximum value of the first equivalent branch number M is less than the maximum equivalent branch number N, and the third equivalent branch number M1 is greater than the maximum equivalent branch number N, then the initial position is determined as the placement position; if the conditions are not met, then return to S301, update the initial position to the node position, and update the maximum value of the first equivalent branch number M to the third equivalent branch number M1.

2. The method for deploying voltage-type traveling wave ranging switches and independent devices in a distribution network according to claim 1, characterized in that, In S1, the point placement rules include: The first distance between the location of the sampling point and the connection point of the cable and overhead line is greater than or equal to a first threshold. The second spacing between adjacent placement points is less than the second threshold.

3. The method for deploying voltage-type traveling wave ranging switches and independent devices in a distribution network according to claim 1, characterized in that, In S1, the maximum equivalent branch number N is obtained as follows: A ground fault with a preset maximum threshold ohm is identified, where the ground fault occurs at a traveling wave ranging switch. The voltage measurement value and minimum voltage value of the traveling wave ranging switch are obtained. Based on the voltage measurement value and the minimum voltage value, the maximum equivalent branch number N is obtained. The formula for calculating the maximum equivalent branch number N is: ； in, Represents the margin coefficient. Indicates the minimum voltage value. This indicates the measured voltage value.

4. The method for deploying voltage-type traveling wave ranging switches and independent devices in a distribution network according to claim 1, characterized in that, In step S2, the specific steps for determining the location of the first traveling wave ranging device include: If the substation has an external cable outlet, and a traveling wave ranging switch is pre-installed at the cable outlet, then the location of the first traveling wave ranging device is obtained based on the cable outlet. If the substation does not have an external cable outlet, the location of the first traveling wave ranging device is obtained based on the aforementioned placement rules.

5. The method for deploying voltage-type traveling wave ranging switches and independent devices in a distribution network according to claim 1, characterized in that, In step S4, the method for determining whether the placement location covers the target area is as follows: If the deployment points have been deployed to the end of the main line and the end of the branch of the fault location section, then it is determined that the deployment points cover the target area.

6. The method for deploying voltage-type traveling wave ranging switches and independent devices in a distribution network according to claim 1, characterized in that, In step S4, the specific steps for obtaining the adjusted position include: S401. Based on the uplink direction of the distribution network line, obtain the second node adjacent to the initial position to obtain the adjacent position; S402. Determine whether the adjacent positions satisfy the point layout rules. If yes, obtain the adjusted position based on the adjacent positions. Otherwise, return to S401 and update the initial position to the adjacent positions.

7. The method for deploying voltage-type traveling wave ranging switches and independent devices in a distribution network according to claim 1, characterized in that, In step S5, the traveling wave ranging device includes a traveling wave ranging switch and an independent device. The specific steps for deploying the traveling wave ranging device based on the location of the sampling point include: Determine whether the location of the points simultaneously meets the following conditions: Condition 1: The location of the sampling point meets the installation requirements of the traveling wave ranging switch; Condition 2: The locations of the distribution points comply with the distribution network switch placement principles; Condition 3: The location of the sampling point is not at the end of the line; If all of the above conditions are met, the traveling wave ranging switch is installed at the designated location; otherwise, the independent device is installed at the designated location.

8. A distribution network voltage-type traveling wave ranging switch and independent device deployment system, characterized in that, The system includes: Data unit: used to preset the point layout rules and the maximum equivalent number of branches N, and obtain the topology map of the target area, where N is an integer greater than or equal to 1; Starting point unit: used to determine the location of the first traveling wave ranging device based on the topology map; Initial unit: used to obtain a number of first nodes based on the layout locations and the topology map, calculate the first equivalent branch number M for each first node based on the layout locations, obtain a number of second nodes based on the first equivalent branch number M and the maximum equivalent branch number N, and obtain the initial position based on the maximum value of the second nodes and the first equivalent branch number M, where M is a positive number; Analysis unit: Used to determine whether the initial position satisfies the placement rule. If it does, the placement position is updated to the initial position, and the process returns to the initial unit until the placement position covers the target area, and S5 is executed. If it does not satisfy the rule, the initial position is adjusted to obtain the adjusted position, the initial position is updated to the adjusted position, and the process returns to the analysis unit. Deployment unit: used to deploy the traveling wave ranging device based on the deployment location; In the initial unit, the first equivalent branch number M is obtained in the following way: Based on the topology map, the node region from the point location to each first node is obtained, the node lines of the node region are divided, and several topology structures are obtained. Each topology structure corresponds to a different equivalent branch conversion method. Obtain the line length of each topology, and based on the line length and the equivalent branch conversion method, obtain the second equivalent branch number of each topology; The first equivalent branch number M for each first node is obtained by superimposing the second equivalent branch number. The specific steps for obtaining the initial position in the initial unit further include: S301. Based on the downlink direction of the distribution network line, obtain the second node adjacent to the initial position to obtain the node position; S302. Based on the node position, the placement position, and the method of obtaining the first equivalent branch number M, calculate the third equivalent branch number M1 of the node position; S303. If the maximum value of the first equivalent branch number M is less than the maximum equivalent branch number N, and the third equivalent branch number M1 is greater than the maximum equivalent branch number N, then the initial position is determined as the placement position; if the conditions are not met, then return to S301, update the initial position to the node position, and update the maximum value of the first equivalent branch number M to the third equivalent branch number M1.

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