CN111614164B

CN111614164B - Low-voltage distribution station topology identification method

Info

Publication number: CN111614164B
Application number: CN202010487237.2A
Authority: CN
Inventors: 范伟; 王东杰; 刘卫强; 孙佳伟; 马天祥; 刘滨滨; 沈晓娇; 李江峰; 王强; 刘海涛; 王鹏; 李春海; 翟志国; 王琳; 孟楠; 尹卫卫; 李飞
Original assignee: Shijiazhuang Kelin Electric Co Ltd
Current assignee: Shijiazhuang Kelin Electric Co Ltd
Priority date: 2020-06-02
Filing date: 2020-06-02
Publication date: 2021-08-13
Anticipated expiration: 2040-06-02
Also published as: CN111614164A

Abstract

A topology identification method for a low-voltage distribution area belongs to the field of distribution automation in an electric power system, and particularly relates to a method for automatically identifying a topology structure of the low-voltage distribution area. The method is realized based on a TTU, a wave trap device and a branch monitoring unit which are arranged at the inlet wire end of a distribution box; the branch monitoring unit comprises an uplink module and a downlink module which are respectively arranged at two ends of the wave trap; the uplink module exchanges a topology identification command with a higher distribution box, and the downlink module exchanges a topology identification command with a lower distribution box; the topology identification command is transmitted through a power line by adopting a frequency band blocked by a wave trap; the TTU sends out a topology identification command, each node forwards the command and adds self information in the command, and the TTU collects the returned topology identification command and completes topology identification according to the identity information in the command. By adopting the invention, the communication mechanism of the communication line with controllable direction and the command forwarding is adopted, and the logic is clear; the topology identification command is limited to be transmitted between the two distribution boxes, and the control is simple; in the summarized information, the position of the ID indicates the upper-level and lower-level relation of the topology, and the TTU can easily realize the generation of the topology.

Description

Low-voltage distribution station topology identification method

Technical Field

The invention belongs to the field of distribution automation in a power system, and particularly relates to a method for automatically identifying a topological structure of a low-voltage transformer area.

Background

In a power distribution network, the premise of realizing the intelligent monitoring of distribution of a distribution area is that the topological structure of the distribution area is known, but in the daily distribution operation and maintenance management work, the situation that the connection relation of users is not clear often exists, particularly in a newly-built distribution area, part of topology cannot be directly obtained at all, manual touch check is needed, and the workload is huge; when the actual topology changes, the changes are manually recorded and the topology data is updated, or special organizations manually perform on-site patrolling to correct the errors. The manual general survey, because the low voltage distribution network line distribution is complicated, and cable pit or overhead line lay in parallel, patrol and examine not only inefficiency, with high costs, can't acquire low-voltage platform district topology information moreover accurately.

The use of passive optical Ethernet (EPON) in the power grid provides many possible solutions for automatic identification of the topology of the distribution area, but no fiber optic communication network is yet popular in the current distribution networks.

In order to automatically identify the topology of the low-voltage distribution area, patent application publication No. CN108270678A discloses a method and a system for determining the topology of a low-voltage power line network, where pulse current needs to be injected into a power line and topology identification is realized by tracking the pulse current. The patent application publication No. CN107483082A discloses a low-voltage distribution area topology automatic identification method and system based on a power frequency carrier communication technology, the method is characterized in that a concentrator is transformed to have a power frequency communication function, devices with the power frequency communication function are added to a user side, and the concentrator and the devices automatically identify distribution area topology in a power frequency communication mode. However, the problem of common high-voltage crosstalk in a transformer area can be caused due to the fact that the power frequency communication frequency is relatively low.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a method for constructing a direction-controllable communication mechanism based on the existing power line, and completing the topology identification of a low-voltage distribution network area by using a topology generation protocol.

In order to achieve the purpose, the invention adopts the technical scheme that: a topology identification method for a low-voltage distribution substation area is realized based on a TTU, a wave trap and a branch monitoring unit, wherein the wave trap is installed at a wire inlet end in a distribution box;

the wave trap prevents the transmission of signals of a specific frequency band;

the branch monitoring unit has a unique ID of the whole network and comprises an uplink module and a downlink module which are respectively arranged at two ends of the wave trap; the uplink module exchanges a topology identification command with a higher distribution box, and the downlink module exchanges a topology identification command with a lower distribution box;

the topology identification command is transmitted through a power line by adopting a frequency band blocked by a wave trap;

the topology identification method comprises the following steps:

step A, TTU is used as a root node, a topology identification command is generated periodically and sent through a downlink module in the root node distribution box;

b, after receiving the topology identification command through the uplink module, the branch monitoring unit sends the topology identification command through the downlink module;

step C, after receiving the topology identification command through the uplink module, the branch monitoring unit waits for a certain time, and if the downlink module does not receive the topology identification command, the branch monitoring unit sends the topology identification command through the uplink module; if the branch monitoring unit receives the topology identification command through the downlink module, the branch monitoring unit sends the topology identification command through the uplink module;

step D, TTU, after receiving all the topology identification commands, generating the topology of the whole platform area according to the information in the topology identification commands;

the information in the topology identification command includes the ID of each branch monitoring unit, which is added to the topology identification command in step B or step C.

The power carrier communication is widely applied to the power distribution network, and the invention avoids the conventional communication frequency band and can ensure the existing communication function.

The wave trap is the key to construct a controllable directional communication mechanism. By providing a wave trap in each distribution box, it is ensured that communication only takes place between two distribution boxes. The topology identification command is forwarded through the branch monitoring units in the distribution boxes, and the command can be sent to all distribution boxes in the whole network and finally collected to the TTU. The aggregated topology identification commands include the IDs of the branch monitoring units, and the nodes and routes that each topology identification command passes through can be seen. The TTU analyzes the information in the summarized command to obtain the topology of the whole network.

Has the advantages that: by adopting the invention, instantaneous pulse current does not need to be injected into a power grid, the function of the existing system is not influenced, only independent equipment is added at the wire inlet end of the distribution box, and the function is simple to realize. The logic is clear by adopting a communication line with controllable direction and a communication mechanism for forwarding commands; the topology identification command is limited to be transmitted between the two distribution boxes, and the control is simple; in the summarized information, the position of the ID indicates the upper-level and lower-level relation of the topology, and the TTU can easily realize the generation of the topology.

Drawings

Figure 1 is a schematic view of the installation of the apparatus,

figure 2 is a schematic view of a mesa configuration,

FIG. 3 is the identified topology.

Detailed Description

In the distribution box, the equipment and connections related to the invention are shown in fig. 1: a wave trap is installed at the incoming line end in the distribution box, and an uplink module and a downlink module in the branch monitoring unit are respectively installed at two ends of the wave trap. The branch monitoring unit also comprises a central processing unit and peripheral equipment, and is used for finishing the detection of a received command, the generation of a topology command and the control and transmission. The branch monitoring unit has a network-wide unique ID. The ID of the branch monitoring unit represents the local distribution box, and may also be the ID of the distribution box. For simplicity of description, the ID below the specification represents the branch monitoring unit in the electrical box.

The outgoing line of the higher distribution box is the incoming line of the lower distribution box.

The topology identification command is transmitted through the power line by adopting the frequency band blocked by the wave trap, so that the topology identification command is only transmitted between the two wave traps at the upper level and the lower level. In the embodiment, the frequency band for preventing the trap from transmitting signals is 400-500KHz, and the topology identification command is transmitted in the frequency band through the power line.

Generally, the speed of a meter reading type chip is low, and the carrier wave is in a KHz level. In the United states, the Federal communications Commission FCC stipulates that the bandwidth of a power line is 100-450 kHZ; in Europe, EN50065-1 of the European Electrical standards Committee specifies a power carrier band of 3 to 148.5 kHZ. The special chip for domestic carrier communication meets European standards of 2 families, and is respectively three options of 120KHz and Submicron 57.6KHz/76.8KHz/115.2KHz in the Fuxing-Xiao Cheng.

The wave trap adopted in the invention can not influence the normal meter reading communication transmission. In practical application, the transmission frequency band blocked by the wave trap can be planned according to practical situations.

The uplink module exchanges a topology identification command with a higher-level distribution box, and the downlink module exchanges a topology identification command with a lower-level distribution box.

Example 1, see fig. 2, with the rightmost branch taken as an example.

Step A, TTU is used as a root node, a topology identification command is generated periodically and sent through a downlink module in the root node distribution box; the ID of the branch monitoring unit in the root node distribution box is ID0, and the topology identification command is added with ID 0.

And step B, after the branch monitoring unit of the first-stage distribution box ID3 receives the topology identification command through the uplink module, adding the self ID, namely ID3 into the topology identification command, and sending the topology identification command through the downlink module, wherein the topology identification command comprises ID0 and ID 3.

The same procedure is completed by the second-level distribution box ID8, and the topology identification command comprises ID0, ID3 and ID 8.

After the upstream module of the final distribution box ID12 receives the topology identification command, it may not send the topology identification command downward because there is no distribution box below, or may operate according to a general situation and issue the command as well.

At this time, the topology identification commands include ID0, ID3, ID8, and ID 12.

After the branch monitoring unit of step C, ID12 receives the topology identification command through the uplink module, there is no command to upload because there is no lower distribution box. And after waiting for a certain time, sending a topology identification command through the uplink module.

The ID8 branch monitoring unit receives the topology identification command sent by the ID12 through the downlink module and sends the topology identification command through the uplink module.

The ID3 branch monitoring unit receives the topology identification command sent by the ID8 through the downlink module and sends the topology identification command through the uplink module.

The ID0 finally receives the topology identification command uploaded by the branch, and the topology identification command includes ID0, ID3, ID8 and ID 12.

Root node ID0 receives back the same number of topology identification commands as the end switchboards.

Step D, TTU generates the topology of the whole distribution area according to the information in the topology identification command after receiving all the topology identification commands, as shown in fig. 3.

In this embodiment, the ID of each branch monitoring unit in the topology identification command is added when the topology identification command is issued, and each branch monitoring unit does not modify the topology identification command when forwarding the uplink topology identification command.

In step C, the branch monitoring unit in the final distribution box waits for a period of time, does not receive the uploaded command, and sends the topology identification command through the uplink module.

If the waiting time of all the branch monitoring units is the same, nodes of lower-level switchgears, such as the switchgears ID3 and ID8, can also send topology identification commands through the uplink module under the condition that the uploading commands are not received, and when the uploading commands are received, the topology identification commands are uploaded again. In this case, the TTU receives a large number of invalid topology identification commands, and although an algorithm may be used to exclude the invalid commands, the TTU is burdened.

The invention solves the problem that the distribution box closer to the root node has the shortest waiting time and the distribution box at the last stage has the shortest waiting time.

The solution is as follows: setting a waiting time T in the topology identification command generated in the step A, wherein in the embodiment, T =3 seconds; and step B, resetting the waiting time T in the received topology identification command into the topology identification command after resetting, and sending the reset value to be 60% T through the downlink module.

In this embodiment, the waiting time for ID3 is 3 seconds, the waiting time for ID8 is 1.8 seconds, and the waiting time for ID12 is 1.08 seconds.

The ID12 waits for 1.08 seconds and does not receive the uploaded topology identification command, and then the topology identification command is sent through the uplink module; the ID8 receives the topology identification command uploaded by the ID12 within 1.8 seconds of waiting time, and the topology identification command is sent by the uplink module and is only sent once; ID3 performs the same operation.

Example 2, see fig. 2, take the leftmost branch as an example.

Step A, TTU is used as a root node, a topology identification command is generated periodically and sent through a downlink module in the root node distribution box; the latency T =3 seconds in the topology identification command.

And step B, after the branch monitoring unit of the first-stage distribution box ID1 receives the topology identification command through the uplink module, changing the waiting time in the topology identification command to 1.8 seconds, and sending the topology identification command through the downlink module.

After the branch monitoring unit of step C, ID4 receives the topology identification command through the uplink module, there is no command to upload because there is no lower distribution box. And after waiting for 1.8 seconds, adding the ID of the user into the topology identification command, and sending the topology identification command through the uplink module, wherein the topology identification command comprises the ID 4.

The ID1 branch monitoring unit receives the topology identification command sent by the ID4 through the downlink module, adds the ID of the branch monitoring unit into the topology identification command, and sends the topology identification command through the uplink module, wherein the topology identification command comprises the ID4 and the ID 1.

The ID0 finally receives the topology identification command uploaded by the branch, and the topology identification command includes ID4 and ID 1. In order to be the same as the information obtained in embodiment 1, the ID0 adds its own ID, and the final topology identification command includes ID4, ID1, and ID 0.

In this embodiment, the ID of each branch monitoring unit in the topology identification command is added when the topology identification command is uploaded, and the branch monitoring units do not modify the topology identification command when forwarding the downlink topology identification command.

Example 3, see fig. 2, with the middle branch taken as an example.

Assume that ID10 is a newly added distribution box and has not been updated into the topology. In this case, the TTU may initiate topology identification to incorporate the newly added node into the topology of the station.

The invention provides a method, which can start a topology identification process by a branch monitoring unit in a newly-added distribution box and bring the topology identification process into a distribution area topology.

And sending a topology identification command through the downlink module to start a topology identification process.

After the ID10 sends the topology identification command through the downlink module, the topology identification command is sent through the uplink module after waiting for a period of time due to the fact that no lower distribution box exists, and the topology identification command comprises the ID 10.

The ID6 branch monitoring unit receives the topology identification command sent by the ID10 through the downlink module, adds the ID of the branch monitoring unit into the topology identification command, and sends the topology identification command through the uplink module, wherein the topology identification command comprises the ID10 and the ID 6.

The ID2 branch monitoring unit receives the topology identification command sent by the ID6 through the downlink module, adds the ID of the branch monitoring unit into the topology identification command, and sends the topology identification command through the uplink module, wherein the topology identification command comprises the ID10, the ID6 and the ID 2.

The ID0 finally receives the topology identification command uploaded by the branch, and the topology identification command includes ID10, ID6 and ID 2.

And sending a topology identification command through the uplink module to start a topology identification process.

The ID10 sends a topology identification command through the upstream module, the topology identification command including the ID 10.

In the above embodiment, when the branch monitoring unit receives the topology identification command through the uplink module, or the branch monitoring unit receives the topology identification command through the downlink module, the branch monitoring unit may further reply an acknowledgement to the sending end. In this case, if the sender does not receive the acknowledgement, the topology identification command is retransmitted.

Example 4, topology identification.

The present embodiment identifies the topology by the topology identification command received in embodiment 1.

The topology identification commands received by the TTU are as follows:

1、ID0 ID1 ID4

2、ID0 ID1 ID5 ID9

3、ID0 ID2 ID6 ID10

4、ID0 ID2 ID6 ID11

5、ID0 ID3 ID7

6、ID0 ID3 ID8 ID12

and D-1, traversing the received topology identification commands, and repeating 13 ID tools.

And D-2, establishing a 13 x 13 two-dimensional matrix M, wherein the first row and the first column of the matrix represent the ID0 of the root node, and all variables in the matrix are set to be 0.

The representation positions of other IDs in the matrix can be set arbitrarily, for example, arranged according to the size of the ID. In this embodiment, for simple processing, the positions of the IDs of the branch monitoring units in the other distribution boxes in the matrix are arranged in the discovery order.

Assuming that topology identification command 1 is processed first, the matrix is as follows:

	ID0	ID1	ID4
														ID0	0	0	0	0	0	0	0	0	0	0	0	0	0
ID1	0	0	0	0	0	0	0	0	0	0	0	0	0
														ID4	0	0	0	0	0	0	0	0	0	0	0	0	0
	0	0	0	0	0	0	0	0	0	0	0	0	0
															0	0	0	0	0	0	0	0	0	0	0	0	0
	0	0	0	0	0	0	0	0	0	0	0	0	0
															0	0	0	0	0	0	0	0	0	0	0	0	0
	0	0	0	0	0	0	0	0	0	0	0	0	0
															0	0	0	0	0	0	0	0	0	0	0	0	0
	0	0	0	0	0	0	0	0	0	0	0	0	0
															0	0	0	0	0	0	0	0	0	0	0	0	0
	0	0	0	0	0	0	0	0	0	0	0	0	0
															0	0	0	0	0	0	0	0	0	0	0	0	0

the relationship between the matrix and each ID established at last is as follows:

	ID0	ID1	ID4	ID5	ID9	ID2	ID6	ID10	ID11	ID3	ID7	ID8	ID12
														ID0	0	0	0	0	0	0	0	0	0	0	0	0	0
ID1	0	0	0	0	0	0	0	0	0	0	0	0	0
														ID4	0	0	0	0	0	0	0	0	0	0	0	0	0
ID5	0	0	0	0	0	0	0	0	0	0	0	0	0
														ID9	0	0	0	0	0	0	0	0	0	0	0	0	0
ID2	0	0	0	0	0	0	0	0	0	0	0	0	0
														ID6	0	0	0	0	0	0	0	0	0	0	0	0	0
ID10	0	0	0	0	0	0	0	0	0	0	0	0	0
														ID11	0	0	0	0	0	0	0	0	0	0	0	0	0
ID3	0	0	0	0	0	0	0	0	0	0	0	0	0
														ID7	0	0	0	0	0	0	0	0	0	0	0	0	0
ID8	0	0	0	0	0	0	0	0	0	0	0	0	0
														ID12	0	0	0	0	0	0	0	0	0	0	0	0	0

and D-3, traversing the received topology identification command, and if IDi and IDj appear in the same instruction and are arranged adjacently, IDi appears in the p row and p column in the matrix, and IDj appears in the q row and q column in the matrix, setting the elements M (p, q) and M (q, p) in the matrix to be 1.

Take topology identification command 1, ID0 ID1 ID4 as an example.

The position of ID1 in the matrix is the second row and the second column, ID0 appears in the instruction at the same time as ID1 and is arranged adjacent to it, M (2, 0) =1, M (0, 2) = 1.

The position of the ID4 in the matrix is the third row and the third column, the ID1 is present in the instruction at the same time as the ID4 and arranged adjacent to each other, M (3, 2) =1, and M (2, 3) = 1.

After traversing all the topology identification commands, the generated matrix is as follows:

	ID0	ID1	ID4	ID5	ID9	ID2	ID6	ID10	ID11	ID3	ID7	ID8	ID12
														ID0	0	1	0	0	0	1	0	0	0	1	0	0	0
ID1	1	0	1	1	0	0	0	0	0	0	0	0	0
														ID4	0	1	0	0	0	0	0	0	0	0	0	0	0
ID5	0	1	0	0	1	0	0	0	0	0	0	0	0
														ID9	0	0	0	1	0	0	0	0	0	0	0	0	0
ID2	1	0	0	0	0	0	1	0	0	0	0	0	0
														ID6	0	0	0	0	0	1	0	1	1	0	0	0	0
ID10	0	0	0	0	0	0	1	0	0	0	0	0	0
														ID11	0	0	0	0	0	0	1	0	0	0	0	0	0
ID3	1	0	0	0	0	0	0	0	0	0	1	1	0
														ID7	0	0	0	0	0	0	0	0	0	1	0	0	0
ID8	0	0	0	0	0	0	0	0	0	1	0	0	1
														ID12	0	0	0	0	0	0	0	0	0	0	0	1	0

and D-4, traversing the first column of the matrix, wherein if the matrix element M (x, 1) =1, the ID represented by the x-th column in the matrix is the lower node of the root node.

In this embodiment, M (2, 1) =1, M (6, 1) =1, M (10, 1) =1, and the 2 nd, 6 th, and 10 th columns in the matrix represent ID1, ID2, and ID3, respectively, and these three nodes are root node subordinate nodes.

And D-5, traversing other columns of the matrix, wherein if the matrix element M (y, z) =1, the ID represented by the y column in the matrix is the upper node or the lower node of the node represented by the z column in the matrix.

In this embodiment, starting from the second column:

in column 2, M (1, 2) =1, M (3, 2) =1, and M (4, 2) =1, and columns 1, 3, and 4 in the matrix represent ID0, ID4, and ID5, respectively.

The 2 nd column in the matrix represents that the node is ID1, ID0 is the upper node thereof, and ID4 and ID5 are the lower nodes of ID 1.

In column 3, M (2, 3) =1, and column 2 in the matrix represents ID 1.

Column 3 in the matrix represents the node as ID4 and ID1 as its superordinate node. ID4 has no subordinate node.

The same is done for the other columns in the matrix.

The results are as follows:

lower node of ID 0: ID1, ID2, ID 3.

Upper or lower node of ID 1: ID0, ID4, ID 5.

Upper or lower node of ID 4: ID 1.

Upper or lower node of ID 5: ID1, ID 9.

Upper or lower node of ID 9: ID 5.

Upper or lower node of ID 2: ID0, ID 6.

Upper or lower node of ID 6: ID2, ID10, ID 11.

Upper or lower node of ID 10: ID 6.

Upper or lower node of ID 11: ID 6.

Upper or lower node of ID 3: ID0, ID 7.

Upper or lower node of ID 7: ID 3.

Upper or lower node of ID 8: ID3, ID 12.

Upper or lower node of ID 12: ID 8.

And (3) according to the lower nodes of the root node ID0, descending step by step, and removing repeated upper nodes to obtain the topology of the whole platform area, as shown in figure 3.

The above processing procedure may be performed in accordance with the rows of the matrix.

Claims

1. A topology identification method for a low-voltage distribution substation is characterized by being realized based on a TTU, a wave trap and a branch monitoring unit, wherein the wave trap is installed at a wire inlet end in a distribution box;

the topology identification method comprises the following steps:

the information in the topology identification command includes the ID of each branch monitoring unit, and the information is added to the topology identification command in step B or step C;

setting a waiting time T in the topology identification command generated in the step A, resetting the waiting time T in the received topology identification command in the step B after resetting, and sending the reset value to be 60% T through a downlink module; in step C, the waiting time is the waiting time set in the received topology identification command.

2. The topology identification method according to claim 1, wherein the frequency band of the wave trap for preventing signal transmission is 400-500 KHz.

3. The topology identification method of claim 1,

in the step B, if the distribution box where the branch monitoring unit is located is the final-stage distribution box, the topology identification command is not sent through the downlink module.

4. The topology identification method of claim 1,

the topology identification method further comprises the following steps:

and E, the branch monitoring unit at any position sends a topology identification command through the downlink module or the uplink module.

5. The topology identification method according to claim 1, wherein the branch monitoring unit replies an acknowledgement to the sender after receiving the topology identification command.

6. The topology identification method according to claim 1, wherein in step D, the step of generating the topology comprises:

d-1, traversing the received topology identification command to obtain the number m of unrepeated IDs;

d-2, establishing an M x M two-dimensional matrix M, wherein the first row and the first column of the matrix represent the ID of a root node, and all variables in the matrix are set to be 0;

d-3, traversing the received topology identification command, and if IDi and IDj appear in the same instruction and are arranged adjacently, IDi appears in the p row and the p column in the matrix, and IDj appears in the q row and the q column in the matrix, setting the elements M (p, q) and M (q, p) in the matrix to be 1;

d-4, traversing the first column of the matrix, wherein if the matrix element M (x, 1) =1, the ID represented by the x-th column in the matrix is a lower node of the root node;

7. The topology identification method of claim 6, wherein in step D-2, the IDs of the branch monitoring units in the other cabinets are arranged in the order of discovery.

8. The topology identification method according to claim 6, wherein in steps D-3 to D-5, traversal is performed by rows of a matrix.