CN114157033A

CN114157033A - Distributed power distribution network topology identification method and system based on measurement data

Info

Publication number: CN114157033A
Application number: CN202111482436.5A
Authority: CN
Inventors: 崔健; 胡小晔; 陈朝朝; 崔晓红; 孟祥泉
Original assignee: Qingdao Eastsoft Communication Technology Co Ltd
Current assignee: Qingdao Eastsoft Communication Technology Co Ltd
Priority date: 2021-12-07
Filing date: 2021-12-07
Publication date: 2022-03-08

Abstract

The invention belongs to the technical field of power communication, and discloses a distributed distribution network topology identification method and system based on measurement data, which comprises the following steps: s1, powering on the node module and adding the node module into the network; simultaneously, monitoring messages sent by other nodes, and calculating the RSSI value of the neighbor node; s2, the node module starts a topology identification process according to the RTC clock periodically, sends a voltage data acquisition command to the intelligent ammeter, receives voltage data returned by the ammeter, and then sends one-hop local broadcast for other nodes to receive and process; s3, the node module determines a father node identified this time by combining the RSSI value and the voltage data of the neighbor node; s4, the node module uploads the father node obtained by identification to the routing module; and S5, the routing module draws a complete network topology map according to the father node information uploaded by each node module. The invention does not need to add equipment, improves the identification efficiency through distributed identification and reduces the system operation amount.

Description

Distributed power distribution network topology identification method and system based on measurement data

Technical Field

The invention relates to the technical field of power communication, in particular to a distributed power distribution network topology identification method and system based on measurement data.

Background

The topological structure of the power distribution network is characterized in that elements such as a concentrator, a collector and a smart meter are connected with a power grid through a switch device such as a breaker, the elements are abstracted into nodes irrelevant to the types of the elements, power lines connecting the nodes are abstracted into lines, and then the relationship among the nodes is represented in the form of a topological graph.

The topology identification of the low-voltage distribution network is to distinguish the superior-subordinate relation and the subordinate relation of each node in a power supply line in a distribution area, visualize the low-voltage distribution area, improve the efficiency of on-site fault troubleshooting and solve the operation and maintenance pain which troubles power companies for a long time. At present, topology identification mainly has two technical routes: one is that a sensing device is installed at a branch node of a low-voltage power supply network topology through power line carrier communication or injection of a special signal into a circuit, so as to identify the network topology; the other method is a topology identification and reduction method based on data driving, and the network topology identification is realized by analyzing the measured data of the intelligent electric meter and mining the internal relation between the electric quantity data and the topology. The first mode needs to add a transceiver in the power grid, changes the existing network environment and has higher cost. The second method mainly relies on centralized identification realized by a routing module at present, and has the disadvantages of complex algorithm, large computation amount and excessive occupied resources.

Disclosure of Invention

In order to meet the actual requirements in the technical field of power communication, the invention overcomes the defects in the prior art and solves the technical problems that: the distributed distribution network topology identification method and system based on the measured data are provided, so that the defects of large computation amount and excessive resource occupation of centralized identification are overcome.

In order to solve the technical problems, the invention adopts the technical scheme that: a distributed distribution network topology identification method based on measurement data is disclosed, wherein the distribution network comprises a distribution transformer, a concentrator, a routing module arranged on the concentrator, an intelligent electric meter and a node module arranged on the intelligent electric meter; the node module and the routing module realize data transceiving through HPLC communication, and the topology identification method comprises the following steps:

s1, the node module is powered on and added into the network of the routing module, and meanwhile, the node module starts to monitor messages sent by other nodes and calculates the RSSI value of the neighbor node;

s2, the node module sends a voltage data acquisition command to the intelligent ammeter periodically according to the RTC clock, and the ammeter returns voltage data to the node module after receiving the command; after receiving the voltage data, the node module sends one-hop local broadcast to the power line for receiving and processing by the neighbor node;

s3, the node module determines a father node identified this time by combining the RSSI value and the voltage data of the neighbor node;

s4, after multiple identification, the node module takes the father node with the most statistical identification times as the father node of the node module and uploads the father node to the routing module;

and S5, the routing module draws a complete network topology map according to the father node information uploaded by each node module.

The step S3 specifically includes the following steps:

s301, sequencing neighbor nodes according to the RSSI values, and taking the first N maximum nodes as father nodes to be selected;

s302, removing nodes which do not meet the conditions in the father nodes to be selected;

and S303, taking the node with the maximum RSSI value from the rest father nodes to be selected as the father node identified at this time.

In step S302, the nodes that do not meet the condition include a node whose node voltage is lower than the voltage of the node, a node whose RSSI value is greater than the first threshold, and a node that does not have access to the network or has an RSSI value of zero.

The first threshold value is an RSSI value between nodes in the same meter box obtained through actual test.

In step S301, when the number of nodes in the distribution room is less than N, all the nodes are taken as parent nodes to be selected.

In step S303, if the RSSI values of the nodes are the maximum and the same, the node with the maximum voltage is taken as the parent node identified this time.

In step S303, if there is no eligible parent node, it is determined whether the RSSI of the routing module received by the node module is greater than the second threshold, and if so, the routing module is used as the parent node identified this time.

The second threshold is the RSSI value between the node closest to the routing module and the routing module obtained by actual testing.

In step S2, the node module implements the above steps S1 to S3 by means of a state machine, and the state machine has 4 states: TOPO _ IDLE, TOPO _ START, TOPO _ PRE, TOPO _ ING, wherein:

TOPO _ IDLE state: when the intelligent electric meter is in a waiting state and enters an NTB timed interrupt comparison interrupt processing function, a voltage data acquisition command is sent to the intelligent electric meter through a serial port and is sent out, and meanwhile, the program flow enters a TOPO _ START state;

TOPO _ START state: sequencing the RSSI of the neighbor nodes, and entering a TOPO _ PRE state after the sequencing is finished;

TOPO _ PRE state: collecting voltage data broadcasted by a neighbor node, and entering a TOPO _ ING state after the collection is finished;

TOPO _ ING state: and (5) carrying out father node identification, returning after the identification is finished, and keeping in a waiting state.

In addition, the invention also provides a distributed distribution network topology identification system based on the measured data, which is used for the distributed distribution network topology identification method based on the measured data.

The working principle of the invention is described as follows:

the topology identification of the power distribution network is realized mainly through a father node identification algorithm of the node modules, wherein the routing module mainly counts identification results of all the node modules and displays the identification results. The father node identification algorithm is realized based on the effective value of the 220V alternating voltage measured by the intelligent electric meter on the line of the low-voltage distribution network and the received signal strength of the surrounding neighbor nodes. Firstly, all nodes in a transformer area collect the voltage measurement value of an ammeter at the same moment. Under the influence of load current on a line, the node farther away from the transformer is subjected to voltage drop increase of the line, and the measured effective value of the alternating current 220V voltage is gradually reduced, so that the distance between each node and the transformer can be judged. Each node sends out the collected electric meter voltage data through local one-hop broadcast communication, and then other nodes within a certain distance range around can receive the communication message. Therefore, each node can acquire voltage data of all surrounding neighbor nodes and judge the distance between other nodes and the transformer compared with the node. Because the voltage data on the distribution line measured by the ammeter is adopted, a signal receiving and transmitting device does not need to be additionally arranged, and the realization is more convenient. However, the voltage values of other nodes on different branches may be the same as the voltage value of the parent node on the branch, so that the parent node cannot be accurately judged only by the voltage data of the electric meter. The RSSI value of other neighbor nodes (Received Signal Strength Indicator) is calculated by using the node module, and the farther the node module is away from the RSSI value, the weaker the RSSI value is, so that the distance between other nodes and the node module can be judged. Since the distance between the node on different branches and the adjacent node on the same branch is relatively long, the received signal strength is also relatively weak, so that different branches are distinguished. Therefore, different branches are distinguished through the received signal strength, and the front-back relation between the nodes is judged through the voltage of the electric meter, so that the father node can be accurately judged. And the routing module counts father node information of each node, and if a certain node is not the father node of any node, the node is a terminal leaf node. Topology learning begins at the end leaf node, and each line branch can be traversed in sequence through the superior-inferior relation of each node. If the two branches are finally converged to the same node or routing module, two branches are automatically formed. Therefore, a complete network topology graph can be drawn.

In conclusion, compared with the prior art, the invention has the following beneficial effects:

1. the distributed topology identification method provided by the invention has the advantages that the measurement data of the electric meter and the received signal strength among the nodes are acquired by the nodes, the father node of the node is automatically calculated, the identification result is reported to the routing module for statistics, the defects of large centralized identification computation amount and excessive resource occupation are avoided, the identification efficiency is improved through distributed identification, and the computation amount of the system is reduced.

2. The invention does not need to distinguish the topological branch of each node in advance, the routing module can automatically distinguish each branch path according to the father node reported by each node, thereby obtaining the topological graph of the whole platform area, and the algorithm is simple and effective, thereby having stronger practicability.

3. The invention does not need to add equipment, does not change the power grid environment, relies on power line communication for identification and has lower cost.

Drawings

Fig. 1 is a block diagram of a power distribution network according to an embodiment of the present invention;

fig. 2 is a schematic flowchart of a distributed distribution network topology identification method based on measurement data according to an embodiment of the present invention;

fig. 3 is a flowchart of the operation of the node module in the embodiment of the present invention.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention; all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The embodiment of the invention provides a distributed distribution network topology identification method based on measurement data, and as shown in fig. 1, the distribution network comprises a distribution transformer, a concentrator, a routing module installed on the concentrator, an intelligent electric meter and a node module installed on the intelligent electric meter; and the node module and the routing module realize data receiving and transmitting through HPLC communication. The topology identification method of the embodiment is realized by the effective value of alternating 220V voltage measured by the intelligent electric meter on the line of the low-voltage distribution network and the received signal strength of the surrounding neighbor nodes.

Specifically, according to the topology identification method provided by the embodiment of the invention, the voltage measurement values of the electric meters at the same moment are collected through all the node modules in the distribution area. Under the influence of load current on a line, the node farther away from the transformer is subjected to voltage drop increase of the line, and the measured effective value of the alternating current 220V voltage is gradually reduced, so that the distance between each node and the transformer can be judged. And each node module sends the collected voltage data of the electric meter out through local one-hop broadcast communication, and then other nodes within a certain distance range around the node module can receive the communication message. Therefore, each node can acquire voltage data of all surrounding neighbor nodes and judge the distance between other nodes and the transformer compared with the node. Because the voltage data on the distribution line measured by the ammeter is adopted, a signal receiving and transmitting device does not need to be additionally arranged, and the realization is more convenient. However, the voltage values of other nodes on different branches may be the same as the voltage value of the parent node on the branch, so that the parent node cannot be accurately judged only by the voltage data of the electric meter. Therefore, the node module is used for calculating the received signal strength of other neighbor nodes, and the farther the node is, the weaker the received signal strength is, so that the distance between other nodes and the node can be judged. Since the distance between the node on different branches and the adjacent node on the same branch is relatively long, the received signal strength is also relatively weak, so that different branches are distinguished. Therefore, different branches are distinguished through the received signal strength, and the front-back relation between the nodes is judged through the voltage of the electric meter, so that the father node can be accurately judged.

In addition, in the topology identification method of this embodiment, the routing module counts the parent node information of each node module, and if a certain node module is not a parent node of any node, the node is a terminal leaf node. Topology learning begins at the end leaf node, and each line branch can be traversed in sequence through the superior-inferior relation of each node. If the two branches are finally converged to the same node or routing module, two branches are automatically formed. Accordingly, a complete network topology map as shown in fig. 1 can be drawn.

As shown in fig. 2, in this embodiment, the topology identification method includes the following steps:

s1, the node module is powered on and added into the network of the routing module, and receives the timing message sent by the routing module in a broadcasting mode, and the node module updates a local RTC (real Time clock) real-Time clock after receiving the timing message, wherein the clock precision is second; meanwhile, after the node module is powered on, the node module starts to continuously monitor messages sent by other nodes, and calculates the RSSI (received Signal Strength indicator) value of the neighbor node.

Further, in this embodiment, after being powered on, the node module continuously monitors messages sent by other nodes, calculates the RSSI received signal strength of the neighbor node, and calculates an average value in a period of time as the RSSI value of the neighbor node.

S2, the node module periodically updates an NTB timed interrupt comparison value according to the RTC clock, and enters an interrupt processing function when the NTB clock reaches the NTB timed interrupt comparison value; a topology identification flow starting mark is set in the interrupt processing function, a voltage data acquisition command is sent to the intelligent ammeter through a serial port, and the ammeter returns voltage data to the node module after receiving the command; and after receiving the voltage data, the node module sends one-hop local broadcast to the power line for other nodes to receive and process.

Each node module and the routing module maintain a synchronous NTB (network Time base) network reference clock, and the precision of the clock can reach 40 ns. And the node module updates the NTB timing interrupt comparison value once every 2 minutes according to the RTC clock, and enters an interrupt processing function when the NTB clock reaches the value. And setting a topology identification process starting mark in the interrupt processing function, and sending a voltage data acquisition command to the intelligent electric meter through a serial port. And the electric meter returns voltage data to the node module after receiving the command. And after receiving the voltage data, the node waits for a random delay, and then sends the voltage data to a power line for one-hop local broadcast for other nodes to receive and process.

And S3, the node module determines the father node identified at this time by combining the RSSI value and the voltage data of the neighbor node.

Specifically, in this embodiment, after the topology identification process of the node module is started, the RSSI values of the neighbor nodes are sequenced, the top N nodes are taken as parent nodes to be selected, and if the number of nodes in the local station area is less than N, all the nodes are taken as parent nodes to be selected, where in this embodiment, the value of N is 100. And then waiting for 10 seconds to finish collecting voltage data of the neighbor nodes, and then removing the nodes which do not meet the conditions, wherein the removed nodes comprise:

(1) a node having a node voltage lower than the present node voltage;

(2) and the node with the RSSI value larger than the first threshold value RSSI _1 is considered as a node of the same meter box. Wherein the first threshold value rssi _1 is the received signal strength between the nodes in the same meter box obtained by actual test;

(3) there are no nodes that are networked or have an RSSI value of 0.

And then taking the node with the maximum RSSI value from the rest nodes as a father node identified at this time. And if the RSSI values of a plurality of nodes are the maximum and the same, taking the node with the maximum voltage as the father node identified at this time. If no father node meeting the conditions exists, whether the RSSI of the routing module received by the node is greater than a second threshold value RSSI _2 is checked, if yes, the node is considered to be a branch first node, and the father node of the node is a routing module. Wherein the second threshold value rssi _2 is the received signal strength between the node nearest to the routing module and the routing module obtained by actual test.

Specifically, as shown in fig. 3, in this embodiment, the node module implements the above steps S1 to S3 in a state machine manner, and there are 4 states: TOPO _ IDLE, TOPO _ START, TOPO _ PRE, TOPO _ ING. The 4 states are sequentially and circularly executed according to the sequence, and the specific circulating process is as follows:

1. and (5) a power-on initialization phase.

(1) And the node is added into the network of the routing module after being electrified, and receives a timing message sent by the routing module in a broadcasting mode for updating the local RTC real-time clock.

(2) After the node module is powered on, the RSSI received signal strength of the neighbor node is calculated by continuously monitoring messages sent by other nodes, and the average value in a period of time is calculated.

2. TOPO _ IDLE state.

(1) In this state, the program does not perform any operation, returns directly, and is in a wait state.

(2) When the program enters an NTB timed interrupt comparison interrupt processing function, a topology identification process starting mark is set, a voltage data acquisition command is sent to the corresponding intelligent electric meter through a serial port, and the program process enters a TOPO _ START state. And the electric meter receives the voltage data returned to the node module after receiving the command. And after receiving the voltage data, the node waits for a random delay, and then sends the voltage data to a power line to send one-hop local broadcast for other nodes to receive and process.

3. TOPO _ START state: and sequencing the RSSI of the neighbor nodes. And entering a TOPO _ PRE state after the sorting is finished.

4. TOPO _ PRE state: collecting voltage data broadcast by the neighbor nodes. Waiting for 10 seconds to finish collecting the voltage data of the neighbor nodes or receiving the broadcast messages of 100 nodes, and then entering the TOPO _ ING state.

5. TOPO _ ING state: parent node calculation and identification are performed as per step S3 described above. And after one-time topology calculation is finished, recording the address of the father node, counting the times and sequencing. And then returns to the TOPO _ IDLE state to wait for the next time the NTB timed interrupt compare interrupt handling function is entered.

And S4, after multiple identification, the node module takes the father node with the most statistical identification times as the father node of the node module and uploads the father node to the routing module.

And after each topology calculation is finished, recording the address of the father node, counting the times and sequencing. And after the multiple identification is completed, the node with the highest statistical frequency is the father node with the highest probability and is sent to the routing module.

And the routing module counts father node information of each node, and if a certain node is not the father node of any node, the node is a terminal leaf node. Topology learning begins at the end leaf node, and each line branch can be traversed in sequence through the superior-inferior relation of each node. If the two branches are finally converged to the same node or routing module, two branches are automatically formed. Therefore, a complete network topology graph can be drawn.

Example two

The second embodiment of the invention provides a distributed distribution network topology identification system based on measurement data, which is used for implementing the distributed distribution network topology identification method based on the measurement data in the first embodiment.

In summary, the present invention provides a distributed power distribution network topology identification method and system based on measurement data, which utilize each node to collect the measurement data of the electric meter and the received signal strength between the nodes, automatically calculate the father node of the node, and report the identification result to the routing module for statistics, thereby avoiding the defects of large centralized identification computation amount and excessive resource occupation. The invention does not need to add equipment, does not change the power grid environment, relies on power line communication for identification and has lower cost. In addition, the invention does not need to distinguish the topological branch of each node in advance, the routing module can automatically distinguish each branch path according to the father node reported by each node, thereby obtaining the topological graph of the whole transformer area, and the algorithm is simple and effective, thereby having stronger practicability.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A distributed distribution network topology identification method based on measurement data is characterized in that the distribution network comprises a distribution transformer, a concentrator, a routing module installed on the concentrator, an intelligent ammeter and a node module installed on the intelligent ammeter; the node module and the routing module realize data transceiving through HPLC communication, and the topology identification method comprises the following steps:

2. The method according to claim 1, wherein the step S3 specifically includes the following steps:

3. The method of claim 2, wherein the nodes that do not meet the condition in step S302 include nodes with node voltages lower than the voltage of the node, nodes with RSSI values greater than the first threshold, and nodes with no network access or RSSI values of zero.

4. The method of claim 3, wherein the first threshold is an RSSI value between nodes in a same meter box obtained through actual testing.

5. The method according to claim 2, wherein in step S301, when the number of nodes in the distribution grid area is less than N, all nodes are taken as parent nodes to be selected.

6. The method as claimed in claim 2, wherein in step S303, if the RSSI values of the nodes are the same and the maximum RSSI values are the same, the node with the maximum voltage is taken as the parent node of the current identification.

7. The method as claimed in claim 2, wherein in step S303, if there is no eligible parent node, it is determined whether RSSI received by the routing module by the node module is greater than a second threshold, and if yes, the routing module is used as the parent node of the current identification.

8. The method of claim 7, wherein the second threshold is an actual RSSI value between a node nearest to the routing module and the routing module.

9. The method as claimed in claim 1, wherein in the step S2, the node modules implement the steps S1-S3 by means of a state machine, and the state machine has 4 states: TOPO _ IDLE, TOPO _ START, TOPO _ PRE, TOPO _ ING, wherein:

10. A distributed distribution network topology identification system based on measured data, for implementing the distributed distribution network topology identification method based on measured data according to claim 1.