Graph and model checking device and method based on medium-voltage carrier waves

Abstract

The invention belongs to the technical field of power system automation, and particularly relates to a graph model checking device and method based on medium-voltage carrier waves, the device comprises a carrier wave management machine, a fusion type PT and a fusion type FTU, and the method comprises the steps that a master station issues a graph model checking command through the carrier wave management machine, the fusion type FTU sends graph model signals after receiving the command, and the fusion type FTU sends the graph model signals to the master station; and the other fusion type FTUs sample graph model characteristic signals and upload sampling results to the carrier management machine, and the carrier management machine performs graph model drawing and uploads results to the power distribution automation master station. According to the method, accurate checking of the distribution line graph model can be quickly realized, the topology identification accuracy is improved, the manual intervention and updating times are reduced, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system automation, and in particular relates to a graphic model verification device and method based on a medium voltage carrier. Background Art

[0002] With the continuous development of distribution automation technology in my country, the verification of distribution line diagrams and models is of great significance in the power system. However, the existing technology has low efficiency in the verification of distribution line diagrams and models, frequent updates of distribution network topology, multiple maintenance versions, large model maintenance workload, and inconsistent diagrams and models, which seriously affect intelligent scheduling and cannot give full play to the practicality of distribution automation.

[0003] There are currently two main technical means to obtain the topology of the distribution network. The first is to use the medium-voltage feeder as a unit to retrieve the feeder data of the primary equipment in the distribution network (such as distribution network busbars, line segments, disconnectors, circuit breakers, fuses, and load switches, etc.) to form a set, and then connect these devices in sequence according to the connection point information of the primary equipment to form a static topology of the distribution network archive. The second is to determine the actual connected feeder based on voltage similarity, specifically to obtain the voltage data of the distribution transformer, the head end voltage of the feeder to which its archive belongs, and the head end voltage of the potential connected feeder, and use the Pearson correlation coefficient formula to calculate the correlation between the voltage data of the distribution transformer and the two outgoing line voltages, and select the potential connected feeder with the larger head end voltage similarity as the actual connected feeder.

[0004] Existing technologies are highly dependent on the accuracy of feeder data and connection point information. If the equipment archive data in the distribution network is erroneous, missing, or not updated in a timely manner, it will directly affect the accuracy of the construction of the topology base layer. In addition, existing technologies lack dynamic adaptability. Since a static topology is formed, it is difficult to adapt to the dynamic changes of equipment in the distribution network in real time. Once these changes occur, it is necessary to retrieve data and build the topology again, which may lead to a lag in topology updates. As the scale of the distribution network expands, the number and types of primary equipment increase, and it becomes more complicated to retrieve and process large amounts of feeder data and connection point information, increasing the maintenance cost and computational burden of the system. Summary of the invention

[0005] In view of the various deficiencies in the prior art, the inventors have researched and designed a pattern model verification device and method based on a medium-voltage carrier in long-term practice, aiming to solve the problems of low efficiency of distribution line pattern model verification and large maintenance workload in the prior art.

[0006] The present invention provides a medium voltage carrier-based image model verification device, comprising:

[0007] Carrier management machine: Use 10KV line to establish medium-voltage carrier communication channel. Based on the medium-voltage carrier communication channel and using medium-voltage carrier communication equipment, system dispatch and manage the carrier equipment connected to the 10KV line.

[0008] Fusion PT (Potential Transformer): The function of coupling the carrier signal to the 10KV line is integrated into the PT;

[0009] Fusion FTU (Field Termination Unit): includes a medium voltage carrier communication module and a graphic model verification module, and the graphic model verification module includes a graphic model sending module and a graphic model receiving module.

[0010] Furthermore, the communication module of the integrated FTU based on the medium voltage carrier establishes a connection with the FTU mainboard through a network cable.

[0011] The method for performing image model verification using the image model verification device of the present invention comprises the following steps:

[0012] (1) Install the fused FTU under each pole-mounted circuit breaker and connect it to it;

[0013] (2) Install the fused PT next to the pole-mounted circuit breaker and connect it to the fused FTU;

[0014] (3) Install the carrier management machine at any location of the 10kV distribution line and connect it to the distribution automation master station through parameter configuration;

[0015] (4) The master station issues a pattern verification command through the carrier management machine;

[0016] (5) After receiving the command, the fusion FTU sends the image and model signals respectively;

[0017] (6) Sample the pattern characteristic signal through other integrated FTUs installed on the line, and determine the upstream, branch line or downstream line of the integrated FTU based on the characteristics of the current flowing to the point with low impedance in the line;

[0018] (7) The sampling results are uploaded to the carrier management machine, which draws the model and uploads the drawing results to the distribution automation master station.

[0019] Furthermore, in step (5), the frequency of the image model signal is a low-frequency current signal of 425 Hz, 475 Hz, 625 Hz or 675 Hz.

[0020] Furthermore, in step (7), the graph drawing time is arbitrarily configured according to user needs and the number of topology identification nodes required, and the drawing time interval is at least once every 5 minutes.

[0021] The beneficial effects of the present invention are:

[0022] The model verification method based on medium-voltage carrier uses characteristic current signals to verify the model. The signal frequency is clear and the fused FTU is used to send and receive the model signal. This can accurately reflect the actual situation of the distribution line. At the same time, the position relationship of the fused FTU is judged according to the characteristics of the current flowing to the low-impedance point in the line, which further improves the accuracy of topology identification. It can quickly realize the accurate verification of the distribution line model, reduce the number of manual interventions and updates, and reduce maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the design principle of the image model verification device based on the medium voltage carrier of the present invention;

[0024] Figure 2 It is a connection schematic diagram of the device of the present invention after being hung on the network;

[0025] Figure 3 It is a schematic diagram of the design principle of the fusion PT of the present invention;

[0026] Figure 4 It is a schematic diagram of the flow of the module calibration signal of the present invention;

[0027] Figure 5 It is another schematic diagram of the flow of the model verification signal of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and implementation examples. These implementation examples are described in sufficient detail so that those skilled in the art can understand and practice the present invention. Without departing from the spirit and scope of the present invention, logical, achievable and other changes may be made to the implementation. Therefore, the following detailed description should not be construed as limiting, and the scope of the present invention is limited only by the claims.

[0029] See also Figure 1 , Figure 2 The present invention discloses a medium voltage carrier-based image model verification device, including a carrier management machine, a fused PT and a fused FTU.

[0030] The carrier management machine uses the 10KV line to establish a medium-voltage carrier communication channel. Based on the medium-voltage carrier communication channel and using medium-voltage carrier communication equipment, it performs system scheduling and management of the carrier equipment connected to the 10KV line.

[0031] Fusion PT: Based on the existing PT, it is redeveloped and has the function of coupling the carrier signal to the 10KV line integrated into the PT (see Figure 3 ).

[0032] The integrated FTU includes a medium voltage carrier communication module and a graphics verification module. The graphics verification module has a built-in graphics sending module and a graphics receiving module.

[0033] The working principle of the fusion FTU is as follows: the communication module based on the medium voltage carrier establishes a connection with the FTU mainboard through the network cable. The characteristic current signal required for the image model verification is sent to the 10KV side through the energy extraction coil of the fusion PT. After that, the fusion FTU running on the grid detects the transmitted characteristic current signal through the detection channel of the power frequency current, and transmits it to the medium voltage carrier image model verification unit through the network cable. Finally, this device transmits the image model signal to the carrier management machine with the help of the carrier channel, thereby completing the sorting of the image model signal.

[0034] The characteristic current transmission principle is to control IGBT (Insulated Gate Bipolar Transistor) through MCU (Microcontroller Unit) to put in and cut out a certain capacity of safety capacitor at a characteristic frequency (425Hz, 475Hz, 625Hz, 675Hz) on the secondary winding (220V) of PT, thereby generating a current signal with a characteristic frequency on the secondary side of PT. These signals are coupled to the primary side of the 10KV line through PT, and the characteristic signals are received by the fusion FTU equipment connected to the line.

[0035] See also Figure 4 , this figure shows the signal flow when the connection is disconnected. When the connection is in the disconnected state, the characteristic current of each node is sent out. Since the frequency of the transmitted current signal is low, the characteristic current will flow in the direction of the lowest line impedance. In the current power supply line, substation 01 and substation 02 are responsible for power supply, and the lowest impedance point of the line is located at the substation. Therefore, the characteristic signals of all nodes will be transmitted to these two substations along the 10KV line. When the characteristic current signal passes through each node, as long as the node can detect the characteristic current signal, then this node can be identified as the upstream of the current.

[0036] See also Figure 5 , this figure shows the signal flow when the connection is closed and the power supply of substation 02 is disconnected. When each node sends the characteristic current of the model, given the low frequency of the transmitted current signal, the characteristic current will follow the rule of flowing to the point with the lowest line impedance. For the current power supply line, only substation 01 presents the lowest impedance. Therefore, the characteristic current signals of all nodes will be transmitted to substation 01 along the 10KV line. In the process of the characteristic current signal transmitting through each node, as long as a node can successfully detect the characteristic current signal, then this node can be determined as the upstream of the current.

[0037] When pattern verification is required, the carrier management machine issues a pattern verification command, and the integrated FTU on the line uploads the pattern information from each node to the carrier management machine through the medium-voltage carrier system. The carrier management machine performs statistical analysis to achieve verification of the distribution line.

[0038] In addition, the graph drawing time can be arbitrarily configured according to user needs and the number of topology identification nodes required, and the minimum drawing time interval can be up to 5 minutes.

[0039] See also Figure 2 , using the image model verification device of the present invention to perform an image model verification method, comprising the following steps:

[0040] (1) Install the fused FTU under each pole-mounted circuit breaker as required and connect it to it.

[0041] (2) Install the fused PT next to the pole-mounted circuit breaker and connect it to the fused FTU to provide power supply and voltage sampling signal for the fused FTU.

[0042] (3) Install the carrier management machine at any location on this 10kV distribution line and connect it to the distribution automation master station through parameter configuration.

[0043] (4) The master station sends a graphics model verification command through the carrier management machine.

[0044] (5) After receiving the command, the fusion FTU sends the graphic signal respectively. The graphic signal frequency is a low-frequency current signal of 425Hz, 475Hz, 625Hz, and 675Hz.

[0045] (6) Sample the pattern characteristic signal through other integrated FTUs installed on the line, and determine the upstream, branch line or downstream line of the integrated FTU based on the characteristics of the current flowing to the point with low impedance in the line.

[0046] (7) The sampling results are uploaded to the carrier management machine, which draws the model and uploads the drawing results to the distribution automation master station. The model drawing time can be arbitrarily configured according to user needs and the number of topology identification nodes required; the minimum drawing time interval can be up to 5 minutes.

[0047] The model verification method based on medium-voltage carrier of the present invention can quickly realize the accurate verification of distribution line model. When model verification is required, after the carrier management machine issues a command, the fused FTU can quickly upload the model information from each node to the carrier management machine through the medium-voltage carrier system for statistical analysis, which greatly shortens the model verification time and improves work efficiency. However, the traditional technology uses medium-voltage feeder as a unit to retrieve data to form a collection and then connect the equipment in sequence. The process is relatively cumbersome and time-consuming.

[0048] The present invention uses characteristic current signals to perform pattern verification, the signal frequency is clear (425Hz, 475Hz, 625Hz, 675Hz), and the fused FTU is used to send and receive pattern signals, which can accurately reflect the actual situation of the distribution line. At the same time, the position relationship of the fused FTU is judged according to the characteristics of the low impedance point in the current flow line, further improving the accuracy of topology recognition.

[0049] Traditional technology determines the actual connected feeder based on voltage similarity, and uses the Pearson correlation coefficient formula to calculate the correlation to determine the connection relationship. This method may be affected by factors such as voltage fluctuations, and the accuracy is relatively low. Traditional technology is relatively fixed in time configuration and it is difficult to meet diverse needs. The present invention can arbitrarily configure the graph drawing time according to user needs and the number of topology identification nodes required, and the minimum drawing time interval can reach once every 5 minutes. This enables the technology to better meet application needs in different scenarios and has higher flexibility. Traditional technology requires the retrieval of a large amount of data and manual connection and analysis, and the maintenance workload is large. The technical system based on medium-voltage carrier can automatically check and draw the graph, reducing the number of manual interventions and updates, and reducing maintenance costs.

[0050] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A pattern verification device based on medium voltage carrier, characterized in that: include Carrier management machine: Use 10KV line to establish medium-voltage carrier communication channel. Based on the medium-voltage carrier communication channel and using medium-voltage carrier communication equipment, system dispatch and manage the carrier equipment connected to the 10KV line. Fusion PT: The function of coupling the carrier signal to the 10KV line is integrated into the PT; Fusion FTU: includes medium voltage carrier communication module and image model verification module. The image model verification module includes image model sending module and image model receiving module.

2. The device according to claim 1, characterized in that The communication module of the integrated FTU based on the medium voltage carrier is connected to the FTU mainboard through a network cable.

3. A method for image model verification using the device of claim 1, characterized in that: The following steps are involved: (1) Install the fused FTU under each pole-mounted circuit breaker and connect it to it; (2) Install the fused PT next to the pole-mounted circuit breaker and connect it to the fused FTU; (3) Install the carrier management machine at any location of the 10kV distribution line and connect it to the distribution automation master station through parameter configuration; (4) The master station issues a pattern verification command through the carrier management machine; (5) After receiving the command, the fusion FTU sends the image and model signals respectively; (6) Sample the pattern characteristic signal through other integrated FTUs installed on the line, and determine the upstream, branch line or downstream line of the integrated FTU based on the characteristics of the current flowing to the point with low impedance in the line; (7) The sampling results are uploaded to the carrier management machine, which draws the model and uploads the drawing results to the distribution automation master station.

4. The method according to claim 3, characterized in that In step (5), the frequency of the image model signal is a low-frequency current signal of 425 Hz, 475 Hz, 625 Hz or 675 Hz.

5. The method according to claim 3, characterized in that: In step (7), the graph drawing time is arbitrarily configured according to user needs and the number of topology identification nodes required.

6. Use of the method according to claim 5, characterized in that In step (7), the drawing interval is at least once every 5 minutes.

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