CN105449676B - Power distribution network Area Node network generation method and system - Google Patents

Abstract

The invention provides a distribution network regional node network generation method and system, which constructs a CIM tree topology structure, eliminates virtual branches in the CIM tree topology structure, and merges transformer winding branches belonging to the same double-winding transformer into a Single transformer branch, obtain electrical tree topology, according to the switch branch, divide the electrical tree topology into multiple mutually independent regions, and use each mutually independent region as a single node, obtain multiple regional nodes, and restore the switch The connection relationship between branches among multiple regional nodes is obtained to obtain the regional node network. In the whole process, based on the CIM model, the regional node network is obtained through the contraction of the CIM topology and the electrical topology, and the highly simplified regional node network is obtained, and the contribution of the internal equipment in the regional node network to the reliability of the distribution network is obtained Similarly, it can greatly reduce the calculation scale and improve the calculation efficiency without affecting the reliability calculation of the distribution network.

Description

Distribution network regional node network generation method and system

technical field

The invention relates to the technical field of distribution network, in particular to a method and system for generating a regional node network of a distribution network.

Background technique

The distribution network is composed of overhead lines, cables, towers, distribution transformers, isolating switches, reactive power compensation capacitors, and some ancillary facilities. It plays an important role in distributing electric energy in the power network. The topology analysis of the power distribution network is based on the connection relationship of the distribution electrical components, and the entire power distribution network is regarded as a topological diagram combining lines and points, and then the topological connection analysis of the entire network is carried out according to the power supply nodes, switch nodes, etc. It is the basis for state estimation, power flow calculation, fault location, isolation and power restoration, network reconfiguration and other analysis of power distribution network.

The reliability analysis of the distribution network is still at the level of offline analysis, and relatively speaking, the requirements for its calculation speed are not high. With the continuous deepening of smart grid construction, modern society has higher and higher requirements for the reliability of power supply, and the reliability analysis of distribution network has transitioned from traditional offline analysis to online analysis. The computational performance requirements of the system are very high, and a major breakthrough in distribution network reliability modeling is required.

The data for distribution network reliability analysis and calculation is based on distribution network regional node network. If an accurate and simplified distribution network regional node network can be provided, it will be able to effectively reduce the scale of distribution network reliability analysis and calculation and improve the reliability of distribution network. Computational efficiency.

Contents of the invention

Based on this, it is necessary to provide a method and system capable of generating an accurate and simplified distribution network regional node network for the problem that there is currently no accurate and simplified distribution network regional node network.

A method for generating a regional node network of a distribution network, comprising the steps of:

Build a CIM (Common Information Model, Common Information Model) tree topology, wherein the CIM tree topology includes virtual branches and switch branches;

Eliminate virtual branches and merge transformer winding branches belonging to the same double-winding transformer in the CIM tree topology into a single transformer branch to obtain an electrical tree topology;

According to the switch branch, the electrical tree topology is divided into multiple mutually independent regions, and each mutually independent region is regarded as a single node to obtain multiple regional nodes;

The connection relationship between switch branches among multiple regional nodes is restored, and the regional node network is obtained.

A distribution network regional node network generation system, comprising:

A building block for constructing a CIM tree topology, wherein the CIM tree topology includes a virtual branch and a switch branch;

The electrical structure acquisition module is used to eliminate the virtual branch and merge the transformer winding branches belonging to the same double-winding transformer in the CIM tree topology into a single transformer branch to obtain the electrical tree topology;

The regional node acquisition module is used to divide the electrical tree topology into multiple mutually independent regions according to the switch branch, and use each mutually independent region as a single node to obtain multiple regional nodes;

The regional node network acquisition module is used to restore the connection relationship between switch branches among multiple regional nodes, and obtain the regional node network.

The method and system for generating the regional node network of the distribution network in the present invention constructs a CIM tree topology structure, eliminates virtual branches in the CIM tree topology structure, and merges transformer winding branches belonging to the same double-winding transformer into a single transformer branch According to the switch branch, the electrical tree topology is divided into multiple mutually independent regions, and each mutually independent region is used as a single node to obtain multiple regional nodes, and the switch branch is restored in A connection relationship among multiple regional nodes is obtained to obtain a regional node network. In the whole process, based on the CIM model, the regional node network is obtained through the contraction of the CIM topology and the electrical topology, and the highly simplified regional node network is obtained, and the contribution of the internal equipment in the regional node network to the reliability of the distribution network is obtained Similarly, it can greatly reduce the calculation scale and improve the calculation efficiency without affecting the reliability calculation of the distribution network.

Description of drawings

Fig. 1 is a schematic flow chart of the first embodiment of the distribution network regional node network generation method of the present invention;

Fig. 2 is a schematic flow chart of the second embodiment of the distribution network regional node network generation method of the present invention;

Fig. 3 is a schematic diagram of a CIM tree topology of a distribution network feeder;

Fig. 4 is a schematic structural diagram of the first embodiment of the distribution network regional node network generation system of the present invention;

Fig. 5 is a schematic structural diagram of a second embodiment of the distribution network regional node network generation system of the present invention.

Detailed ways

In order to facilitate the explanation of the technical solution of the distribution network regional node network generation method and system of the present invention and the effects brought by it, the basic principles of its application will be described in detail below.

In the power system, for the sake of information interaction and functional integration, more and more applications follow the CIM specification recommended by the IEC (International Electrotechnical Commission, International Electrotechnical Commission) organization when transmitting and using data. A distribution network feeder model conforming to the CIM specification is often carried by the corresponding XML (Extensive Markup Language, Extensible Markup Language) string, which contains the most complete information of the distribution network feeder model, such as the topology of the feeder, equipment Type, basic parameters, geographic location, etc. At present, the construction of the distribution network often has loops, but the loops are broken during operation. That is to say, a single feeder often has a connection relationship with other feeders, but this connection relationship is disconnected during normal operation. It can be seen that the CIM model of a single feeder should be a strict tree topology.

Since the CIM model of the distribution network feeder is the most complete, in fact all the information may not be needed in different occasions. Specifically, the objectively existing electrical equipment in the CIM model will not be directly connected, but needs to establish a connection relationship through the contact node object and the terminal node object. These two objects are only objects at the logical level. In the objective world, they are nonexistent. When performing power flow calculation, short circuit calculation, reliability calculation and other analysis and calculation of distribution network, there is no need for contact node objects and terminal node objects, which need to be simplified. By analyzing the definition of the topology structure of CIM, it can be seen that the terminal nodes associated with each contact node can be found, and all the electrical equipment directly connected to the terminal nodes can be connected to the same electrical point, that is, the connection between the contact nodes and the terminal nodes can be realized. Shrink Simplify. The different windings of the transformer are independent objects in the CIM model and are also connected through contact nodes and terminal nodes. When performing various analysis calculations, it is necessary to consider multiple windings of the transformer as a whole. The transformers involved in the 10kV medium-voltage distribution network are all double-winding transformers. When shrinking and simplifying the contact node and terminal node, when encountering a double-winding transformer, the two windings belonging to the same transformer can be directly combined to form A branch, so as to realize the contraction and simplification of the double-winding transformer.

After the above analysis, the electrical topology model of the distribution network can be obtained. At present, this electrical topology model can be used for the power flow calculation and short circuit calculation of the distribution network. The currently obtained distribution network electrical topology includes all electrical equipment directly related to power transmission, such as transmission lines, transformers, switch branches, etc. As mentioned above, when performing reliability calculations, only the response time of various switch branches to faults needs to be considered, and the internal equipment parameters and topological relationships of the multiple connected areas divided by switch branches have an impact on reliability. Contributions are poolable.

As shown in Figure 1 and Figure 2, a method for generating a distribution network regional node network includes steps:

S100: Construct a CIM tree topology structure, wherein the CIM tree topology structure includes virtual branches and switch branches.

CIM is an abstract model used to describe all main objects of electric power enterprises, especially those related to electric power operation. By providing a standard method of representing power system resources with object classes and attributes and their relationships, CIM facilitates the integration of energy management system applications independently developed by different vendors, and the integration of multiple independently developed complete energy management systems. The integration between energy management systems and other systems involved in different aspects of power system operation enables these applications or systems to access common data and exchange information independently of the internal representation of information. The CIM tree topology includes two parts: nodes and branches. The endpoints include contact nodes and terminal nodes, and the branches include virtual branches, AC line segments, transformer windings, and switch branches. Virtual branches are used to represent the logical connection relationship of electrical equipment. As shown in Figure 3, the CIM tree topology structure of the distribution network feeder, in which the nodes are contact nodes and terminal nodes, a total of 1642, the branch includes the virtual branch between the contact node and the terminal node, AC line section, transformer There are 1641 windings and various switch branches.

Specifically, in one of the embodiments, step S100 includes:

S120: Obtain a standard CIM model of a distribution network feeder.

S140: Map the standard CIM model of the distribution network feeder into a CIM tree topology.

The standard CIM model of the distribution network feeder is a basic model known in the power system industry. Specifically, the standard CIM model of the distribution network feeder can be mapped into a CIM tree topology.

S200: Eliminate virtual branches, and merge transformer winding branches belonging to the same double-winding transformer in the CIM tree topology into a single transformer branch to obtain an electrical tree topology.

In the CIM tree topology, the contact nodes and terminal nodes only have logical meanings, and there are no entities in the physical environment, and their information is not needed for various electrical analysis, which can be contracted and simplified. In the CIM model, each transformer winding is an independent object. In the electrical topology, the two transformer winding objects belonging to the unified double-winding transformer should be merged into the same transformer branch, and it should be shrunk and simplified.

S300: Divide the electrical tree topology structure into multiple mutually independent areas according to the switch branches, and use each mutually independent area as a single node to obtain multiple area nodes.

In the CIM tree topology, the switch branch can be obtained. According to the switch branch in the feeder, the electrical tree topology is divided into multiple independent areas, and each area is merged into a node, that is, the area node is obtained.

S400: Restoring the connection relationship between the switch branches among multiple regional nodes to obtain a regional node network.

Restoring the connection relationship between switch branches among regional nodes, the final regional node network is obtained. Compared with the standard CIM model, the regional node network obtained by the distribution network regional node network generation method of the present invention is highly simplified without losing the accuracy of reliability calculation.

The distribution network regional node network generation method of the present invention constructs a CIM tree topological structure, eliminates virtual branches in the CIM tree topological structure, and merges transformer winding branches belonging to the same double-winding transformer into a single transformer branch, Obtain the electrical tree topology structure, divide the electrical tree topology structure into multiple independent areas according to the switch branch, and use each independent area as a single node, obtain multiple area nodes, and restore the switch branch in multiple The connection relationship between the regional nodes is used to obtain the regional node network. In the whole process, based on the CIM model, the regional node network is obtained through the contraction of the CIM topology and the electrical topology, and the highly simplified regional node network is obtained, and the contribution of the internal equipment in the regional node network to the reliability of the distribution network is obtained Similarly, it can greatly reduce the calculation scale and improve the calculation efficiency without affecting the reliability calculation of the distribution network.

As shown in Figure 2, in one embodiment, step S400 includes:

S420: Obtain electrical nodes at both ends of each switch branch respectively.

Specifically, firstly, the switch branch is obtained from the CIM tree topology. For the convenience of recording, the obtained switch branch can be constructed as a switch branch set S _Br , and the switch branch set S _Br includes multiple switch branches Br. Then obtain the electrical nodes of the two points of each switch branch Br.

S440: Identify the connected subgraph to which the electrical nodes at both ends of each switch branch belong.

Specifically, the connectivity in the CIM tree topology can be judged first, and all connected subgraphs and node objects of the connected subgraphs in the CIM tree topology can be found. In the found connected subgraph, identify the connected subgraph to which the electrical nodes at both ends of each switch branch Br belong.

S460: Find the region nodes of the connected subgraph to which the electrical nodes at both ends of each switch branch belong in the plurality of region nodes.

Among the multiple area nodes obtained in step S300 , search for the area nodes of the connected subgraph to which the electrical nodes at both ends of each switch branch Br belong.

S480: Connect the found regional nodes through corresponding switch branches to obtain a regional node network.

The regional node network is obtained by connecting the regional nodes of the connected subgraph to which the electrical nodes at both ends of the switching branch Br belong through the switching branch Br.

In one of the embodiments, the CIM tree topology includes contact nodes and terminal nodes, and the step of eliminating the virtual branch in the CIM tree topology includes:

Traverse the CIM tree topology structure, obtain the contact nodes in the CIM tree topology structure, take each contact node as the research object, and perform the following operations respectively: find the virtual branch connected to a single contact node, obtain the virtual branch set, record The terminal node on the opposite side of each virtual branch in the virtual branch set obtains the virtual branch terminal node set, deletes the virtual branch in the virtual branch set, and uses the terminal node in the virtual branch terminal node set as the end point of the branch The path is modified to use a single contact node as the corresponding end point, and the modified end node is deleted.

An example will be used below to explain in detail the process of eliminating the virtual branch.

1. First enumerate and obtain a contact node set S _c composed of all contact nodes in the CIM topology.

2. Perform the following operations on each element c in the set S _c :

2.1. In the CIM topology, traverse to obtain all the virtual branches connected to the contact node c, record the set S _ct ^(c) of all these virtual branches, and the set S _t of the opposite terminal nodes of each virtual branch ^(c) .

2.2. Delete all virtual branches in the set S _ct ^(c) .

2.3 Change all the branches with the terminal node in S _t ^(c) as the terminal to c as the corresponding terminal, and delete this terminal node.

In one of the embodiments, the step of merging the transformer winding branches belonging to the same double-winding transformer in the CIM tree topology into a single transformer branch includes:

According to the CIM tree topology structure, enumerate the transformer virtual nodes in the CIM tree topology structure, take a single transformer virtual node as the research object, and perform the following operations respectively: traverse the CIM tree topology structure, and obtain two virtual nodes connected to a single transformer Transformer winding branch, calculate the parameter information after the two transformer winding branches are merged, generate a single branch between the nodes on the opposite side of the two transformer winding branches, and assign the corresponding parameter value of the single branch according to the parameter information, delete the two transformer winding branches and a single transformer virtual node.

An example will be used below to explain in detail the process of merging transformer winding branches belonging to the same double-winding transformer in the CIM tree topology into a single transformer branch.

1. Enumerate and obtain the transformer set S _t composed of all transformer virtual nodes in the CIM topology.

2. Perform the following operations on each element t in the set S _t :

2.1. Traverse the original CIM topology to obtain two transformer winding branches connected to the virtual node t of the transformer.

2.2. Calculate various parameter information after the two transformer winding branches just found are merged.

2.3. Generate a branch between the nodes on the opposite side of the two transformer winding branches, and assign corresponding parameter values.

2.4. Delete two transformer winding branches and transformer virtual node t.

As shown in Figure 4, a distribution network regional node network generation system includes:

The construction module 100 is used to construct the CIM tree topology.

The electrical structure acquisition module 200 is used to eliminate the virtual branches in the CIM tree topology, and merge the transformer winding branches belonging to the same double-winding transformer in the CIM tree topology into a single transformer branch to obtain the electrical tree topology. Topology.

The regional node acquisition module 300 is configured to divide the electrical tree topology into multiple mutually independent regions according to the switch branches in the CIM tree topology, and use each mutually independent region as a single node to obtain multiple regional nodes .

The regional node network acquisition module 400 is configured to restore the connection relationship between switch branches among multiple regional nodes, and obtain the regional node network.

In the distribution network regional node network generation system of the present invention, the construction module 100 constructs a CIM tree topology structure, and the electrical structure acquisition module 200 eliminates the virtual branches in the CIM tree topology structure, and the transformer winding branches belonging to the same double-winding transformer Circuits are merged into a single transformer branch to obtain an electrical tree topology, and the regional node acquisition module 300 divides the electrical tree topology into multiple mutually independent regions according to the switch branch, and regards each mutually independent region as a single node, After obtaining multiple regional nodes, the regional node network acquisition module 400 restores the connection relationship between the switch branches among the multiple regional nodes, and obtains the regional node network. In the whole process, based on the CIM model, the regional node network is obtained through the contraction of the CIM topology and the electrical topology, and the highly simplified regional node network is obtained, and the contribution of the internal equipment in the regional node network to the reliability of the distribution network is obtained Similarly, it can greatly reduce the calculation scale and improve the calculation efficiency without affecting the reliability calculation of the distribution network.

As shown in Figure 5, in one of the embodiments, the regional node network acquisition module 400 includes:

The electrical node acquiring unit 420 is configured to respectively acquire the electrical nodes at both ends of each switch branch.

The identifying unit 440 is configured to identify the connected subgraph to which the electrical nodes at both ends of each switch branch belong.

The search unit 460 is configured to search the regional nodes of the connected subgraph to which the electrical nodes at both ends of each switch branch belong among the multiple regional nodes.

The regional node network acquiring unit 480 is configured to connect the searched regional nodes through corresponding switch branches to obtain the regional node network.

As shown in Figure 5, in one of the embodiments, the building block 100 includes:

A standard model obtaining unit 120, configured to obtain a standard CIM model of the distribution network feeder.

The construction unit 140 is configured to map the standard CIM model of the distribution network feeder into a CIM tree topology.

In one of the embodiments, the CIM tree topology includes contact nodes and terminal nodes;

The electrical structure acquisition module 200 includes:

The first traversal unit is used to traverse the CIM tree topology and obtain the contact nodes in the CIM tree topology.

The first repeating unit, taking each contact node as the research object, respectively controls the following units to perform corresponding operations.

The virtual branch search unit is configured to search for virtual branches connected to a single contact node to obtain a set of virtual branches.

The virtual branch terminal node obtaining unit is configured to record the terminal node on the opposite side of each virtual branch in the virtual branch set, and obtain the virtual branch terminal node set. ;

The first deleting unit is configured to delete a virtual branch in the virtual branch set.

The modifying unit is configured to modify a branch whose endpoint is a terminal node in the virtual branch terminal node set to a single contact node as a corresponding endpoint, and delete the modified terminal node.

In one of the embodiments, the electrical structure obtaining module 200 also includes:

The transformer virtual node acquisition unit is configured to enumerate and obtain the transformer virtual nodes in the CIM tree topology according to the CIM tree topology.

The second repeating unit is used to take a single transformer virtual node as the research object, and respectively control the following units to perform corresponding operations.

The second traversal unit is configured to traverse the CIM tree topology to obtain two transformer winding branches connected to a single transformer virtual node.

The parameter calculation unit is used to calculate the parameter information after the two transformer winding branches are merged.

The parameter assigning unit is used to generate a single branch between nodes on opposite sides of the two transformer winding branches, and assign corresponding parameter values to the single branch according to parameter information.

The second deletion unit is used to delete two transformer winding branches and a single transformer virtual node.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (8)

1. a kind of power distribution network Area Node network generation method, it is characterised in that including step：

CIM tree topologies are built, wherein, the CIM tree topologies include virtual tributary and switching branches；

The virtual tributary is eliminated, and the transformer that same two-winding transformer will be belonged in the CIM tree topologies Winding branch road is merged into wall scroll transformer branch, obtains electric tree topology；

According to the switching branches, the electrically tree topology is divided into multiple separate regions, and by each institute Separate region is stated as individual node, obtains multiple Area Nodes；

Recover annexation of the switching branches between the multiple Area Node, obtain Area Node network；

The annexation for recovering the switching branches between the multiple Area Node, the step of obtaining Area Node network Including：

The electrical node at every switching branches both ends is obtained respectively；

Identify every affiliated connected subgraph of switching branches both ends electrical node；

The region section of every affiliated connected subgraph of switching branches both ends electrical node is searched in the multiple Area Node Point；

The Area Node arrived by the corresponding switching branches connection and locating, obtains Area Node network.

2. power distribution network Area Node network generation method according to claim 1, it is characterised in that the structure CIM trees The step of shape topological structure, includes：

Obtain the standard CIM of distribution feeder；

The standard CIM of the distribution feeder is mapped to CIM tree topologies.

3. power distribution network Area Node network generation method according to claim 1 or 2, it is characterised in that the CIM is tree-shaped Topological structure also includes contact node and terminal node；

Described the step of eliminating the virtual tributary, includes：

The CIM tree topologies are traveled through, obtain the contact node in the CIM tree topologies；

Using each contact node as research object, proceed as follows respectively；

The virtual tributary being connected with the single contact node is searched, obtains virtual tributary set；

The terminal node of every virtual tributary offside in the virtual tributary set is recorded, obtains virtual tributary terminal Node set；

Delete the virtual tributary in the virtual tributary set；

To be the leg modifications of end points for the single institute using terminal node described in the virtual tributary terminal node set It is corresponding end points to state contact node, and deletes the terminal node changed.

4. power distribution network Area Node network generation method according to claim 1 or 2, it is characterised in that described by described in The Transformer Winding branch road for belonging to same two-winding transformer in CIM tree topologies is merged into the step of wall scroll transformer branch Suddenly include：

According to the CIM tree topologies, enumerate to obtain transformer dummy node in the CIM tree topologies；

Using the single transformer dummy node as research object, proceed as follows respectively；

The CIM tree topologies are traveled through, obtain two transformers being connected with the single transformer dummy node Winding branch road；

Calculate the parameter information after two Transformer Winding branch roads merge；

In two Transformer Winding branch roads generating wall scroll branch road side gusset, and according to being assigned to the parameter information Wall scroll branch road corresponding parametric values；

Delete two Transformer Winding branch roads and the single transformer dummy node.

5. a kind of power distribution network Area Node network generates system, it is characterised in that including：

Module is built, for building CIM tree topologies, wherein, the CIM tree topologies include virtual tributary and opened Close branch road；

Electrical structure acquisition module, for the virtual tributary to be eliminated, and it will belong to same in the CIM tree topologies The Transformer Winding branch road of two-winding transformer is merged into wall scroll transformer branch, obtains electric tree topology；

Area Node acquisition module, for according to the switching branches, the electrically tree topology to be divided into multiple phases Mutual isolated area, and each region independently of each other as individual node, is obtained into multiple Area Nodes；

Area Node Network Capture module, for recovering annexation of the switching branches between the multiple Area Node, Obtain Area Node network；

The Area Node Network Capture module includes：

Electrical node acquiring unit, for obtaining the electrical node at every switching branches both ends respectively；

Recognition unit, for identifying every affiliated connected subgraph of switching branches both ends electrical node；

Searching unit, for searching connection belonging to every switching branches both ends electrical node in the multiple Area Node The Area Node of subgraph；

Area Node Network Capture unit, for the Area Node arrived by the corresponding switching branches connection and locating, obtain Area Node network.

6. power distribution network Area Node network according to claim 5 generates system, it is characterised in that the structure module bag Include：

Master pattern acquiring unit, for obtaining the standard CIM of distribution feeder；

Construction unit, for the standard CIM of the distribution feeder to be mapped into CIM tree topologies.

7. the power distribution network Area Node network generation system according to claim 5 or 6, it is characterised in that the CIM is tree-shaped Topological structure also includes contact node and terminal node；

The electrical structure acquisition module includes：

First Traversal Unit, for traveling through the CIM tree topologies, obtain the contact in the CIM tree topologies Node；

First repeat unit, using each contact node as research object, control such as lower unit carries out corresponding operating respectively；

Virtual tributary searching unit, for searching the virtual tributary being connected with the single contact node, obtain virtual branch Gather on road；

Virtual tributary terminal node acquiring unit, for recording in the virtual tributary set every virtual tributary offside The terminal node, obtain virtual tributary terminal node set；

First deletes unit, for deleting the virtual tributary in the virtual tributary set；

Unit is changed, for that will be using leg modifications of the terminal node as end points described in the virtual tributary terminal node set Using the single contact node as corresponding end points, and delete the terminal node changed.

8. the power distribution network Area Node network generation system according to claim 5 or 6, it is characterised in that the electrically knot Structure acquisition module also includes：

Transformer dummy node acquiring unit, for according to the CIM tree topologies, enumerating to obtain, the CIM is tree-shaped to be opened up Flutter transformer dummy node in structure；

Second repeat unit, for using the single transformer dummy node as research object, control such as lower unit to be carried out respectively Corresponding operating；

Second Traversal Unit, for traveling through the CIM tree topologies, acquisition two is virtual with the single transformer The connected Transformer Winding branch road of node；

Parameter calculation unit, for calculating the parameter information after two Transformer Winding branch roads merge；

Parameter given unit, in two Transformer Winding branch roads generating wall scroll branch road side gusset, and according to institute State parameter information and be assigned to the wall scroll branch road corresponding parametric values；

Second deletes unit, for deleting two Transformer Winding branch roads and the single transformer dummy node.