Research On Power System Network Topology Analysis Using Object-Oriented Technology

In modern power systems, energy control centers play a vital role in guaranteeing the security and optimal operation of a power network system. All kinds of analysis and calculation application in an energy control center, such as state estimation, optimal power flow (OPF), reactive power optimization, stability analysis and fault calculation, are based on the real-time model of the power system network along with the real-time data. And the expression of topology model decides the flexibility and the efficiency of the real-time analysis software. Reasonable topologyexpression could make the power network topology data be saved integrally and visited flexibly. This paper presents a method for power network topology analysis using Object-Oriented programming technique.There are two methods in traditional topology analysis: the tree search method and the matrix arithmetic method that based on a relation chart. Matrix arithmetic method is based on network's graph, design a special data configuration, it is commonly a relation chart that express the relationship between the node and other electric equipment. When the network topology changed, the matrix arithmetic method will trace the change by modify the relation chart through matrix calculation. The disadvantage of this method is that the model's generality and flexibility is not very well, and its calculation quantity is great. The tree search method is based on the graph; it includes Deep First Search (DFS) and Broad First Search (BFS). The process of DFS can be described as follow: from a node, along a route search other node until the end node, then select another route and repeat the aboveprocess until all nodes are searched. BFS is a kind of hierarchical search; the search process can be described as follow: from a node, take the node as a center, search other nodes around it from a layer to a layer.In this article, first, the object-oriented model of electric equipment was built, and then all the electric equipment C++ class property and behavior that relate to topology analysis was defined. The topology static analysis and dynamic tracing function were realized by BFS method. Basing the result of topology analysis, we can get all the electric equipments' running-state, and realized topology dynamic coloring base on their running-state and their voltage rate.The thesis has mainly finished the tasks as listed below:(1) The traditional topology analysis methods and graph theory knowledge were introduced, and their merits and faults were compared;(2) An Object-Oriented model of power system was formed. The model has the characteristics of bettergenerality and flexibility. It built a foundation for extending the software function and connecting to other power system application software;(3) BFS method was used to realize the topology static analysis and dynamic topology tracing. It used the visit technique of the MFC pointer-list in BFS process;(4) A timer was set to automatically control the breaker's operation; the change of network topology was traced when simulate the breaker's operation that include opening, reclosing and reopening;(5) This article realized the connection to power flow calculation software by dynamic create admittance matrix base the result of topology analysis.