Research On Fast Identification Of Power Network Topology Analysis

As the the basis of many power system analysis software, analysis of electric power network topology is used to transform the physical model of electric power system into the mathematical model of the network analysis, which can provide the data of the network structure for the power flow calculation, the state estimation, and safety analysis..Therefore, for the modern increasingly complex power system, we need more fast and accurate analysis algorithms for the power system network topology in order to ensure operate safely and economic ly.It can guarantee the efficiency of topology analysis to use hierarchical distributed network topology modeling method, which namely analysis each substation topology simultaneously, and then extend to the other stations and even the whole system. In addition, crossing checking electrical quantity and the switch quantity with the information of PMU, which is of high sampling frequency and good synchronization, can further improve the reliability of the power system network topology analysis:(1) In allusion to the defects of traditional method for the formation of topology inside substation and its updating efficiency, based on topological basis and radius search method a new method for the analysis on topology inside substation is proposed. Firstly, the node numbering is performed by basic concept of the graph theory and the circuit breakers are represented by nodes; on this basis, combining with the features of main electrical connection and the information of closed circuit breakers and utilizing the theorem of topological base the analysis on topology inside substation is performed. When circuit breaker status changes, based on radius search method the varied topology is modified to avoid the low updating velocity due to topology reformation, thus the efficiency of substation topology to trace the varied circuit breaker states can be evidently improved and the calculated amount of the proposed method is less than traditional methods. The validity of the proposed method is validated by experimental results.(2) According to the requirement of instantaneity and accuracy on the network topology analysis to the power system analysis software, this paper puts forward a new method of network topology analysis. Under normal circumstances, form the initial distribution of electrical islands by notation of the incidence matrix. At the same time, mark tree and link lines. When switches of network displacing, use the loop matrix method, which is formed based on the tree and link branches during the analysis of the steady state network topology. Firstly, judge the form of the changing branch. On the basis, modify the local topology of network and update the loop matrix with the further aid of broken circle method and the radius search method. Finally, using programming validates the quickness of the notation the incidence matrix. And this method is of lower computational complexity, rapidly updating, applied to variable network structure by the example of the IEEE-39bus system(3) This paper proposes a topology error detection method based on the road-loop equation. The method calculates the branch current using synchronization electric parameters provided by phasor measurement unit (PMU) through the road-loop equation. And then analysis the difference between the value of calculated and measured under different conditions, which can be used to judge whether the circuit topology errors or bad data exist. If there are some mistakes, modify topology errors and bad data according to the difference. Finally, with IEEE9and IEEE39system simulation show that the method is of adaptability, reliability, and good fault tolerance.