High-speed Distributed Process State Estimate Algorithm Based On Graph Theory

With the increasing national power generation capacity, increasing the size of the grid, grid operation methods have become more complex, relatively speaking, the power system security and stability to a certain degree of decline. Disturbance may cause serious blackouts or even the whole network crashes, resulting in catastrophic consequences, security and stability to the grid which raised new challenges. Therefore, the study of high-speed power system state estimation algorithm has very important significance.Based on the structural characteristics of the power system and the actual operation, based on graph theory algorithm for a distributed state estimation method, from the decomposition of the network in order to improve the network model of distributed computing and two-pronged approach of improving the WLS state estimation accuracy of the method, Algorithm based on graph theory to establish a network decomposition model constructed by the principles of graph theory, minimum spanning tree decomposition of the grid, will be broken down into easy to compute a large grid of small networks, and through the adaptive algorithm for state estimation. Adaptive algorithm proposed in this paper a process state estimation algorithm, the basic idea is, the weak-link ring network solution, and then the leaves from the tree node (or leaf node where the branch) to the upper iterative weighted least squares state estimated that the lower estimate, as the pseudo-measurements, applied to the upper estimate. While taking advantage of push back on behalf of the former method of calculation, Weighted least squares method of initial weight by the power systems of statistical measurement equipment, the decision rule, usually taking the inverse of the variance of measurement as weights, From a statistical point of law, once for each estimate, the resulting estimates have a greater chance than the original value closer to the true value.To illustrate the effectiveness of research, this paper IEEE118 bus system for the simulation and analysis, break through the design of different network solutions, analysis of the reliability and validity of this algorithm.