Research On State Estimation And Measurement Configuration For Distribution System With A Few Spots

Distribution automation is the only way for the development of distribution system.The state estimation is the basic of distribution application software.If no in-depth study on distribution state estimation,it will result in resources waste of other advanced application software and existing hardware.The status and the basic theory of the classical distribution network state estimation were described,the characteristics of distribution system state estimation were analyzed,and the state estimation algorithms commonly used in distribution network were compared in the paper.Taking the small amount of measured spots in distribution network into account,a branch-power-based state estimation algorithm in distribution system with a few measured spots was proposed.The radial characteristics and the linear relationship between branch power and load power in distribution system were made full use of.The efficiency of estimation is improved,with online application prospects;the historical load data were used as pseudo-measurement to replenish the measurement.Weighted least squares criterion was used to restrain low accuracy of pseudo-measurement from affecting the precision of estimation results.It gets a real distribution system state.It is almost impossible to install measurement at each node for large-scale distribution network,so the limited measurement devices are wanted to be made to play a better role.In this paper,taboo search algorithm was used for the optimization of measurement device type and location.Heuristic algorithm is used to sort the measurement by their sensitivity to get better initial solution.Taboo table is used to avoid the search cycle.It plays a very good role in guiding measurement configuration in distribution system.The above methods are demonstrated with IEEE-33 bus distribution system.Test results indicate that the proposed algorithm can improve the accuracy of state estimation,and play a very good guide for measurement configuration in planning distribution system.