The Algorithm Research Of Distribution State Estimation

Distribution Network State Estimation (DNSE) is one of the most important advanced applications in Distribution Management System (DMS). As a great help for analysis and decision making, DNSE can complete the information of a distribution system by estimating some un-gathered parameters from the obtained datum.As a foundation, the node voltage based power flow approach for distribution estimation is realized, which can not only used in radial networks, but also suitable for looped and grid ones.A distribution network can be divided into several parts. Based on the real information collected from the FTUs on the terminals of the part and the pseudo measurement datum embodying the statistic behavior of customers, three DNSE algorithms are investigated.A new DNSE algorithm which guaranteed the total belief level to be the highest is put forward.An increment least square algorithm based DNSE methodology is proposed, the index of which is improved, and an iterative approach is introduced to solve the non-linear problem.A genetic algorithm based DNSE method is presented. The appropriate index and constraint conditions are adopted. The profile of loads is represented by genes of standardized float coding. The multi-crossover and multi-mutation coordinately measure is utilized in the procedure.The proposed three DNSE algorithms are programmed on MATLAB 7.0.Comparisons are made on the described three DNSE approaches using typical examples. It is concluded that:The estimation results of maximum belief level DNSE is better than that of direct average value estimation. The estimation results of maximum belief level DNSE can be remarkably improved by increment least square algorithm based DNSE and genetic algorithm based DNSE. The estimation results of genetic algorithm based DNSE is the best. The...