Research On State Estimation Method Of Distribution Network Operation Considering PMU Data

With the increase of power quality and reliability requirements,the distribution management system(DMS)has also developed rapidly.However,due to the errors of the measurement device and the transmission system,resulting in the obtained data of dispatching centre is often incomplete and inaccurate,thus the state estimation of the distribution network need to improve the number and accuracy of data.At present,the estimation of medium and low voltage distribution network is still in the initial stage,can not meet the power system power dispatch needs.With the increasing importance of the distribution network in the power system,the state transition is becoming more and more rapid,and it is in urgent need of a state estimation method which can identify and eliminate the bad data and be quickly at the same time.For the operators to determine the state of the distribution network and according to the state to adjust the operation mode,so that the operation of the grid to achieve the best,to prevent the problems caused by poor grid instability and other issues.In this paper,the current research status and mainstream methods of distribution network state estimation are introduced.The characteristics of existing state estimation methods are analyzed.By introducing the theory based on uncertainty measurement,the indexes of evaluation state estimation results are presented.Based on the idea of uncertainty measurement,a whole PMU advanced state estimation method is proposed.Then the full PMU state estimation is analyzed.The whole PMU state estimation model of the linear measurement equation and the nonlinear measurement equation is introduced,and the model is improved to obtain the algorithm.Secondly,the algorithm of state estimation is analyzed,and the comprehensive optimal solution is obtained by two-stage state estimation.This paper describes the online data sharing technology,which serves the online application service,not only the access side of each system,but also provides a consistent access interface to provide standardized data for other applications.This paper introduces the online data sharing technology and the role of the technology in the evaluation of distribution network status,and introduces the development of the software package.Finally,a simulation test was conducted.Comparison of the distribution network state estimation system for the State Grid Shandong Electric Power Company Weifang power supply company control center is currently applied system.The of IEEE 118 node standard system and real-time data of city power supply company system were tested respectively.After testing and comparison analysis,the new method has high accuracy,high qualified rate,bad data identification ability and good robustness.It plays an important role in improving the safety and stability of distribution network operation,and reduce the daily maintenance workload of the operator.As the distribution network analysis and calculation of the work to be used to the results of state estimation,and distribution network state estimation is currently in its infancy,so the method has a very broad application prospects.