Observability Analysis Of AC/DC Hybrid Power System

After analyzing the DC transmission system and simplifying its model reasonably,this paper draws a conclusion that the necessary and sufficient condition of the observability of the whole DC system is the observability of the DC lines.Considering the redundancy of measure configuration,the results of a series of simulations upon different measure configurations show an universal rule to be applicable in both two-terminal and multi-terminal DC system based on the solvability condition of power flow.And then based on the characteristics of AC/DC hybrid power system,this paper analyzes the impact of embedded DC sub-system and then presents a new concept called the DC-related coefficient of boundary node.Then the alternating iteration method is applied to merge the measurement islands in AC/DC hybrid power system and several rules and steps to judge the combination of measurement islands of AC/DC hybrid power system are presented in this paper.The results of IEEE 14 system show that the rules presented in this paper are valid and correct. Finally,after analysing the results,this paper summarizes the impact of the measurement configuration of AC and DC power system on the extension of the observation area.