Optimal Placement Of PMU In Power Network Considering Requirement Of Static Voltage Stability Analysis

As gradual completion of China’s UHV network building, the linkages between regional power grids are more and more close. The expansion of power system and steady growth of load worsen the situation of voltage stability. PMU can collect voltage phasors of bus and current phasors of associated branches real-timely in WAMS, and synchronize them to a uniform time scale, which provide new ideas and methods for condition monitoring and voltage stability analysis of power system. Currently, PMU devices are relatively expensive and mainly installed in transmission network. Most research concentrated on minimizing the installation number of PMU subjected to the requirements of observability.Firstly, this paper overviews the issue of voltage stability and introduces problem of optimal placement of PMU (OPP), followed by elaborating the principle of system observability and introducing several algorithms of OPP, as well as several application areas of PMU. Taking into account of the cost of network architecture and communication lines installation, this paper proposes a minimum spanning tree algorithm which could be used in the placement of PMU from the point of view of graph theory. By using Kruskal algorithm to solve the problem of minimum spanning tree, the proposed method can quickly resolve OPP problems in engineering applications economically.PMU can and should provide help for voltage stability analysis. After introduction method of voltage stability analysis and several representative indices, this paper qualitative analyzes the impact on voltage stability analysis by adopting PMU measurement data, On this basis, the paper then discusses the obtain of Thevenin equivalent parameters and the identification of load static voltage model. A static voltage stability index based on PMU measurement data is put forward accordingly and verified in standard test system.After considering the problems of OPP and voltage stability, this paper applies the proposed index to guide the OPP. Calculate bus index firstly, then configure PMU by bus type, and observability verification in the end. Example results on IEEE standard system and real grid show that proposed index and OPP method are adaptive and effective. Aiming at the problem of OPP under the condition of N-1, this paper also presents a placement method based on key fault line selection. Also, example analysis is demonstrated to verify the proposed method.