Document Type : Research Article
Faculty of Electrical Engineering, Shahid Beheshti University, Tehran, Iran
In wide area measurement systems, PMUs are the main component measuring real time synchronized data from different buses. Installation of PMUs at all buses is a primary way to provide full observability of the power network. However, it is not practical in real networks due to the relatively expensive cost of PMUs and other technical limitations. Optimal PMU Placement (OPP) is an optimization problem providing full observability of the power network with minimum number of PMUs. However, additional goals are often considered in OPP problem. In this paper, OPP problem is solved from voltage stability viewpoints. The presence of VSC-HVDC based resources and decomposition of the power network into intentional islanded parts are selected as two main approaches to improve the voltage stability margin in the power network. Hence, OPP solution is obtained considering both integrated and islanded operation modes of the network with the presence of HVDC links and their voltage stability considerations. Since, the location of HVDC could simultaneously affect on the network voltage stability and OPP results, the proposed algorithm is designed as a multi stage method to obtain optimal locations for both HVDC link and PMUs. Due to the linear and binary structure of the problem, Binary Integer Linear Programming (BILP) is used to solve the problem. The performance of the proposed OPP problem is investigated on IEEE 14-, 30- and 118-bus test systems considering normal operation and different contingencies consist of Single PMU Failure (SPF) and Single Line Outage (SLO).