The implementation of phasor measurement units (PMU) can facilitate monitoring and supervision of power systems. An effective PMU placement strategy closely affects operation control and state estimation. In this study, the optimal PMU placement (OPP) problem is explored to determine the optimal locations of PMUs at the minimum cost. The new approach is based on graph theory and the “bus-characteristics” factor to maximize the observability of the system. The “bus-characteristics” factor is defined by the type of element connected to it and voltage stability analyses. The graph flow method is used to generate the incidence matrix. Then, the “bus-characteristics” factor and voltage stability analysis are employed to identify the optimal PMU placement through a Modified Incidence Matrix (MIM). The Modified Incidence Matrix (MIM), derived from the network graph theory concept, helps to formulate rankings using its diagonal elements. The candidate node search technique is used to enumerate the candidate PMU placement priority. The studies of optimal PMU placement for full observability are performed for two cases: a) Without considering the “bus-characteristics” factor; b) taking into account the “bus-characteristics” factor. The proposed approach is illustrated in the case of the IEEE 14 bus system. Applying the suggested procedure, the number of installed PMUs that fully observed the IEEE 14 bus system was about 21% of the total buses. Besides, the suggested procedure is also suitable for determining the order for planning the PMU expansion. The procedure is suggested to be implemented in case of the 220/400kV Albanian power system.
Karapici et al. (Thu,) studied this question.