Phasor measurement unit placement based on incomplete observability

We present a method for placing phasor measurement units (PMUs) in a power system based on incomplete observability. It makes use of spanning trees of the power system graph and a tree search technique to find the optimal location of PMUs. The novel concept of depth of unobservability is introduced and its impact on the number of PMU placements is explained. Simulated Annealing is used to solve the placement problem constrained by limited communication facilities. We also utilized simulated annealing to solve the pragmatic PMU phased installation problem and to locate new communication sites. We tested the method on study regions of two electric utilities as well as the IEEE systems. The method is a convenient tool for systematic installation of PMUs around the network, in phases if required, to increase observability. The phased installation of PMUs serves to cushion the cost impact of these devices.