Minimum Phasor measurement unit placement for partial observability of power system

This paper presents partial observability techniques for calculating the minimum number of Phasor measurement units (PMUs) required in a power system. The concept of unobservability and various aspects of its effect on the number of PMUs placement are introduced and explained respectively. We formulate the PMU placement problem at a subset of system buses to accomplish different objectives. Furthermore, a MAXOBSERVE problem is introduced to determine the maximum number of observed buses considered at each set of PMUs. We then proof that the minimum number of PMUs placement in a power system based on partial observability require 1/4 of the buses, which provide a more economical solution to system observability compared to the number required for complete observability.