Voltage Stability-Constrained Optimal Simultaneous Placement of PMUs and Channels Enhancing Measurement Reliability and Redundancy

In this paper, a channel-oriented method is proposed for optimal placement of phasor measurement units (PMUs) with the objective function of explicit cost of PMUs and their channels. PMU measurement channels are treated as optimization binary variables, and a PMU installed at a bus assigns channels to observe its adjacent buses only if it is economically justified. Since power system substations have different reliability levels, in order to enhance reliability of the measurement system, PMUs and their channels are encouraged to be employed at more reliable buses and branches. In addition, in order to monitor fragile areas of power systems for prevention of voltage collapse, PMUs and their channels are assigned to observe buses with vulnerable voltage stability status. Furthermore, in order for a more economical and practical solution, the most probable contingencies are identified using the Monte Carlo simulation to be incorporated in the problem. Also, PMU failures and branch outages are modeled with a technique resulting in a less cost than existing methods. Channel failure is also modeled as a new type of contingency. The efficiency of the proposed method is evaluated by testing it on standard and practical large-scale test systems.