PMUs placement with max-flow min-cut communication constraint in smart grids

Abstract

Synchronized phasor measurement units (PMUs) play an important role in the process of monitoring, controlling, and protection of today's smart grid networks. Therefore, a strategic placement of these PMUs is essential to perform these tasks. Previous studies in this area mostly concentrate on minimizing the total number of PMUs while maintaining the system fully observable in various contingency situations. However, most of them neglect the communication constraints among PMUs, e.g., the finite communication capacity1 available when using power line communications (PLC) among PMUs. In this paper, we introduce two different formulations to solve the problem of optimal PMUs placement (OPP), while taking into consideration a communication constraint for the case where the communication between the PMUs and the control center is established via wired power lines. Therefore, there will be a constraint on the max-flow min-cut in the wired smart grid model. In the first formulation, we find the best location or bus in the grid for the controller to be located in order to support the communication max-flow min-cut constraint. In the second formulation, we fix the controller at a certain bus and find the optimal solution that maintains the networks full observability and also satisfies the communication max-flow min-cut constraint. We also apply our formulations to different IEEE standard bus systems, and our results reveal that there are some buses at which we should avoid placing the controller, and the solution of the conventional OPP problem may not support the max-flow min-cut constraint.