A two-phase investment model for optimal allocation of phasor measurement units considering transmission switching

• We propose a two-phase investment decision model for the optimal placement of PMUs.
• We show the advantages of the two-phase PMU placement plan.
• We formulate the PMU placement problem as an integer linear programming problem.
• We consider the N − 1 observability reliability requirement in our proposed model.
• We study the impact of transmission switching on the optimal placement of PMUs and incorporate it into our ILP model.

Ensuring the reliability of an electrical power system requires a wide-area monitoring and full observability of the state variables. Phasor measurement units (PMUs) collect in real time synchronized phasors of voltages and currents which are used for the observability of the power grid. Due to the considerable cost of installing PMUs, it is not possible to equip all buses with PMUs. In this paper, we propose an integer linear programming model to determine the optimal PMU placement plan in two investment phases. In the first phase, PMUs are installed to achieve full observability of the power grid whereas additional PMUs are installed in the second phase to guarantee the N − 1 observability of the power grid. The proposed model also accounts for transmission switching and single contingencies such as failure of a PMU or a transmission line. Results are provided on several IEEE test systems which show that our proposed approach is a promising enhancement to the methods available for the optimal placement of PMUs.