Optimal PMU Allocation on Smart Grids: a MILP Model considering Minimal Current Measurements

Abstract

This paper presents an optimal phasor measurement unit (PMU) allocation strategy. PMUs provide precise measurements of voltage and current phasors of a power system. These measurements can be used for detailed dynamic analysis of the system which would not be possible with standard measurements, but their high cost makes the allocation of resources critical. The current state of the art simply allocates PMUs at certain buses and assumes all possible current measurements are taken. In this work, the problem is formulated as a mixed integer linear programming (MILP) problem that considers which branch current phasors each PMU will measure besides which buses the PMUs will be installed at. This is done in two ways: updating the objective function to include individual current measurement costs and creating a new optimization problem altogether. Updating the objective function is an improvement on cost minimization, but is essentially the same for observability analysis. The new optimization problem allows for a more comprehensive cost minimization and more precise topological observability analysis compared to the methods in literature. For larger systems, this methodology can change which buses should receive PMUs and reduce cost to the point of allowing more PMUs to be used. The method is tested on 7, 14, 57, and 118 bus IEEE systems.