Measurement-based Optimal Power Flow with Linear Power-flow Constraint for DER Dispatch

This paper proposes a measurement-based method to obtain optimal power-flow (OPF) solutions that optimize distribution-system operations by dispatching active- and reactive-power outputs of distributed energy resources (DERs). Central to the proposed method is the estimation of a linear power-flow model from synchronized voltage and power-injection data collected from distribution-level phasor measurement units (D-PMUs). The estimated model is then incorporated into an OPF problem as an equality constraint. We formulate a quadratic cost function that enables co-optimization of DER active- and reactive-power costs, voltage deviations away from prescribed reference levels, as well as active- and reactive-power deviations from desired setpoints. Via numerical simulations of the IEEE 33-bus distribution test system, we demonstrate that the proposed measurement-based method yields sufficiently accurate solutions compared to model-based OPF solutions. Furthermore, we highlight the adaptability of the proposed method in case an accurate network model is not available.