Linear /Quadratic Programming Based Optimal Power Flow using Linear Power Flow and Absolute Loss Approximations

This paper presents a novel method to approximate the nonlinear AC optimal power flow (OPF) into tractable linear/ quadratic programming (LP/QP) based OPF problems that can be used for power system planning and operation. We derive a linear power flow approximation and include a convex reformulation of the power losses in the form of absolute value functions. We show three ways how we can incorporate this approximation into an LP/QP based OPF problem. The usefulness of our OPF methods is analyzed for the IEEE test case grids. As a result, the errors on voltage magnitudes and angles are reasonable, while obtaining near-optimal results. We find that our methods reduce significantly the computational complexity compared to the nonlinear AC-OPF making them a good choice for planning purposes.