Publications
Evaluating the effects of real power losses in optimal power flow-based storage integration
This paper proposes a dc optimal power flow (DCOPF) with losses formulation (the ℓ-DCOPF + S problem) and uses it to investigate the role of real power losses in OPF-based grid-scale storage integration. We derive the ℓ-DCOPF + S problem by augmenting a standard DCOPF with storage (DCOPF + S) model to include quadratic real power loss approximations. This procedure leads to a multiperiod nonconvex quadratically constrained quadratic program, which we prove can be solved to optimality using either a semidefinite or second-order cone relaxation. Our approach has some important benefits over existing models. It is more computationally tractable than ACOPF with storage (ACOPF + S) formulations and the provably exact convex relaxations guarantee that an optimal solution can be attained for a feasible problem. Adding loss approximations to a DCOPF + S model also leads to a more accurate representation of locational marginal prices, which have been shown to be critical in determining optimal storage dispatch and siting in prior ACOPF + S-based studies. Case studies demonstrate the improved accuracy of the ℓ-DCOPF + S model over a DCOPF + S model and the computational advantages over an ACOPF + S formulation.