Lossy DCOPF for optimizing congested grids with renewable energy and storage

This paper proposes a DC optimal power flow (DCOPF) with losses formulation for optimizing the allocation and operation of energy storage systems (ESSs) in renewable energy integrated power grids with transmission constraints. This so-called lossy DCOPF (ℓ-DCOPF) represents an effort to bridge the gap between the full OPF, which accurately represents the complete physics of the system but suffers from computational complexity due to nonconvexities, and its widely used linear approximation, the DCOPF, which assumes a lossless network. In this work, we demonstrate that the ℓ-DCOPF provides more accurate results for the proposed ESS optimization problem than the DCOPF. Comparisons of the DCOPF, ℓ-DCOPF, and OPF are made for a 14-bus power system with 15% wind penetration, ramp rates on conventional generation, and network congestion.