A Hybrid Transmission Grid Architecture Enabling Efficient Optimal Power Flow

Abstract

The recent rise of electricity generation based on renewable energy sources increases the demand for transmission capacity. Capacity expansion via the upgrade of transmission line capacity, e.g., by conversion to a high-voltage direct current (HVDC) line, is an attractive option. In this paper, it is shown that if the upgrade to HVDC is applied systematically to selected transmission lines across the grid, a hybrid architecture is obtained that enables an efficient and globally optimal solution of the optimal power flow (OPF) problem. More precisely, for conventional meshed AC transmission grids the OPF problem is nonconvex and in general NP-hard, rendering it hard to solve. We prove that after the upgrade to the proposed hybrid architecture, the same mesh topology facilitates an exact convex relaxation of the OPF problem, enabling its globally optimal solution with efficient polynomial time algorithms. This OPF method is then employed in simulations, which demonstrate that the hybrid architecture can increase the effective transmission capacity and substantially reduce the generation costs, even compared to the AC grid with optimal transmission switching.

IEEE Transactions on Power Systems

References in corpus (2)

• Convex Relaxation of Optimal Power Flow, Part I: Formulations and Equivalence
• Convex Relaxation of Optimal Power Flow, Part II: Exactness

Cited by in corpus (5)

• Two-stage multi-objective OPF for AC/DC grids with VSC-HVDC: Incorporating decisions analysis into optimization process
• Hybrid AC/DC Transmission Expansion Planning Considering HVAC to HVDC Conversion Under Renewable Penetration
• hynet: An Optimal Power Flow Framework for Hybrid AC/DC Power Systems
• The Hybrid Transmission Grid Architecture: Benefits in Nodal Pricing
• Feature- and Structure-Preserving Network Reduction for Large-Scale Transmission Grids