A Spatial Decomposition Method for Solving the Security-Constrained Unit Commitment Problem

Today, we are experiencing exponential growth in distributed energy sources and storage systems, such as Battery Energy Storage Systems (BESS), which participate in the day-ahead energy market. Moreover, the need for energy market coupling to ensure social welfare maximization and grid security makes the Security-Constrained Unit Commitment (SCUC) problem more challenging due to the increasing problem size. This work proposes a novel approach for solving the SCUC problem in a distributed manner by decomposing the grid into multiple areas connected by tie-lines. The solution leverages the Alternating Direction Method of Multipliers (ADMM) to solve the problem efficiently. The proposed Spatially Decomposed SCUC method significantly reduces the computational burden arising from the combinatorial nature of the problem. The speed-up and optimality of the proposed method is validated on the IEEE 118-bus and RTE 6468-bus systems.