Spatial Decomposition Approach to Speed-Up the Security Constrained Unit Commitment

To meet the increasing number of decentralised grids and the rising share of renewable energy sources, speeding up the Security Constrained Unit Commitment (SCUC) is significant for ensuring grid security and affordable power systems. This work conducts a broad background study on the existing methods of SCUC and proposes a novel strategy to speed up it by spatial decomposition approach. The grid decomposition is performed using METIS, a multilevel algorithm for graph partitioning. The decomposed zones are coordinated in a distributed manner by the Alternating Direction Method Of Multipliers (ADMM). The speed-up and optimality of the decomposed method are validated by testing on the IEEE 118 bus system, RTE 6468 bus system and PEGASE 13659 bus systems. The developed SCUC model also includes grid-connected Battery Energy Storage Systems (BESS). The results have proven superior to the centralised methods for bigger grids in terms of speed-up with reduced optimality. This study was successful in finding a relationship between decomposed zones (tie-lines) with the optimality gap and speed-up.