Potential and Efficient Computation of Corrective Power Flow Control in Cost vs. Risk Trade-Off

Increased levels of variable renewable generation lead to increased variations in power flows. If the required transmission capacity is provided by a grid with no or little controllability as in today´s power system, the consequence is a significant under-utilization of the transmission assets most of the time. In this paper, corrective power flow control is used to improve the utilization of the existing transmission capabilities and adjust the grid to the varying needs of generation and demand. In lieu of the traditional N-1 security formulation, a risk based approach is employed. The resulting risk constrained economic dispatch is solved efficiently by decomposing it into a two stage process by using newly defined locational security impact factors (LSIF). In addition, these LSIFs provide information on the most effective, location-dependent measures to reduce system risk. Simulations provide insights into the effectiveness of the proposed approach and the potential of corrective power flow control to reduce cost of dispatched generation and to decrease system risk.