Energy Function-Based Model Predictive Control With UPFCs for Relieving Power System Dynamic Current Violation

This paper suggests a novel dynamic protection/control scheme with unified power flow controller (UPFC) to prevent transmission system overload. A transient energy function (TEF)-based model predictive control (MPC) methodology is developed to reduce control cost and enhance power grid resilience. First, a TEF and an associated cost function of UPFCs are constructed based on ac dynamic model with transmission over-current tripping model. Then the derived control constraint for MPC exploits the non-positive time derivative of the TEF with the accommodated admittance, which are optimally regulated by UPFC inputs, to mitigate dynamic current violation based on sensitivity analysis. With the proposed control method, the system can be driven to a stable state without current violation even if part of the UPFCs fails. Finally, the simulation results of 14 bus test case and 118 bus test case demonstrate the effectiveness of our proposed method, as well as the advantage over conventional MPC method.