Stability of Disturbance Based Unified Control

Introduction of renewable generation leads to significant reduction of inertia in power system, which deteriorates the quality of frequency control. This paper suggests a new control scheme utilizing controllable load to deal with low inertia systems. Optimization problem is formulated to minimize the systems deviations from the last economically optimal operating point. The proposed scheme combines frequency control with congestion management and maintaining inter-area flows. The proposed distributed control scheme requires only local measurements and communication with neighbors or between buses participating in inter-area flows. Global asymptotic stability is proved for arbitrary network. Numerical simulations confirm that proposed algorithm can rebalance power and perform congestion management after disturbance with transient performance significantly improved in comparison with the traditional control scheme.