STATCOM and generator excitation: coordinated and optimal control for improving dynamic performance and transfer capability of interconnected power systems

This paper proposes an approach to designing coordinated and optimal control of STATCOM, one of most outstanding FACTS controllers, and generation excitation, a hackneyed while effective control measure, with the objective of improving dynamic performance and transfer capability of interconnected power systems. The approach deliberately considers various important factors: dynamical model of STATCOM. interconnected multiple synchronous machines, structural constraint of existing excitation controllers, decentralized control based on local measurement. Therefore decentralized optimal controllers of STATCOM and generator excitation are simultaneously tuned based on the overall mathematic model and the coordinated LQ control principle and algorithm. Case study is fulfilled with a two-area four-machine power system with STATCOM connected to the inter-area transmission. Digital simulation results verify the effectiveness of the proposed control scheme in improving system transient stability, especially in damping inter-area power oscillation, and in enhancing transfer capability along long-distance tie lines.