Robust damping control of power system with TCSC using a multi-model system approach

The purpose of this paper is to present the design approach of a robust damping controller of thyristor-controlled series compensator (TCSC) for systems with multiple operating points. The design objective is to find a common output feedback controller for TCSC which could increase system damping of power system oscillations under different system operating points. The robust damping control problem for systems with multiple operating points is initially considered as a regional pole placement problem for a multi-model system which could be represented by as set of nonlinear matrix inequalities (NMI). Then, a two-step linear matrix inequality (LMI) method is introduced to solve the NMI problem so that the unknown variables of our output feedback controller can be determined. In the end, the obtained controller is verified by nonlinear simulations on real-time digital simulator (RTDS).