TCSC wide-area damping controller to enhance the damping of inter-area oscillation for power systems with considering the time delay of wide-area signals

The aim of this paper is to investigate the design method of robust thyristor controlled series capacitor (TCSC) wide-area damping controller (WADC) to enhance the stability of power system with considering time delay of wide-area signals. Although wide-area measurement system (WMAS) is being widely applied to monitor and control the interconnected power systems, which can enable the use of measured signals from remote locations for centralized control purpose, the impact of time delays introduced by remote signal transmission and processing in WAMS cannot be ignored. So this paper describes the TCSC wide-area damping controller design problem of power system as a public time-delay feedback control problem. Based on the established time-delay power system model, the TCSC wide-area damping controller is proposed by the free-weighting matrices method, which is expressed with a set of linear matrix inequality (LMI) constraints, and the pole placement method. Finally, the simulation results on a two-area four-machine test system are illustrated by comparing with various time delays of wide-area signals. It demonstrates that the designed TCSC damping controller not only inhibits inter-area oscillation evidently, but also is robust to various time delays.