A coordinated control approach for FACTS and generator excitation system

A robust control approach is proposed in the paper for the coordinated control of geographically distributed FACTS devices and generator excitation systems to improve the dynamic stability of power systems. First, a nonlinear feedback law is found which linearizes the system model. Then, the interaction between FACTS and excitation system is treated as parameter uncertainty and solved by robust control theory. The proposed coordinated controller is designed based on local measurements. An example power system with the installation of TCSC is employed to explore the effectiveness of the proposed approach. The control objective is to achieve both voltage regulation and system stability enhancement. Real-time simulation is carried out by means of RTDS (Real Time Digital Simulator) to get more practical results. Simulation results show that both voltage regulation and transient stability enhancement can be achieved regardless of the system operating point, and compared to other kinds of controllers, the proposed controller gives better dynamic performance and robustness.