Design of Multi-objective Robust HVDC Supplementary Controller Based on Global Signal

HVDC and FACTS devices have been widely applied in power systems for their excellent and flexible control abilities. Their contributions to the damping of system oscillations are of great importance for achieving satisfactory system performance. This paper demonstrates a multi-objective robust damping control design for interarea mode damping in the power system using global stabilizing signals. Global signals have greater observability and controllability compared with the local ones, and in this paper eigenvalue analysis method is adopted to choose the most suitable one. The power system is a very nonlinear system, so the H_infin method of the robust control is used to design the controller. The damping of the system is satisfied by additional constraints on the closed-loop pole location. Both the robust index constraint and the pole location constraint combine a multi-objective problem, and they are transferred into linear matrix inequalities and solved by Matlab toolbox. The method of the controller design is applied to a four-machine two-area system, both the eigenvalue analysis result and the nonlinear time domain simulations conform the effectiveness of the method