Optimal Control Design for VSC-HVDC Systems

This paper deals with modeling and optimal control design of VSC-HVDC transmission system in order to enhance system stability. The steady of the state mathematical model for GL (Generator-Load) VSC-HVDC system is developed and the decoupled relationship between the controlling variables is proposed. Furthermore, this work focuses on the design of optimal PI (proportional-integral) controller which aims to maintain DC link voltage and control the reactive power. The effectiveness of the proposed optimal control scheme is proved through digital simulation studies on a VSC-HVDC power system, using MATLAB/Simulink software. The simulation results shows that the proposed optimal PI controller is effective to enhance power system stability.