Authors : P.K. Dash, R.K. Mallick and A.K. Moharana
Abstract: In this study, a Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) transmission link is considered for the development of a multivariable robust controller to stabilize the AC-VSC-HVDC power system. To maintain the dc voltage and control the active and reactive power at the converter and inverter stations simultaneously a robust H∞ control design methodology is adopted here. For designing the controller output feedback quantities like the converter side dc voltage and reactive power and the inverter side active and reactive power are obtained and used to satisfy an and H∞ norm of the closed loop transfer function matrix. The proposed controller is evaluated for different power system operating conditions like the three-phase short-circuits on the converter and inverter buses, short-circuit on the dc line, loading changes, etc. and its performance show better results than the earlier used PI controllers in respect of the reduction of overshoots, faster settling times and improved damping for the electromechanical oscillations of the generators.
P.K. Dash, R.K. Mallick and A.K. Moharana, 2010. Design of a Robust Multivariable Controller for an AC-VSC-HVDC System. International Journal of Electrical and Power Engineering, 4: 182-192.