Modeling and Control of an HVDC-VSC Transmission System

A voltage source converter based HVDC (HVDC-VSC) transmission system is considered in this paper. This technology is one of the most promising FACTS in future power systems. A 7-th order non-linear averaged model is chosen for the HVDC-VSC, suitable for transient stability analysis and control design. Its behavior is validated against a more realistic EMTDC-PSCAD model in an open-loop test. After that, an L_gV controller is developed based on the model obtained. The controller is applied to the EMTDC model and its capability to track set-points related with active power, reactive power and other suitable variables is tested. The performance of the proposed controller shows better results than PI controllers proposed in earlier papers, having better stability margin and shorter time response