Abstract
This paper presents a detailed computer model of a voltage-source converter (VSC) transmission system supplying power to a passive ac network. This model represents all main components of the VSC transmission scheme including the switching converter, ac filters, converter transformer and control circuits. Direct and vector controls are implemented in order to control the degrees of freedom offered by the VSC transmission system. Optimization of the designed control systems is developed in order to improve the overall dynamic performance of the system. Simulation and optimization results are obtained using an electromagnetic simulation program (PSCAD/EMTDC).