A novel hybrid multi-terminal HVDC (MTDC) system, composed of line commutated thyristor current source converters (CSC) and GTO voltage source converters ( VSC) , is proposed for the extension of the conventional HVDC system. To verify the feasibility of the proposed system, a simulation model for the hybrid three-terminal HVDC system is developed, which consists of a VSC terminal, a CSC rectifier, and a CSC inverter. Based on the developed MTDC system, two control schemes are proposed. The performance of t...