Simulation study of the Zhoushan project as a three-terminal DC transmission system

This paper presents a simulation study of the proposed three-terminal DC transmission system in Zhoushan Archipelago located in East China Sea. In this paper, two kinds of topologies of converter are compared to select the suitable one and the DC voltage level is determined. Then, station controller based on direct current control strategy is designed. A multipoint DC voltage control strategy based on DC voltage error method is proposed to improve reliability of the system. An additional frequency control strategy is put forward to make it possible for VSC-HVDC system to take part in the frequency control. Finally, the three-terminal DC transmission system model is developed in PSCAD/EMTDC. In Results from the simulation study show that the three-terminal DC Transmission system based on modular multilevel converter (MMC) is technically feasible for Zhoushan project.