The research of the control strategies for 4-terminal VSC-HVDC system based on multi point voltage control and their implement

This paper presents the droop control strategies for 4-terminal MMC VSC-HVDC system based on multi point voltage control, which make it possible the automatic coordination among t he converter stations in the VSC-MTDC system independence of the interstation communication. Moreover, the 4-terminal MMC VSC-HVDC system control equipments, upon which the droop control strategies are realized, are designed and implemented. The 4-terminal MMC VSC-HVDC real-time simulation and testing platform, which is mainly the closed-loop connection between the MMC control equipments and RTDS, is also set up in this paper. The simulation and testing results based on the platform prove the validity and accuracy of the droop control strategies for 4-terminal MMC VSC-HVDC system based on multi point voltage control which are presented in this paper.