A study on monitoring technology for multi-terminal ±500kV VSC-HVDC power transmission system

State Grid of China plans to put a ± 500kV/3000MW four-terminal voltage source converter based high voltage direct current (VSC-HVDC) transmission system into operation by 2020. In compare to existing VSC-HVDC transmission systems, this system has higher voltage level and transmission capacity. Accordingly, grid devices and topology would be significantly different. This paper introduces configuration of the transmission system, and proposes a monitoring design scheme based on existing monitoring functions of Smart Grid Dispatching and Control System (SGDCS). Theoretical analysis shows that, the detail monitoring functions given from aspects of grid modelling, data acquisition, topology analysis and intelligent alarming would be helpful for the reconstruction of existing SGDCS system.