"Kunbei-Liubei-Longmen HVDC Project"

the world’s first UHV three-terminal hybrid HVDC project

will be completed and put into operation in two years. This project is to transmit the large capacity hydropower in Yunnan to Guangxi and Guangdong by adopting advanced DC transmission technology. To study all kinds of fault features of UHV remote overhead DC transmission lines as well as explore a new criterion for better DC protection

the zero-sequence resistance and inductance frequency characteristics of DC transmission lines were analyzed

and the simplified model of grounding electrode line of converter station was proposed.The DC line models of Kunbei-Liubei Line and Liubei-Longmen Line were also designed

and a complete set of dynamic physical model of distributed parameters with grounding pole was established. Tests showed that the model system met the design requirements

which was able to reflect the physical characteristics of prototype system accurately as well as carry out various types of short circuit experiments at different fault points

providing valuable experimental data for the research of DC transmission technology.