Line Protection Setting and Configuration Scheme for Cascaded Multi Terminal UHVDC Transmission System

In the case of dispersed energy sources and load center, UHVDC (Ultra-high Voltage Direct Current) system in cascaded connection mode is more suitable and efficient. However, it brings up challenges for original control strategy and line protection schemes. In order to coordinate line protection action with new connection mode more appropriately, a novel control strategy has been proposed, and based on which the original line protection scheme used in conventional UHVDC system is analyzed. And referred to parameters of an actual project, a simulation model that UHVDC system connects in receiving end cascaded mode has been constructed in PSCAD/EMTDC. According to simulation exhaustive method used in engineering, the setting, configuration, verification and evaluation of traveling wave protection are carried out. Finally, a reasonable line protection configuration and action scheme is proposed for each line fault.