Static and dynamic behavior studies for UHVDC separation pole connection to AC grid

With the development of UHVDC technology, the capacity of power transmission is getting increasingly bigger, which will generate a great impact on the receiving power system. This paper proposed a novel separating pole connection (SPC) mode to address this issue. Firstly, the paper introduced the configuration concept of SPC and presented the definition of short circuit ratio for separating pole connection mode (SPCSCR). And the abilities of power transmission related with SPCSCRs under different connection modes were analyzed. Secondly, the overall control strategies for UHVDC SPC mode were studied and suggested independent control systems for two poles respectively. Finally, the dynamic behavior of SPC mode was studied by a case of UHVDC transmission using PSCAD/EMTDC, and the results validated the advantages of this structure, which has great superiority in stable operation and flexible power transmission.