Coordinated control of SSO via MMC_SSDC and SEDC
WANG Zhongyang, LI Runqiu, ZHU Anming, LUO Di
(State Grid Shanxi Economic Research Institute, xian 710065, China)
 

Abstract: Aiming at the subsynchronous oscillation (SSO) of hybrid ACDC transmission system which contained modular multilevel converter based High Voltage Direct Current (MMC_HVDC), the coordinated control of subsynchronous oscillation damping controller (MMC_SSDC) and supplementary excitation damping controller (SEDC) was researched. Firstly, aiming at the hybrid system, the structure and parameters of MMC_SSDC and SEDC were designed. Then, the practicability of the coordinated control of SSO via MMC_SSDC and SEDC was studied in both theory and electrical damping characteristics. Finally, the simulation model with 335 levels was built on PSCAD/EMTDC, and the results validated the correctness of the conclusion and the efficiency of the coordinated control strategy. The results indicate that MMC_SSDC and SEDC can superpose each other on increasing the electrical damping characteristic of whole system, and the coordinated control strategy proposed in this paper is practicable.
Key words: modular multilevel converter(MMC) based high voltage direct current (HVDC); subsynchronous oscillation; subsynchronous oscillation damping controller; supplementary excitation damping controller; coordinated control strategy