Impact of MMC-HVDC Control Parameter Selection on the Dynamic Performance of AC System

High penetration of voltage source converter (VSC) based system is anticipated in future power systems. This study discusses the interaction of modular multilevel converter (MMC) based high voltage dc (HVDC) system with the dynamic of the host ac network in the electromechanical time frame. The respective controls for MMC-HVDC system suitable for the stability studies in the electromechanical time-frame are considered. This paper gives insight into the effects of several important sensitivities such as (i) MMC control implementation, (ii) non linearity associated with the fault ride through implementation, and (iii) phase locked loop parameters on ac system dynamics. The comprehensive analysis has been performed using an equivalent model of Great British transmission system.