The numerous advantages identified on Modular Multilevel Converter (MMC) type Voltage-Sourced Converter (VSC) have attracted researchers and industrial engineers to consider it for future HVDC implementations. During the design phase of HVDC projects, lots of simulation studies are conducted
using Electromagnetic Transient (EMT) simulation tools. In particular, real-time simulators that combine EMT simulation technique with parallel processing not only offer the speed of simulation enabling large number of simulations to be done at the design stage but also allow the real-time hardware in the loop
testing of designed controllers. This paper presents a detailed model of a point-to-point MMC-VSC system on the Real-Time Digital Simulator (RTDS), suitable for real-time and off-line simulation studies. This paper discusses typical behaviors of an MMC-VSC system simulated for disturbances such as power
order change, power reversal, AC system change, and AC faults. The paper also discusses transient responses such as oscillations after a disturbance. The oscillations associated with the MMCVSC system are investigated using small-signal stability analysis technique and the contributions of physical systems and controllers to oscillations are identified.
S. Arunprasanth, U.D. Annakkage, C. Karawita, and R. Kuffel, International Conference on Power System Transients (IPST), Cavtat, Croatia, Jun. 2015.
KEYWORDS: Modular multilevel converter, real-time digital simulator, electro-magnetic transient, AC system strength, small signal stability