Interactions Between Bandwidth Limited CPLs and MMC Based MVDC Supply

With the improvement in the power electronic technologies, medium voltage dc (MVDC) electrical distribution systems are being considered for on-shore and off-shore applications. These future MVDC electrical distribution systems are expected to provide the possibility of easy interfacing of the renewable energy sources, improving the dynamics of the system and also help in reducing the carbon footprint of energy sources. Modular multilevel converters (MMCs) are used in high voltage dc (HVDC) applications and are being considered for MVDC applications as well. In this paper, we present an MVDC electrical distribution system where the source converter is an MMC and the loads exhibit bandwidth limited constant power load (CPL) behaviour. An analysis is carried out on the dynamic interactions between the MMC source converter and CPLs, considering varying distribution cable lengths between the source and the load, the filtering effort at the load end and different loading conditions