Dynamic Assessment of Source-Load Interactions in Marine MVDC Distribution

Medium-voltage direct-current (MVDC) distribution is a possible replacement due to the advancements in power electronic technologies, for existing medium-voltage ac distribution on ships. The new systems based on MVDC are expected to increase fuel efficiency, remove bulky low-frequency transformers used for voltage coordination, and integrate storage technologies. These expected benefits of MVDC come with challenges such as stability and reliability of the new distribution system. In this paper, the effect of three different source-side converters, based on commercially available technology, on the MVDC distribution grid and their interactions with the constant power loads (propulsion drives) are investigated. Additionally, the effect of variations in the filtering effort and the distribution lengths on the system stability is analyzed using the impedance-based stability assessment.