Scenario-based stability-assessment of converter-fed DC-ship grids loaded with pulsed power

For future all-electric ships, one possibility is a DC grid fed by converter-controlled generators and loaded by converter-controlled components. The consumers can be categorized by their power demand - mainly constant or pulsed operation. Especially pulsed power is a major challenge in the scope of grid stability and, therefore, has to be analyzed and assessed in the early conceptual-design phase. So far, many studies are based on strongly simplified models. Either all the power-electronic converters are substituted by only one or two converters or they are represented by sources with certain impedances. Due to the low available short-circuit power, these simplifications are not valid - the influence of the time-variant characteristics of power-electronic converters must not be neglected. In this paper, a scenario-based approach for the grid-stability assessment is presented which can handle very complex converter-containing ship grids and is valid for pulsed-load investigations.