Dynamic Simulation of Shipboard Electric Power Systems

Abstract : It is the aim of the proposed research to develop digital computer simulation models for a typical shipboard electric propulsion system, conduct dynamic analyses and determine viable control schemes for such a system. Electric propulsion for shipboard use is being considered as an attractive alternative to the geared diesel and gas turbine mechanical drives currently being used in most naval ships. Prior to building an electric propulsion drive system, the dynamic behavior must be understood and methods for controlling the system have to be determined. A shipboard electrical system is small in size and has fewer components than a typical commercial power distribution system. A typical combatant ship may have three or four generators with a combined capacity of 80-100 megawatts. Most of this capacity is used by the propulsion motors, which for a two shaft ship will be rated in the range of 35-40 megawatts each. These loads, which are large with respect to the generating capacity, make the analysis of shipboard electrical systems more difficult than typical commercial power systems. Many of the simplifying assumptions used in the analysis of commercial power systems are not valid with shipboard systems. This complication requires a detailed model of the entire system including the relevant dynamic of each component.