Browsing by Subject "Electric ships"

Now showing 1 - 2 of 2

Designing shipboard electrical distribution systems for optimal reliability
(2013-12) Stevens, McKay Benjamin; Santoso, Surya
Analysis was performed to quantify and compare the reliability of several different notional shipboard DC distribution system topologies in serving their equipment loads. Further, the relationship between the relative placement of loads and generators within a distribution system and the system’s reliability was investigated, resulting in an algorithmically-derived optimal placement configuration in the system topology found to be the most reliable in the initial analysis. Using Markov models and fault-tree analysis, system reliability indices were derived from distribution system component reliability indices, and these values were compared between competing topologies and equipment configurations. A distribution system based on the breaker-and-a-half topology often used in terrestrial utility substations was found to be superior in terms of reliability to the currently-standard ring bus topology. Expected rates of service interruptions to equipment systems served by the breaker-and-a-half system were reduced overall, in some cases dropping dramatically to less than one expected interruption per 10,000 years. This improvement, however, came at the expense of requiring more circuit breakers in the distribution system’s construction. Within this breaker-and-a-half distribution system, an optimal placement of loads and generators was algorithmically derived, which further improved the reliability of the system. This improvement over the base case was marginal, but the optimized placement configuration was able to reduce the expected interruption rate of the ship’s radar system by over 40%.
Modeling and Simulation of Electric Ships’ Power System Components and Their Interaction
(Society for Computer Simulation International, 2007) Ouroua, A.; Jackson, J.R.; Beno, J.H.; Thompson, R.C.; Schroeder, E.
Models of propulsion motors, generators, gas turbines, and power converters are used to determine weights and volumes, evaluate designs, and predict performance of power system components for all-electric navy ships. The finite element analysis method using 3D CAD models is used to validate designs and predict performance under prescribed constraints that simulate realistic operational conditions. These models and analyses allow the development of complete, high-fidelity, design-based specifications of power system components before prototypes are built and tested. Examples of electromagnetic, mechanical, structural, thermal, shock and vibration analyses of models representing integrated designs of electric machines are presented. Modeling and simulation at system level play an equally crucial role in system architecture design. Simulation examples using a power system model for an all-electric ship are presented.