Development of a Dynamic Performance Management Framework for Naval Ship Power System using Model-Based Predictive Control

Medium-Voltage Direct-Current (MVDC) power system has been considered as the trending technology for future All-Electric Ships (AES) to produce, convert and distribute electrical power. With the wide employment of highrequency power electronics converters and motor drives in DC system, accurate and fast assessment of system dynamic behaviors , as well as the optimization of system transient performance have become serious concerns for system-level studies, high-level control designs and power management algorithm development. The proposed technique presents a coordinated and automated approach to determine the system adjustment strategy for naval power systems to improve the transient performance and prevent potential instability following a system contingency. In contrast with the conventional design schemes that heavily rely on the human operators and pre-specified rules/set points, we focus on the development of the capability to automatically and efficiently detect and react to system state changes following disturbances and or damages by incooperating different system components to formulate an overall system-level solution. To achieve this objective, we propose a generic model-based predictive management framework that can be applied to a variety of Shipboard Power System (SPS) applications to meet the stringent performance requirements under different operating conditions. The proposed technique is proven to effectively prevent the system from instability caused by known and unknown disturbances with little or none human intervention under a variety of operation conditions. The management framework proposed in this dissertation is designed based on the concept of Model Predictive Control (MPC) techniques. A numerical approximation of the actual system is used to predict future system behaviors based on the current states and the candidate control input sequences. Based on the predictions the optimal control solution is chosen and applied as the current control input. The effectiveness and efficiency of the proposed framework can be evaluated conveniently based on a series of performance criteria such as fitness, robustness and computational overhead. An automatic system modeling, analysis and synthesis software environment is also introduced in this dissertation to facilitate the rapid implementation of the proposed performance management framework according to various testing scenarios

Multiagent autonomous energy management

The objective of this thesis is to design distributed software agents for reliable operation of integrated electric power systems of modern electric warships. The automatic reconfiguration of electric shipboard power systems is an important step toward improved fight-through and self-healing capabilities of naval warships. The improvements are conceptualized by redesigning the electric power system and its controls. This research focuses on a new scheme for an energy management system in the form of distributed control/software agents. Multiagent systems provide an ideal level of abstraction for modeling complex applications where distributed and heterogeneous entities need to cooperate to achieve a common goal. The agents\u27 task is to ensure supply of the various load demands while taking into consideration system constraints and load and supply path priorities. A self-stabilizing maximum flow algorithm is investigated to allow implementation of the agents\u27 strategies and find a global solution by only considering local information and a minimum amount of communication. (Abstract shortened by UMI.)

Design for Support in the Initial Design of Naval Combatants

The decline of defence budgets coupled with the escalation of warship procurement costs have significantly contributed to fleet downsizing in most major western navies despite little reduction in overall commitments, resulting in extra capability and reliability required per ship. Moreover, the tendency of governments to focus on short-term strategies and expenditure has meant that those aspects of naval ship design that may be difficult to quantify, such as supportability, are often treated as secondary issues and allocated insufficient attention in Early Stage Design. To tackle this, innovation in both the design process and the development of individual ship designs is necessary, especially at the crucial early design stages. Novelty can be achieved thanks to major developments in computer technology and in adopting an architecturally-orientated approach to early stage ship design. The existing technical solutions aimed at addressing supportability largely depend on highly detailed ship design information, thus fail to enable rational supportability assessments in the Concept Phase. This research therefore aimed at addressing the lack of a quantitative supportability evaluation approach applicable to early stage naval ship design. Utilising Decision Analysis, Effectiveness Analysis, and Analytic Hierarchy Process, the proposed approach tackled the difficulty of quantifying certain aspects of supportability in initial ship design and provided a framework to address the issue of inconsistent and often conflicting preferences of decision makers. Since the ship’s supportability is considered to be significantly affected by its configuration, the proposed approach utilised the advantages of an architecturally-orientated early stage ship design approach and a new concept design tool developed at University College London. The new tool was used to develop concept level designs of a frigate-sized combatant and a number of variations of it, namely configurational rearrangement with enhancement of certain supportably features, and an alternative ship design style. The design cases were then used to demonstrate the proposed evaluation approach. The overall aim of proposing a quantitative supportability evaluation approach applicable to concept naval ship design was achieved, although several issues and limitations emerged during both the development as well as the implementation of the approach. Through identification of the research limitations, areas for future work aimed at improving the proposal have been proposed

Smart Manufacturing

This book is a collection of 11 articles that are published in the corresponding Machines Special Issue “Smart Manufacturing”. It represents the quality, breadth and depth of the most updated study in smart manufacturing (SM); in particular, digital technologies are deployed to enhance system smartness by (1) empowering physical resources in production, (2) utilizing virtual and dynamic assets over the Internet to expand system capabilities, (3) supporting data-driven decision-making activities at various domains and levels of businesses, or (4) reconfiguring systems to adapt to changes and uncertainties. System smartness can be evaluated by one or a combination of performance metrics such as degree of automation, cost-effectiveness, leanness, robustness, flexibility, adaptability, sustainability, and resilience. This book features, firstly, the concepts digital triad (DT-II) and Internet of digital triad things (IoDTT), proposed to deal with the complexity, dynamics, and scalability of complex systems simultaneously. This book also features a comprehensive survey of the applications of digital technologies in space instruments; a systematic literature search method is used to investigate the impact of product design and innovation on the development of space instruments. In addition, the survey provides important information and critical considerations for using cutting edge digital technologies in designing and manufacturing space instruments

Department of Computer Science Activity 1998-2004

This report summarizes much of the research and teaching activity of the Department of Computer Science at Dartmouth College between late 1998 and late 2004. The material for this report was collected as part of the final report for NSF Institutional Infrastructure award EIA-9802068, which funded equipment and technical staff during that six-year period. This equipment and staff supported essentially all of the department\u27s research activity during that period

A Bibliography of NPS Space Systems Related Student Research, 2013-2022

Dudley Knox Library, Naval Postgraduate School.Approved for Public Release; distribution is unlimite