The work presented in this thesis was concerned with the implementation of a damage control method for U.S. Navy shipboard power systems (SPS). In recent years, the Navy has been seeking an automated damage control and power system management approach for future reconfigurable shipboard power systems. The methodology should be capable of representing the dynamic performance (differential algebraic description), the steady state performance (algebraic description), and the system reconfiguration routines (discrete events) in one comprehensive tool. The damage control approach should also be able to improve survivability, reliability, and security, as well as reduce manning through the automation of the reconfiguration of the SPS network. To this end, this work implemented a damage control method for a notional Next Generation Integrated Power System. This thesis presents a static implementation of a dynamic formulation of a new damage control method at the DC zonal Integrated Flight Through Power system level. The proposed method used a constrained binary genetic algorithm to find an optimal network configuration. An optimal network configuration is a configuration which restores all of the de-energized loads that are possible to be restored based on the priority of the load without violating the system operating constraints. System operating limits act as constraints in the static damage control implementation. Off-line studies were conducted using an example power system modeled in PSCAD, an electromagnetic time domain transient simulation environment and study tool, to evaluate the effectiveness of the damage control method in restoring the power system. The simulation results for case studies showed that, in approximately 93% of the cases, the proposed damage algorithm was able to find the optimal network configuration that restores the power system network without violating the power system operating constraints.

The United States Navy is committed to developing technology for an All-Electric Ship (AES) that promises to improve the affordability and capability of its next-generation warships. With the addition of power-intensive 21st century electrical systems, future thermal loads are projected to exceed current heat removal capacity. Furthermore, rising fuel costs necessitate a careful approach to total-ship energy management. Accordingly, the aim of this research is to develop computer tools for early-stage design of shipboard energy distribution systems. A system-level model is developed that enables ship designers to assess the effects of thermal and electrical system configurations on fuel efficiency and survivability. System-level optimization and design exploration, based on these energy system models, is challenging because the models are sometimes computationally expensive and characterized by discrete design variables and discontinuous responses. To address this challenge, a classifier-guided sampling (CGS) method is developed that uses a Bayesian classifier to pursue solutions with desirable performance characteristics. The CGS method is tested on a set of example problems and applied to the AES energy system model. Results show that the CGS method significantly improves the rate of convergence towards known global optima, on average, when compared to genetic algorithms. / text

Energy storage systems will likely be needed for future shipboard power systems that supply loads with high power variability such as pulsed power loads. The power generation in shipboard power systems may not be sufficient to satisfy the energy demands of the pulsed power load systems operating in conjunction with other ship service loads. Two fundamental items in evaluating the requirements of an energy storage system are the energy storage capacity and the ratings of the power conversion equipment that interfaces the energy device to the power system. The supply current of pulsed power load systems is aperiodic and cannot be described in terms of active power. Also, the RMS value and thus apparent power are only defined for periodic quantities. Therefore traditional methods of rating power equipment cannot be used. This thesis describes an approach to determine the ratings of an energy storage interface and the energy storage capacity of an energy storage device as a function of load and supply parameters. The results obtained using the proposed approach are validated with the results obtained from the simulation model of the generator supplying a pulsed power load in conjunction with an energy storage system. The energy storage system requirements for various pulsed power load profiles are obtained using the proposed approach. The method used for determining the ratings of an energy storage system utilizes an orthogonal decomposition of pulsed power load system supply current evaluated within a sliding window. The signals obtained from the decomposition are also useful in generating the control reference signals for the energy storage interface. Although the approach and methods are focused on a particular structure of the pulsed power load system, they may be generalized for use in any type of configuration of a pulsed power load system.

Approved for public release, distribution is unlimited / This thesis is part of an ongoing research conducted at the Naval Postgraduate School to achieve the autonomous shipboard landing of Unmanned Aerial Vehicles (UAV). Two main problems are addressed in this thesis. The first is to establish communication between the UAV's ground station and the Autonomous Landing Flight Control Computer effectively. The second addresses the design and implementation of an autonomous landing controller using classical control techniques. Device drivers for the sensors and the communications protocol were developed in ANSI C. The overall system was implemented in a PC104 computer running a real-time operating system developed by The Mathworks, Inc. Computer and hardware in the loop (HIL) simulation, as well as ground test results show the feasibility of the algorithm proposed here. Flight tests are scheduled to be performed in the near future. / Lieutenant Junior Grade, Mexican Navy

Approved for public release; distribution is unlimited / This thesis was conducted to analyze certain factors affecting first-term attrition from U.S. Naval ships. The Survival Tracking File (STF) was used as the primary data source, and from it files were constructed that permitted three areas of study. First, the overall cohort of a year's worth of enlistees was examined. The survival curve for the cohort was generated and individual monthly cohorts were examined for attrition patterns. Secondly, overall attrition percentages were calculated for individual ships and for classes of ships and these attrition percentages were then examined for differences using statistical techniques. An ANOVA model using transformed data proved accurate in explaining attrition variance. Lastly, a comparison between attrition per month and underway hours per month was made for classes of ships and for individual ships of three specific classes. A rough relationship was observed, between peaks of high underway hours and peaks of attrition. In looking at individual aircraft carriers, the attrition percentage seemed to be inversely proportional to underway hours per month. Several of these findings warrant further investigation so that the Navy may more fully understand its attrition problem and thereby take steps to alleviate it. / http://archive.org/details/descriptiveanaly00carl / Lieutenant, United States Navy

The need for DC power at continuous uninterrupted rates is a reality for ship survival during highly intense combat and regular travel. The new proposed distribution system on the all-electric ship is designed using a DC distribution method (zones) in which the use of transformers and frequency issues/manipulation can be eliminated with the use of power electronics. These power electronic devices can greatly simplify the system and provide more available space, possible cost reduction, and variable control. One key feature is to make sure that the DC buses/systems and converters/rectifiers are protected from faults, transients, and other malicious events that can cause unwanted interference, shutdown, and possible damage or destruction. DC faults can have a detrimental impact on the ship performance. DC protection should allow for high speed and highly sensitive detection of faults enhancing reliability in the supply of electric power. DC fault protection geared towards a lower voltage scenario/system has not yet been studied and analyzed rigorously. The research goal of this work has been to develop a method in which the system can detect a DC fault and perform suppression of the fault and return to normal operating conditions once the fault is removed. The use of power electronics and DC fault detection methods are employed to determine how to best protect the system?s stability and longevity. The findings of the research work have demonstrated that using zero-crossing logic on the AC side of the system is beneficial in DC fault detection. Also, different grounding schemes can produce different effects, whereas some grounding schemes can help protect the system during a disturbance.