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Advanced Electrical Power Systems Thrust

Overview

Advanced Electrical Power Systems (AEPS) will provide the enabling science, technology and design tools to allow electrical power systems, electric propulsion, and auxiliary systems to meet future mission and affordability requirements. AEPS technologies will be applicable to all future surface ship, aircraft carrier, and submarine platforms.

This thrust envisions an "Electrically Reconfigurable Power System," which enables:

A more survivable ship
Integrated systems for ship control, C4I, engineering plant, and damage control
Leveraging of commercial technology
Continuously upgraded modular architectures (hardware and software)
Near-zero emission of pollutants such as NOX and SOX
Low acoustic signature
Pulsed and high power weapon systems

The Advanced Electrical Power System thrust applies architecture and technology changes to increase power and energy density; reduce size, weight, and cost (10x); and increase survivability and reliability of electrical systems.

Systems

To implement electric drive using current technology, submarines and smaller surface combatants would have to give up excessive payload space, thus restricting future missions, not expanding them. If the size and weight of power electronics can be substantially reduced, then electric drive for smaller combatants, submarines, and littoral warcraft will be enabled.

Other future Navy systems such as Electromagnetic Aircraft Launch System (EMALS), Electromagnetic Aircraft Recovery System (EARS), and advanced pulsed power weapons also will require power electronics to control and manage shipboard energy to meet their operating needs. Conventional power electronic systems and design practices result in systems that are 10x too large and heavy.

Also, highly coupled systems with limited available energy and highly non-linear and pulsing loads create difficult stability problems. These problems increase as power density and system coupling increases. Advanced control architectures are needed that will extend throughout the system to address complex electrical equilibrium considerations, both static and dynamic. Furthermore, Navy requirements (quiet operation, high-impact shock, and shipboard power quality) are not satisfied by COTS products.

Approach

Energy conversion is fundamental to future electrical power systems. As a result, future systems will require new electrical, electromechanical, electrochemical, electrothermal, and photoelectric energy conversion processes and technologies. The AEPS thrust has the following sub-thrusts that develop ship-wide energy conversion concepts, technologies and machinery for future electric warships:

Electromechanics -- control, modeling/simulation, and stability;
Electrochemical Energy Conversion Technology -- fuel cells;
Electrical Energy Conversion Technology -- machines, topologies, and components (such as inverters, converters, and solid-state protection devices);
Electromechanical Energy Conversion Technology -- machines, topologies, and components (such as actuators, generators, and motors);
Electrical Power Systems -- energy management, reconfiguration, and Open Plug and Play architectures.

The technical strategies include:

Cost Reduction -- Develop modular least-replaceable units to reduce acquisition and total ownership cost;
Efficiency -- Control thermal, mechanical, and electrical losses to increase power density and reduce signatures;
System Reconfiguration -- Develop active filtering for nonlinear and pulsing loads to enable fight-through power for all mission-critical functions;
Regulation & Stability -- Develop integrated control methodologies, algorithms, and architectures to enable dynamic reconfiguration of electrical systems and to achieve reduced manning;
Energy Generation & Storage -- Develop distributed power generation and rapid power-transfer and energy storage for high-power electric weapons, sensors, and countermeasures;
Energy Management & Control -- Develop physics-based models of power networks and simulation of total-ship power systems to enable dynamic reconfiguration of electric, auxiliary, and damage control systems, leading to full automation.

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