The Office of Naval Research is sponsoring work by the Electric Ship Research and Development Consortium (ESRDC) in pursuit of a long-term vision to develop a revolutionary new “electric ship” power-generation architecture for shipboard systems that will be capable of powering all future weapons and sensors, as well as propulsion and all ship services.
Sharon Beermann-Curtin, program officer for ONR’s Sea Warfare and Weapons Department, said that an important first step is successful demonstration of a prototype solid-state power-conversion module (PCM) that incorporates semiconductors fabricated from silicon carbide. This material is capable of operating at higher voltages, frequencies, and temperatures than silicon, now widely used for semiconductors.
The prototype is being evaluated at the Center for Advanced Power Systems at Florida State University, one of eight ESRDC members (the others are the Massachusetts Institute of Technology, the University of Texas, the University of South Carolina, Mississippi State University, Purdue University, the U.S. Naval Academy, and the Naval Postgraduate School).
Beermann-Curtin said that “the only way we’re going to get to the future [for shipboard power] is to enable a new ship architecture.” Such an architecture is needed, she said, to simultaneously support future sensors, such as air- and missile-defense radar (AMDR), advanced weapons including lasers and railguns, and the electromagnetic aircraft-launch system (EMALS) for aircraft carriers.
The advanced solid-state architecture emerges from the Defense Advanced Research Projects Agency’s High-Power Electronics program and ONR’s Power Electronic Building Blocks program. The effort, said Beermann-Curtin, now is aimed at surface ships that will follow not only today’s shipbuilding programs, but also those now in development, including the Flight III Arleigh Burke–class destroyers, which the Navy expects to start building beyond 2015.
Most of today’s surface combatants use either gas-turbine or diesel engines as “prime movers,” along with generators, switches, power converters, and distribution systems to generate propulsion power. Ship systems, including weapons and sensors, are supported by a separate power architecture.
Beermann-Curtin pointed out that the Navy has long explored technologies and ship designs that would integrate generation and distribution of high-quality power for propulsion, weapons, and other ship systems.
In September 1988, following completion of a Ship Operational Characteristics Study, Chief of Naval Operations Admiral Carlisle A. H. Trost said, “I am declaring that integrated electric drive, with its associated cluster of technologies, will be the method of propulsion for the next class of surface battle-force combatants.” The power architecture envisioned in the study offered payoffs in increased power for weapons and other ship systems for the Navy’s next destroyer program, then called DDX.
In January 2000, Secretary of the Navy Richard Danzig announced that ongoing electric-drive research would lead to use of integrated electric drive for the destroyer program, renamed DD-21.
Since then, the Navy has made significant strides in moving toward electric-ship architectures. The amphibious-assault ship USS Makin Island (LHD-8), which joined the Fleet in October 2009, is fitted out with a hybrid electric-propulsion system that integrates gas-turbine engines for high speeds and auxiliary electric motors that are more efficient at lower speeds. The America (LHA-6), commissioned in October 2012 as the first ship of a new class replacing the Tarawa class of amphibs, incorporates a similar hybrid architecture.
The three-ship Zumwalt class of next-generation destroyers, now under construction at Maine’s Bath Iron Works, incorporates a fully integrated power system for propulsion, weapons, and ship services.
Beermann-Curtin said that while these steps represent progress toward a fully integrated system, they still limit the level of power that can be generated. The solution, she said, is a shift to solid-state power electronics that will lead to dramatic reductions in size and weight of the power architecture, as well as order-of-magnitude increases in power capacity.
Following completion of the testing now under way at the Center for Advanced Power Systems, the ONR solid-state PCM will be tested at the Navy’s AMDR test site in 2015. If successful, the testing will lead to full integration with the AMDR.