With the proliferation of electromagnetic launch systems presently being designed, built, or studied, there appears to be no limit to their application. One of the intriguing applications is electromagnetically catapulting aircraft from the deck of an aircraft carrier. The US Navy had foreseen the substantial capabilities of an electromagnetic catapult in the 1940s and built a prototype. However, it was not until the recent technical advances in the areas of pulsed power, power conditioning, energy storage devices, and controls gave credence to a fieldable electromagnetic aircraft launch system. This paper presents the U.S. Navy's Electromagnetic Aircraft Launch System (EMALS) being developed in partnership with Kaman Electromagnetics (Hudson, MA). It addresses the EMALS's present design and the technologies involved, as well as the ship and operational impacts, advantages, disadvantages, and compatibility issues for today's and tomorrow's carriers. >

Electromagnetic aircraft launch system-EMALS

Secretary of the Navy Richard Danzig announced on Jan. 6 that the Land Attack Destroyer (DD 21) will be the US Navy's first class of ships designed and built with electric drive featuring an integrated power architecture. In addition to supporting the needs of DD 21, this power system architecture was described as a future technology enabler for advanced energy sources and ship capabilities. The warfighting benefit of one such capability, rail guns, was recently evaluated by the CNO's Strategic Studies Group. This paper discusses aspects of the integration of such a capability into a future destroyer with an integrated power system.

Electric ship drive and power system

https://www.matlabi.ir/wp-content/uploads/bank_papers/g_paper/g196_Matlabi.ir_Analysis%20of%20synchronous%20machine%20modeling%20for%20simulation%20and%20industrial%20applications.pdf

Analysis of synchronous machine modeling for simulation and industrial applications

A new approach on synchronous generator (SG) output voltage control is presented. The originality of such a strategy is based on the excitation structure that integrates a permanent-magnet generator combined with a modern control method: the H infin. The main motivation of this paper is the debatable results obtained with the classical excitation structure controlled by a traditional PID controller. The SG model as well as the control strategy will be presented. The implementation in real time domain and a comparison with the classical structure will allow us to prove the efficiency of the proposed structure compared to the classical one as regards the reference tracking and signal quality.

Synchronous Generator Output Voltage Real-Time Feedback Control via $H_\infty$ Strategy

Future naval shipboard power systems for electrothermal chemical guns will require power conditioning to charge capacitors from a rectified generator source. This paper describes results of laboratory testing involving two low voltage capacitor charging schemes. These experiments demonstrate the power conditioning equipment's voltage and current control characteristics. The first sequence of tests utilized a phase-controlled rectifier to control the current. A series of constant phase delay angles and a predetermined phase delay angle profile were tested to produce a constant current charge on the capacitors. The second sequence utilized generator field control to ramp the charge voltage through a diode bridge to charge the capacitors. Using the results of each configuration, an optimum design of simultaneous current and voltage control can be developed. The control aspects of using combined generator field control and rectifier current control is addressed. >

Current and voltage controlled capacitor charging schemes

Alternative power system architectures and interface technologies for driving high-energy pulsed loads from the propulsion equipment of naval surface combatants are compared. Gas turbine mechanical and gas turbine integrated electric drive propulsion trains are considered as prime power sources. Focus is on the energy path between the ship's prime power and the pulsed load, comparing system candidates on a size, weight, and component cost basis. A capacitor-based pulse forming network (PFN) supplying an electrothermal chemical gun is utilized as the common load for all configurations. Results indicate that dedicated auxiliary generators driven from propulsion gas turbine engines are the preferred method of powering electric gun PFNs from ship drive-train equipment. Auxiliary generator-based systems are compact and lightweight over a wide power range, are equally attractive with both electric and mechanical drive trains, and demonstrate retrofit potential to the current fleet. >

T.J. Doyle

Papers

Propulsion powered electric guns-a comparison of power system architectures