A Field Based, Self-Excited Compulsator Power Supply for A 9 MJ Railgun Demonstrator

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Walls, A. W.
Pratap, S.B.
Brunson, G.W.
Cook, K.G.
Herbst, J.D.
Manifold, S.M.
Rech, B.M.
Thelen, R.F.
Thompson, R.C.
Brinkman, W.G.

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Fabrication efforts have begun on a field-based compulsator for firing 9 MJ projectiles from a railgun launcher. The machine is designed to store 200 MJ kinetic energy and fire a salvo of nine rounds in three minutes at velocities between 2.5 and 4.0 km/s. Prime power required to meet this firing schedule is 1.865 kW, and will be supplied by a gas turbine engine. It is also possible to fire a burst of two shots in rapid succession, if desired. Operating speed of the machine is 8250 r/min and it has design ratings of 3.2 MA peak current and 20 GW peak power into a 9 MJ railgun load. A two-pole configuration is used for pulse-length considerations, and selectivity passive compensation is used to produced a relatively flat pulse and limit peak projectile acceleration to about 980000 m/s2. Other distinguishing features include an air core magnetic circuit, separate rotor armature windings for self-excitation and railgun firing, ambient temperature field coils, and excitation field magnetic energy recovery capability. A detailed description of the machine as designed, and its auxiliary and control systems, is provided. Fabrication and assembly methods are reviewed, and the current status of the project is discussed


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A.W. Walls, S.B. Pratap, G.W. Brunson, K.G. Cook, J.D. Herbst, S.M. Manifold, B.M. Rech, R.F. Thelen, R.C. Thompson, W.G. Brinkman, “A field based, self-excited compulsator power supply for a 9 MJ railgun demonstrator,” IEEE Transactions on Magnetics, vol. 27, no. 1, Jan. 1991, pp. 335-349.