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Title: Heavy-duty explosively operated pulsed opening and closing switches

Abstract

This paper discusses improvements to heavy duty, explosively operated, opening and closing switches to reduce component cost, installation cost, and turnaround time without sacrificing reliability. Heavy duty opening and closing switches operated by small explosive charges (50 g or less) are essential to operation of the 60 MJ Balcones power supply. The six independent modules - a 10 MJ homopolar generator (HPG) and a 6 {mu}H storage inductor - can be discharged sequentially, a valuable feature for shaping the current pulse delivered to loads such as high-energy railguns. Each delayed inductor must be isolated from the railgun circuit with a heavy duty closing switch capable of carrying megampere currents to millisecond duration. Similar closing switches are used to crowbar the railgun as the projectile approaches the muzzle: noise reduction, reduction of muzzle arc damage, and reduction of post-launch perturbation of projectile flight. The switches - both opening and closing - are characterized by microhm resistance in the closed state. Current is carried in metallic conductors. Metal-to-metal seams which carry current are maintained in uniform high pressure contact. Efficient switching is crucial to efficient conversion: rotor kinetic energy to stored inductive energy with {approximately}50% efficiency, stored inductive energy to projectile kineticmore » energy with {approximately}30% efficiency. The switches must operate with a precision and repeatability of 10{sup {minus}5} s, readily achievable with explosives. The opening switches must be structurally and thermally capable of carrying megampere currents for more than 100 ms ({approximately}10{sup 5} C) and develop 10 kV upon opening, stay open for 10{sup {minus} 2} s, and safely and reliably dissipate megajoules of inductive energy in the event of a fault, a failure of the switch to operate or an attempt to commutate into an open circuit.« less

Authors:
; ; ; ; ; ;  [1]
  1. Texas Univ., Austin, TX (United States). Center for Electromechanics
Publication Date:
OSTI Identifier:
5746291
Report Number(s):
CONF-9004136-
Journal ID: ISSN 0018-9464; CODEN: IEMGA
Resource Type:
Conference
Journal Name:
IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States)
Additional Journal Information:
Journal Volume: 27:1; Conference: 5. IEEE symposium on electromagnetic launcher technology, Destin, FL (United States), 1-5 Apr 1990; Journal ID: ISSN 0018-9464
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 30 DIRECT ENERGY CONVERSION; Fu; PLASMA SWITCHES; COST; DESIGN; PULSED MHD GENERATORS; HOMOPOLAR GENERATORS; IMPACT FUSION DRIVERS; RAILGUN ACCELERATORS; ACCELERATORS; DIRECT ENERGY CONVERTERS; ELECTRIC GENERATORS; ELECTRICAL EQUIPMENT; EQUIPMENT; MHD GENERATORS; SWITCHES; 700350* - Plasma Production, Heating, Current Drive, & Interactions- (1992-); 300103 - MHD Generators- Materials, Components, & Auxiliaries; 700470 - Fusion Technology- Power Conversion Systems- (1992-); 700460 - Fusion Technology- Heating & Fueling Systems; Fuels- (1992)

Citation Formats

Peterson, D R, Price, J H, Upshaw, J L, Weldon, W F, Zowarka, R C, Gully, J H, and Spann, M L. Heavy-duty explosively operated pulsed opening and closing switches. United States: N. p., 1991. Web.
Peterson, D R, Price, J H, Upshaw, J L, Weldon, W F, Zowarka, R C, Gully, J H, & Spann, M L. Heavy-duty explosively operated pulsed opening and closing switches. United States.
Peterson, D R, Price, J H, Upshaw, J L, Weldon, W F, Zowarka, R C, Gully, J H, and Spann, M L. 1991. "Heavy-duty explosively operated pulsed opening and closing switches". United States.
@article{osti_5746291,
title = {Heavy-duty explosively operated pulsed opening and closing switches},
author = {Peterson, D R and Price, J H and Upshaw, J L and Weldon, W F and Zowarka, R C and Gully, J H and Spann, M L},
abstractNote = {This paper discusses improvements to heavy duty, explosively operated, opening and closing switches to reduce component cost, installation cost, and turnaround time without sacrificing reliability. Heavy duty opening and closing switches operated by small explosive charges (50 g or less) are essential to operation of the 60 MJ Balcones power supply. The six independent modules - a 10 MJ homopolar generator (HPG) and a 6 {mu}H storage inductor - can be discharged sequentially, a valuable feature for shaping the current pulse delivered to loads such as high-energy railguns. Each delayed inductor must be isolated from the railgun circuit with a heavy duty closing switch capable of carrying megampere currents to millisecond duration. Similar closing switches are used to crowbar the railgun as the projectile approaches the muzzle: noise reduction, reduction of muzzle arc damage, and reduction of post-launch perturbation of projectile flight. The switches - both opening and closing - are characterized by microhm resistance in the closed state. Current is carried in metallic conductors. Metal-to-metal seams which carry current are maintained in uniform high pressure contact. Efficient switching is crucial to efficient conversion: rotor kinetic energy to stored inductive energy with {approximately}50% efficiency, stored inductive energy to projectile kinetic energy with {approximately}30% efficiency. The switches must operate with a precision and repeatability of 10{sup {minus}5} s, readily achievable with explosives. The opening switches must be structurally and thermally capable of carrying megampere currents for more than 100 ms ({approximately}10{sup 5} C) and develop 10 kV upon opening, stay open for 10{sup {minus} 2} s, and safely and reliably dissipate megajoules of inductive energy in the event of a fault, a failure of the switch to operate or an attempt to commutate into an open circuit.},
doi = {},
url = {https://www.osti.gov/biblio/5746291}, journal = {IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States)},
issn = {0018-9464},
number = ,
volume = 27:1,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1991},
month = {Tue Jan 01 00:00:00 EST 1991}
}

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