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  • 1
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    Power conditioning techniques (1989)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The technological developments required to reduce the electrical power system component weights from the state-of-the-art 2.0 kg/kW to the range of 0.1 to 0.2 kg/kW are discussed. Power level requirements and their trends in aerospace applications are identified and presented. The projected weight and launch costs for a 1MW power converter built using state-of-the-art technology are established to illustrate the need for reliable, ultralightweight advanced power components. The key factors affecting converter weight are given and some of the tradeoffs between component ratings and circuit topology are identified. The weight and launch costs for a 1MW converter using 0.1 kg/kW technology are presented. Finally, the objectives and goals of the Multi-Megawatt Program at the NASA Lewis Research Center, which is funded by the SDIO through the Air Force, are given.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-102577 , E-5408 , NAS 1.15:102577 , Neutral Particle Beam Technology Symposium; Jul 18, 1989 - Jul 21, 1989; Monterey, CA; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 2
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    Electrical properties of teflon and ceramic capacitors at high temperatures (1992)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Space power systems and components are often required to operate efficiently and reliably in harsh environments where stresses, such as high temperature, are encountered. These systems must, therefore, withstand exposure to high temperature while still providing good electrical and other functional properties. Experiments were carried out to evaluate Teflon and ceramic capacitors for potential use in high temperature applications. The capacitors were characterized in terms of their capacitance and dielectric loss as a function of temperature, up to 200 C. At a given temperature, these properties were obtained in a frequency range of 50 Hz to 100 kHz. DC leakage current measurements were also performed in a temperature range from 25 to 200 C. The results obtained are discussed and conclusions are made concerning the suitability of the capacitors studied for high temperature applications.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-105569 , E-6894 , NAS 1.15:105569 , 1992 International Symposium on Electrical Insulation; Jun 07, 1992 - Jun 09, 1992; Baltimore, MD; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 3
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    Electrical characterization of glass, teflon, and tantalum capacitors at high temperatures (1991)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Dielectric materials and electrical components and devices employed in radiation fields and the space environment are often exposed to elevated temperatures among other things. Therefore, these systems must withstand the high temperature exposure while still providing good electrical and other functional properties. Experiments were carried out to evaluate glass, teflon, and tantalum capacitors for potential use in high temperature applications. The capacitors were characterized in terms of their capacitance and dielectric loss as a function of temperature up to 200 C. At a given temperature, these properties were obtained in a frequency range of 50 Hz to 100 kHz. The DC leakage current measurements were also performed in a temperature range from 20 to 200 C. The obtained results are discussed and conclusions are made concerning the suitability of the capacitors investigated for high temperature applications.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-104517 , E-6387 , NAS 1.15:104517 , 1991 Conference on Electrical Insulation and Dielectric Phenomena; Oct 20, 1991 - Oct 24, 1991; Knoxville, TN; United States
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    NASA TECHNICAL REPORTS
  • 4
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    High temperature dielectric properties of Apical, Kapton, Peek, Teflon AF, and Upilex polymers (1992)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Reliable lightweight systems capable of providing electrical power at the magawatt level are a requirement for future manned space exploration missions. This can be achieved by the development of high temperature insulating materials which are not only capable of surviving the hostile space environment but can contribute to reducing the mass and weight of the heat rejection system. In this work, Apical, Upilex, Kapton, Teflon AF, and Peek polymers are characterized for AC and DC dielectric breakdown in air and in silicone oil at temperatures up to 250 C. The materials are also tested in terms of their dielectric constant and dissipation factor at high temperatures with an electrical stress of 60 Hz, 200 V/mil present. The effects of thermal aging on the properties of the films are determined after 15 hours of exposure to 200 and 250 C, each. The results obtained are discussed and conclusions are made concerning the suitability of these dielectrics for use in capacitors and cable insulations in high temperature environments.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA-TM-105753 , E-7161 , NAS 1.15:105753 , 1992 Conference on Electrical Insulation and Dielectric Phenomena; Oct 18, 1992 - Oct 21, 1992; Victoria, British Columbia; Canada
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 5
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    Electrical characterization of a Mapham inverter using pulse testing techniques (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The use of a multiple pulse testing technique to determine the electrical characteristics of large megawatt-level power systems for aerospace missions is proposed. An innovative test method based on the multiple pulse technique is demonstrated on a 2-kW Mapham inverter. The concept of this technique shows that characterization of large power systems under electrical equilibrium at rated power can be accomplished without large costly power supplies. The heat generation that occurs in systems when tested in a continuous mode is eliminated. The results indicate that there is a good agreement between this testing technique and that of steady state testing.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Intersociety Energy Conversion Engineering Conference; Aug 12, 1990 - Aug 17, 1990; Reno, NV; United States
    Format: text
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    NASA TECHNICAL REPORTS
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