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Stability of large DC power systems using switching converters, with application to the international space stationAs space direct current (dc) power systems continue to grow in size, switching power converters are playing an ever larger role in power conditioning and control. When designing a large dc system using power converters of this type, special attention must be placed on the electrical stability of the system and of the individual loads on the system. In the design of the electric power system (EPS) of the International Space Station (ISS), the National Aeronautics and Space Administration (NASA) and its contractor team led by Boeing Defense & Space Group has placed a great deal of emphasis on designing for system and load stability. To achieve this goal, the team has expended considerable effort deriving a dear concept on defining system stability in both a general sense and specifically with respect to the space station. The ISS power system presents numerous challenges with respect to system stability, such as high power, complex sources and undefined loads. To complicate these issues, source and load components have been designed in parallel by three major subcontractors (Boeing, Rocketdyne, and McDonnell Douglas) with interfaces to both sources and loads being designed in different countries (Russia, Japan, Canada, Europe, etc.). These issues, coupled with the program goal of limiting costs, have proven a significant challenge to the program. As a result, the program has derived an impedance specification approach for system stability. This approach is based on the significant relationship between source and load impedances and the effect of this relationship on system stability. This approach is limited in its applicability by the theoretical and practical limits on component designs as presented by each system segment. As a result, the overall approach to system stability implemented by the ISS program consists of specific hardware requirements coupled with extensive system analysis and hardware testing. Following this approach, the ISS program plans to begin construction of the world's largest orbiting power system in 1997.
Document ID
Document Type
Technical Memorandum (TM)
Manners, B.
(NASA Lewis Research Center Cleveland,OH United States)
Gholdston, E. W.
(Rockwell International Corp. Canoga Park, CA United States)
Karimi, K.
(Boeing Co. Seattle, WA United States)
Lee, F. C.
(Virginia Polytechnic Inst. and State Univ. Blacksburg, VA United States)
Rajagopalan, J.
(Virginia Polytechnic Inst. and State Univ. Blacksburg, VA United States)
Panov, Y.
(Virginia Polytechnic Inst. and State Univ. Blacksburg, VA United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1996
Subject Category
Spacecraft Propulsion And Power
Report/Patent Number
IECEC Paper 96-96079
NAS 1.15:107281
Meeting Information
Meeting: Intersociety Energy Conversion Engineering Conference
Location: Washington, DC
Country: United States
Start Date: August 11, 1996
End Date: August 16, 1996
Sponsors: American Nuclear Society, American Inst. of Chemical Engineers, Society of Automotive Engineers, Inc., American Society of Mechanical Engineers, Institute of Electrical and Electronics Engineers, American Inst. of Aeronautics and Astronautics
Accession Number
Funding Number(s)
PROJECT: RTOP 323-99-01
Distribution Limits
Work of the US Gov. Public Use Permitted.
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