Our proposed miniature spacecraft power management and distribution (PMAD) system is intended to operate at very high efficiency over a 100:1 insolation range, useful for deep space planetary and probe missions. The approach is a hybridization of segment switched solar array control and an advanced peak-power tracking function that enables very high conversion efficiency at Low Intensity Low Temperature (LILT) conditions. The system is fault tolerant because of inherent multiple redundancy, also accommodates traditional redundancy approaches and is autonomous and self-controlling. The primary objective of Phase I effort is verification of our design concept, implemented by four tasks: 1) Research Previous Methods, 2) Computer Simulation and Concept Optimization, 3) Fabricate and Test Circuit Breadboards, and 4) Generate Final Technical Report. Tasks 2 and 3, the bulk of technical effort, will be facilitated with concurrent, recursive analog circuit simulation and breadboard testing of control circuits utilizing our programmable solar array simulator and computer-controlled test instruments. Our proposed DSP approach is expected to improve the control system signal-to-noise ratio by a factor of 100 over previous approaches allowing higher frequency operation, thereby greatly reducing system size and mass. Many of the deep-space planetary, asteroid and cometary missions now planned by NASA could greatly benefit from this innovation, such as Mars Aerial Photography (MAP), Saturn Mini-Probe (SMP), Cometary Coma Chemical Composition (C4), and Near Earth Asteroid Rendezvous (NEAR).The elements of this system apply directly to terrestrial solar power processing needs. Use of this system will enable increased efficiency of solar power processing in many applications that demand low power under adverse insolation conditions. Examples are portable solar-recharged communications systems, solar-powered remote telemetry stations, autonomous geological and seismological monitoring stations, and portable remote field equipment. The railroad industry, for example could improve the performance of hundreds of remote telemetry sights by taking advantage of technology developed under this contract. Under adverse conditions caused by cloud cover, accumulated dirt on solar panel cover glass, and reduced insolation at low incidence angles, this system will greatly improve captured energy. Because such systems are generally designed to provide adequate power margin under unfavorable conditions, use of this innovation would potentially reduce the size and mass of such systems by 50%.
Keywords: Phase_I, NASA, Abstract, FY94
