High Voltage Conductors in Spacecraft
Abstract
Future solar arrays are being designed for much higher voltages in order to meet high power demands at low currents. Unfortunately, negatively biased high voltage solar cells have been observed to arc when exposed to the low earth orbit plasma environment. Analytical and numerical models of this arcing phenomenon on conventional solar cells have been developed which show excellent agreement with experimental data. With an understanding of a mechanism for arcing, it is possible to determine methods of arc rate mitigation and to predict arc rates for experiments. Using the previously developed models, it was determined that the arcing rate can be decreased by (1) increasing the interconnector work function, (2) increasing the thickness of the coverglass and adhesive, (4) decreasing the ratio of the coverglass/adhesive dielectric constants, and (5) overhanging the coverglass. Of these, methods (4) and (5) show the most promise in reducing or even eliminating arcing. In addition, arcing rates were predicted for the high voltage biased arrays of the Air Force's Photovoltaic and Space Power Plus Diagnostics experiment (PASP Plus) and NASA's Solar Array Module Plasma Interactions Experiment (SAMPIE). These predictions provide both expectations for the missions and a means to test the numerical and analytical models in the space environment for different solar cell technologies. Finally, a numerical model of the arc initiation process was also developed for wrap-through-contact cells, but experimental data is not available for comparison.... Arcing, High voltage solar array.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 07, 1993
- Accession Number
- ADA267268
Entities
People
- Daniel Hastings
Organizations
- Massachusetts Institute of Technology