Updated Current and Voltage Thresholds for Sustained Arcs in Power Systems

In the late 1990s, satellites began to suffer multiple solar cell string failures, in some cases prematurely ending the satellite mission due to insufficient power. The root cause was determined to be sustained vacuum arcs triggered by electrostatic discharge, which in turn was caused by solar array charging in the ambient environment. Over the following decade, researchers in industry, academia, and national laboratories investigated the current and voltage levels that put solar arrays and other parts of satellite power systems at risk for sustained arcing. That decade of work was combined with independent research on vacuum arcs performed by the power industry in the 1950s to 1980s to delineate rough voltage and current safe and unsafe operating limits in a review published in this journal. Research continued since its publication, particularly in the 50-100 V region used by most solar arrays today. This additional data are combined with the prior results to refine the safe operating I-V limits.