The characteristics of primary and secondary arcs on a solar array in low earth orbit

摘要

In this paper, the characteristics of the primary arc and secondary arc on a solar array in low earth orbit (LEO) are investigated. The vacuum plasma environment in LEO has been used to study the primary arc and secondary arc of a high-voltage solar array. Silicon solar cells with rigid substrate specimens are used for the experiment. The series-parallel spacing of the silicon solar cells is 1 mm. The string currents of the solar cells are 0.7 A, 1.5 A and 2 A. The primary arc and secondary arc are photographed by high-speed cameras. The differences between the primary arc and secondary arc are observed. The secondary arc can be observed before the primary arc is extinguished. The primary arc is a single arc when the string current is 0.7 A. Multiple arc columns are accompanied by higher arc current. Two arc columns of the primary arc can be observed at 1.5 A string current and 2 A string current. The multiple primary arc columns are related to higher bias voltage. The threshold for sustained arcing is near 145 V/0.7 A, 105 V/1.5 A and 100 V/2 A at 1 mm string gap. Moreover, the transition time of secondary arc formation is analyzed, and found to be about 10-13 mu s. The string currents, string voltages and primary arc have no effect on the transition time of the secondary arc formation.