Abstract:  To investigate temperature distributions of solar panels in orbit under two operating conditions (full and half load), a thermal model was established by FEM analysis software I-DEAS TMG. The substrate of solar panels, which is composed of several composite materials, could be treated as an orthotropic plate, and the equivalent thermal resistance method is employed to derive the equivalent thermal conductivity of solar panels. The simulation results indicate that the temperatures of solar panels change periodically after five circles around the earth, and the range of temperatures under half load operating condition is wider than that under full load operating condition. Additionally, both the temperature difference through the thickness of solar panels and its first time derivative are highest when solar panels enter the eclipse, and these two values of half load operating condition are higher compared with those of full load operating condition.

Key words: solar panels, half load operating conditions, equivalent thermal conductivity, temperature distributions