인공위성 제어 모멘트 자이로의 열적 안정성 분석

Control moment gyroscope (CMG), used for attitude control of spacecraft or satellites, requires thermal analysis to manage and optimize power consumption as it generally operates incessantly for the lifespan in extreme conditions of space. In this study, to more accurately calculate the stabilized temperature of the system, heat generation was applied as a boundary condition in a steady-state thermal analysis, represented as a function of the system and component temperatures. A simplified finite element method (FEM) model using a steady-state-based thermal resistance method were adopted to analyze the factors affecting the thermal stability of the system under extreme conditions at - 20°C and 70°C. At -20°C, under the condition of a total heat dissipation of 28.22 W, the system exhibited a high maximum temperature rise of 43°C on the motor PCB. At 70°C, with a total heat dissipation of 7.2 W, the maximum temperature rise of the system was relatively low at 5.9°C, occurring at the bearing. The results indicated that the temperature of the bearing component strongly influenced the heat dissipation in the system. The friction torque of the bearing, which is the most significant factor regarding heat dissipation and power consumption, was noted to be approximately 10 times higher at -20°C than at 70°C. Consequently, the heat dissipation from the bearing was approximately 4 times higher, whereas the heat dissipation from the motor was approximately 10 times higher at -20°C than at 70°C.