To obtain the thermal performances of a motor controller working in stratosphere

numerical simulation based on software Icepak was performed. To confirm the accuracy of the numerical model

aground environmental simulation test and a stratospheric flight test were carried out. Results showed that the numerical model equation can simulate the thermal performance of the controller well. The influences of the cooling method of forced convection using an inner fan on the thermal performances were researched. The numerical simulation and flight test results showed that the thermal design of the controller was acceptable in view of stable working. Surface solar radiation should be taken into account

as it will influence the internal temperature. The research results provide important references for the engineering application of the stratospheric motor controller.