성층권 태양광 드론의 비행 프로파일에 기반한 인버터의 신뢰성 분석

Abstract

The stratospheric solar-powered drone is being developed to perform various missions such as weather observation, communication, surveillance, and reconnaissance by receiving power through solar cells at altitudes of 18 km to 20 km. The inverter is a key component for the operation of the stratospheric solar-powered drone, and ensuring reliability is of utmost importance for long-duration flights. Therefore, this study aims to predict the lifespan and analyze the reliability of the inverter used in the stratospheric solar-powered drone by assessing the damage level due to cumulative fatigue based on the temperature changes at the IGBT (Insulated Gate Bipolar Transistor) junction, using the EAV-3 flight profile developed by the Korea Aerospace Research Institute. Simulation results showed that the maximum stress occurs during the ascent from the ground to the stratosphere, and maintaining descent minimizes temperature changes at the junction, resulting in less damage. The analysis indicated that the expected lifespan of the IGBT is approximately 98.8 years. This interpretation method is expected to be useful for analyzing the reliability of inverters that will be applied to future stratospheric solar-powered drones.