PROBLEM 4: A Project considers a Mars Lander to be located on Martian surface equipped with a power system which is a co

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Problem 4 A Project Considers A Mars Lander To Be Located On Martian Surface Equipped With A Power System Which Is A Co 1 (473.73 KiB) Viewed 42 times

PROBLEM 4: A Project considers a Mars Lander to be located on Martian surface equipped with a power system which is a combination of solar panel/ secondary batteries. The solar visibility of the lander during a Martian day (24hr39min) is 55% with an average intensity of 60%. The solar irradiance for Mars is about 43% of that of the Earth. The power from battery is needed for up to 75 hours considering environmental issues and excess power needs. Saft's space-qualified Li-ion cell 110 Calculate the area and mass of the solar panels required to provide 602W of average power per Martian day. The night time power required is 40% of the day time power. Use UTJ cells with a max efficiency of 36% at a cell temperature of -50°C. The UTJ cells provide 31% at a cell temperature of 25°C. Assume direct energy transfer scheme. Use typical UTS cell values for radiation (0.5%/year) and design/assembly losses of 0.91. The average panel temperature is 290°K. The system is designed to operate for 2 Martian years. (35p) Design the battery pack required (cell configuration, mass and W-hr) for the max eclipse time using the most suitable VES battery cells (see side table) to provide eclipse power with a DOD of 60% for a Bus Voltage of 120V+-5V with 10% transmission losses. Based on the design parameters, carry out a trade analysis to choose the best battery cell for the mission. Consider packaging weight increase as well. (30p). VES 140 VES 180 VES 16 Nominal 39 50 4.5 capacity (Ah Mean voltage at / 1.5 3.6 3.6 3.6 End of charge voltage (M 4.1 4.1 4.1 Energy Whi 140 180 16 Specific energy Wh/kg 125 165 155 Height (mm) 250 250 60 Diameter mm 52 53 33 Weight (kg 1.13 1.11 0.155 Main application GOMED GEDEO LED, CO