Comparison of Peak Power Tracking Based Electric Power System Architectures for CubeSats

CubeSats have been widely used for space research due to lower cost and faster development. The electric power system (EPS) is one of the key subsystems of CubeSat which powers all the other subsystems. One of the important steps in the EPS design is the selection of EPS architecture which should be done considering overall efficiency, battery size, reliability, and simplicity of control. In the literature, a general comparison between different architectures is performed without considering the mission parameters, power generation profile, and load profile based on the operational modes. Thus, the best possible EPS architecture may not be selected in the design phase. Therefore, the main objective of this article is to develop a systematic methodology to compare various peak power tracking EPS architectures of CubeSat in terms of orbital efficiency for all possible modes of operation, component count, reliability, and battery size to meet the required number of cycles of charge/discharge for the given mission duration. The proposed methodology has been demonstrated using the real data and scenarios of MYSAT-1, which is a 1U CubeSat developed and launched by Khalifa University. The results demonstrate that EPS architecture with series-connected maximum power tracking converters for solar panels and unregulated dc-bus has the highest efficiency for all operating modes, lower component count, higher reliability, and minimum battery capacity or longer lifetime for the same battery specifications.