Advanced EPS Component Models for Accurate Satellite EPS Simulation
7th International Energy Conversion Engineering Conference
Detailed models for all EPS components are required for accurate Electric Power System (EPS) simulations of satellites in various LEO, MEO, and GEO missions. Older and outdated models had used various power margins to over-estimate the size and weight of the satellite EPS for a given mission. Today's models incorporate the use of many sets of test data from various testing facilities to much better and more accurately predict the behavior of each component. This paper summarizes the library of
... zes the library of the various component models currently used in such satellite simulations. The components modeled include solar array cells, solar array string and group diodes, solar array harnesses, battery cells, battery recharging efficiencies, battery charge control, battery heaters, bus diodes, cabling, and wiring. The models use various input variables in their simulation, including the effects of bus voltage, current, temperature, and age. These component models are used within the Power Suite Tools code within Lockheed Martin to perform sizing trades and BOL and EOL margin analyses. They can also be used to compare EPS behavior from on-orbit data, and to predict future transient behavior in worst-case scenarios. One major concern in the operation of such satellite systems is the prediction of the maximum state-of-discharge (SOD) of the batteries during the most challenging mission phases. The use of these PTS code models enables much more accurate simulations of EPS behavior, battery degradation, and lifetime estimates that are needed in the Aerospace Industry today.