A predictive control based management policy in a spacecraft power system

Abstract

This paper presents a control architecture for power management of a spacecraft system with multi-task flight. In view of both flight-mode complexity and load diversity, a novel power management policy based on predictive control is proposed and will be applied to the spacecraft system. A sequential switching shunt regulator (S3R) based power generation model has been established to predict the primary power supply of the spacecraft. The in-orbit load demand is strongly dependent on the pre-planned flight procedures. Then a battery capacity based power balance policy has been made to guarantee the balance state during a complete orbital period. Once in a state of unbalanced power system, unimportant loads will be excluded when a specific flight mode is applied. A judgment matrix based priority policy has been formulated to classify the in-orbit loads. As a bonus offered by the Power Management and Distribution (PMAD), weights are introduced into our load management system to schedule and establish the load priority. To establish the load priority list, a set of crucial parameters involving working-mode coefficient, grading coefficient and comprehensive indices (in terms of unquantized coupling weights, power consumption and working hours characterized quantificationally) has to be well defined using judgment matrix. Using the judgment matrix, the power system is capable of modulating electrical load suitable to supplied power, with updated priority list generated accordingly.