Stability study of spacecraft electrical power system with constant-power loads

Stability of spacecraft electrical power system is analyzed in this paper with constant-power load. Such loads tend to destabilize the system due to their negative dynamic input resistance characteristics as viewed from the main bus or an input filter. In this paper, we have studied the interactions of bus filter with a dc-dc converter acting as constant-power load in the presence of power conditioning equipment. As a result it is demonstrated that the impedance of bus conditioning equipment has a significant influence on the stability of the whole system. A qualitative study of this effect is presented in this paper for sunlight mode as well as for eclipse mode of operation. The theoretical conclusions of this paper are verified with the simulation results.