Source Load Interface Stability Analysis of Spacecraft Power Systems

Abstract

The loop gain analysis technique has been applied for stability margins of spacecraft power systems at the interface of the source and load. The loop gain analysis has originally been developed to derive an input impedance specification requirement for distributed power systems. In this paper, source and load interaction analyses of a spacecraft power system are presented using a system loop gain, which is represented by a ratio of source impedance to load’s input impedance in the frequency domain. The loop gain analyses are performed with corresponding Nyquist plots for better interpretation of stability margins. Transient simulations using PSPICE models also verify the impedance analysis results. The theoretical methods of determining stability margins at the source and load interfaces are practically applied to the spacecraft power system to demonstrate how to use the simple impedancemagnitude comparison technique and the loop gain analysis technique.