Mathematical model of a battery discharge unit for space applications

The paper describes a mathematical model of high frequency DC-DC converter based on the push-pull circuit with autotransformer. Similar schemes of converters are widely used as battery discharge units in power supply system of satellites due to high performance characteristics and reliability. The paper provides a brief overview of the characteristics of the widely used solutions and defines the issue of developing a mathematical model for scheme to be analyzed. The mathematical description of electromagnetic processes is based on the state-space model. The obtained mathematical model for this circuit seems to be the new and allows synthesis procedure of a closed-loop control. In the paper internal stability analysis has been done for the output voltage stabilization mode and for the input current stabilization mode as well. Simulation results of transient processes in converter operated with open-loop control system are presented. They are obtained with numerical simulation of the mathematical model developed in the software package Matlab/Simulink.