In the realm of space exploration, maintaining a stable and reliable power supply is crucial for the sustained and uninterrupted operation of artificial satellites. However, the unpredictable and often harsh space environment necessitates a redundant design for space power supplies to enhance overall reliability. In light of this, this paper introduces a full-bridge converter employing a series-parallel topology, which augments input voltage redundancy through a combination of serial and parallel connections. Furthermore, a dual-loop Proportional-Integral (PI) control feedback system has been devised, along with a comprehensive analysis of system stability to ensure the optimal performance of both output voltage and current. To validate the efficacy of the series-parallel topology and the feedback system, a complete circuit is constructed, and extensive simulations are carried out under diverse conditions.