Modeling analysis and Design of Battery Chargers for Micro-nano SAR Satellites

With the development of modern commercial satellites, the micro-nano SAR satellites with low-cost, light-weight, multi-functional, and highly-integrated features are ushering lately. Due to short working time and high peak power of SAR loads, a set of high-voltage load batteries must be specially configured for SAR loads, supplying larger power with the same current. This paper proposes an isolated boost converter with a push-pull topology for constant current and constant voltage charging of the lithium batteries, and the charger converter uses a dual-loop control strategy of peak current control method to achieve constant current and constant voltage charging performance. The AC small signal equivalent model of the converter is established. Finally, the experimental verification is carried out on the charger prototype. The experimental results verify the correctness of the analysis and the validity of the design, which can meet the requirements of SAR load battery charging.