Minimizing Output Ripple in Satellite BDRs Using Fuzzy Logic Control

The conventional Weinberg converter is commonly employed in battery discharge regulators (BDRs) within the electrical power systems of geostationary satellites due to its high efficiency, continuous input and output currents, and the soft switching characteristics of both switches and diodes. However, a major limitation of this topology is the significant output current ripple that occurs during diode commutation. This ripple leads to increased output voltage fluctuations and higher root mean square (RMS) currents, which can degrade the lifespan of the bus capacitors and necessitate larger capacitance values—ultimately impacting the size, reliability, and operational lifespan of the satellite. Therefore, minimizing output current ripple in the BDR is essential for enhancing the overall performance of the satellite’s power system. To overcome this challenge, this study introduces an improved Weinberg converter designed to reduce both output current and voltage ripple, while also minimizing magnetizing current offset in the coupled inductor. The proposed topology retains the advantages of the conventional design, including high efficiency and soft switching for all switching devices, and effectively eliminates diode reverse recovery issues. Simulation results for a 750 W prototype validate the improved converter’s performance and demonstrate its suitability for advanced satellite power systems.