Analysis and Design of the Dual-Core Cascaded Buck-Push-Pull Converter

This paper presents the analysis and design of a dual-core cascaded buck–push–pull converter intended for high-reliability aerospace and satellite power supply applications. The proposed topology integrates a buck regulation stage with a dual-core current-fed push–pull isolation stage, ensuring a continuous energy-transfer path to the output under the proposed winding-ratio and overlap-ratio design conditions. Additionally, the secondary-side synchronous rectifiers are self-driven, eliminating the need for an additional gate driver and thereby simplifying the gate-driver circuitry. The dual-core structure also enables core reset through the tertiary windings, mitigating the risk of core saturation attributed to transformer mismatch. Design guidelines for selecting the transformer winding ratio and duty-overlap ratio are derived to ensure stable operation and complete core reset. The proposed analysis and design guidelines are verified through SIMPLIS simulations and a 15-W hardware prototype, confirming the feasibility of the proposed converter.