Analysis of Bidirectional Step-Up/Down Partial Power Converter Based on Full-Bridge Push-Pull Circuit

The demand for DC power conversion is increasing in high-power renewable energy. Series-connected partial power converter (S-PPC) has gained attention in scenarios such as battery storage, electrolytic hydrogen production, electric vehicle fast charging, and new energy power generation due to high efficiency, high power density, and low cost. Bidirectional stepup/down (BDSUD) four-quadrant S-PPC can minimize power handling and provide better performance. However, it is difficult to analyze due to many operating modes and complex power flow. The research on S-PPC principle analysis is mostly based on the connection of the main power feed-forward branch but lacks the analysis of partial power transmission path from the perspective of specific circuit. This paper analyzes the circuit operation modes of the BDSUD S-PPC based on the full-bridge push-pull (FBPP) circuit during the switching cycle. It reveals how the partial power processing is realized from the internal component point of view by analyzing the power flow inside. The related analysis is verified in simulation.