A Branch-Sharing Partial Power Converter with Bipolar Voltage Regulation

The input-parallel output-series (IPOS) partial power converter (PPC) which is composed of isolated cell and dc-dc cell is regarded as a promising solution with high-efficiency and high density because only a partial power is delivered by dc-dc cell to regulate the voltage. In the paper, a branch-sharing partial power converter with bipolar voltage regulation range for dc distribution power systems is proposed. In the proposed converter, a half-bridge LLC resonant cell works at fixed switching frequency as a DC transformer with desired performance to realize isolation and main power conversion and an auxiliary full-bridge/push-pull (FB/PP) cell is applied to realize the bipolar voltage regulation and partial power conversion. Two cells share a half-bridge switches branch. Compared with the traditional unipolar voltage regulation PPC, the power processed by dc-dc cell can be further reduced. Finally, the feasibility and advantage verified by simulation results.