A High Efficiency and High Power Density Integrated Two-Stage DC-DC Converter Based on Bipolar Symmetric Phase Shift Modulation Strategy

The integrated two-stage buck-boost-LLC isolated dc–dc converter is suitable for wide-voltage regulation range, high-frequency and high-efficiency application. However, the choke inductor current of buck-boost stage injecting into LLC stage will cause nonsinusoidal resonant current and asymmetric secondary current under the conventional modulation strategy. This w...