Hybrid Structure for an Input-Parallel Output-Serial DC-DC Combined Converter with High Efficiency and High Power Density

Modular input-parallel output-serial (IPOS) DC-DC converter is becoming significantly crucial for high-voltage and high-power applications. However, it requires high efficiency and high power density for further development. For this purpose, an LLC resonant converter with a 1:1 turns ratio transformer is adopted as the basic module in this paper. It utilizes soft switching to realize high efficiency. Besides, the converter uses one module cascaded an input buck converter to achieve output voltage regulation. Moreover, a hybrid interleaved structure design is proposed to reduce the capacitance value significantly. Based on these, an 80kW, 800V (input), 3-3.6kV (output) IPOS converter is designed, which is validated the high efficiency through simulation.