A DC power supply using flying-capacitor three-level PFC and LLC resonant three-level DC/DC converter for wide input-voltage range and multi output

In this paper, a DC power supply for wide input-voltage range and multi output, which is applied to both 200-V and 400-V power sources, is proposed. This power supply consists of a flying-capacitor three-level PFC and a LLC resonant three-level DC/DC converter. In the PFC, the circuit topology enables to use 600-V devices, minimize the detection circuit and the gate drive circuit, and reduce the size of the AC inductor. In addition, 600-V devices are adopted by the three-level topology in the DC/DC converter. The multi output consists of triple 24-V outputs and single 12-V output. The performance of the proposed DC power supply is evaluated by the experiment. The experimental results show that the efficiency reaches more than 88% at both AC 200-V and 400-V inputs. This efficiency is quite high for DC power supplies with wide input-voltage range and multi output.