Coupled Dual Interleaved Flyback Converter for High Input Voltage Application

This paper proposes an integrated magnetic DC-DC converter suitable for high input voltage application. The converter is based on a coupled input-series and output-parallel dual interleaved Flyback converter concept. All the center and outer legs are gapped, and the transformers are integrated into one magnetic core with not so tight coupling. The gap is beneficial for suppressing current spike caused by the voltage mismatch between the windings. The two transformers are inversely coupled, and current ripple reduction can be achieved with suitable coupling design. A prototype with 350-450V input and 24V/4A output is built. Experimental results verify the performance of the new topology.