A Novel LLC Converter with Split Transformers for Output Current Ripple Suppression

A novel LLC converter with split transformers (STs) which can suppress the output current ripple is proposed. By utilizing non-equal-turns-ratios (NET) in two series-connected transformers, distinct magnetizing currents are generated, and then, achieving the suppression of output current ripple which is a significant issue with the conventional LLC converters. The output capacitors can thus be reduced for achieving high power density and it is possible to achieve electrolytic-capacitor-less for improving the system lifespan and reliability. Furthermore, the proposed NET-ST LLC converter also promises high efficiency with zero-voltage switching (ZVS) for the primary-side switches across the entire operating range and zero-current switching (ZCS) for a portion of the secondary-side rectifier diodes.