A New Method for Loss Optimization in LLC Resonant Converters via Integrated Magnetic and Tank Design

ABSTRACT In environments with numerous converters, there is a need for highly efficient. The LLC resonant converter is a good candidate for microgrid applications, as it features low switching losses and a wide voltage regulation range. However, designing magnetic components with lower losses remains a challenge for designers. This paper presents a methodology for reducing losses in the LLC resonant converter by integrating the tank design with the construction design of the transformer and resonant inductor. An algorithm generates a list of feasible components, filtered by constraints on flux density, core temperature, inductance, and winding resistance. The filters select resonant tank element designs that operate at the ideal core temperature, with fewer turns, and that limit current circulation. The tank elements were constructed for validation through experimental results on a 1 kW prototype. Experimental results demonstrated a peak efficiency of 97.48% under ideal thermal conditions. Losses in the resonant tank were reduced by 6.6% compared to ambient operation. Further efficiency (up to 97.52%) was achieved by increasing the magnetizing inductance. The results confirm that the integration of the magnetic design with the design of the resonant tank allows the reduction of losses in LLC converters.