This paper details a novel control method designed to diminish peak and rms resonant currents in the resonant tank of proposed half-bridge two-LLC resonant converter, operating across an extensive voltage range. This converter incorporates with different resonant tanks, one operating at the fundamental frequency and the other at three times the fundamental frequency. To accomplish the objective, the study adopts phase shift control to effectively regulate the switches in the two half bridges to achieve in-phase alignment between two currents, optimizing the superimposed current shape. The paper yields a range of merits: (1) reduced rms and peak resonant current while achieving ZVS in all switches on the primary side, leading to further reduced conduction and switching loss; (2) lower circulating energy even with a wide output voltage range; (3) decreased output voltage ripple, which helps to reduce the output capacitance requirement; and (4) simple and straightforward VFM control. The proposed converter outperforms conventional LLC converters with lower current stress and smaller output voltage ripple, which enhances power density.
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