Multiphase LLC Resonant Converter With Interleaving, Natural Current-Sharing, and Phase-Shedding

A plethora of research has been conducted on ensuring reliable operation of multiphase LLC resonant converters, particularly addressing the uneven current distribution caused by mismatched circuit parameters. However, most existing solutions achieve current-sharing (CS) and phase-shedding (PS) at the cost of additional components and increased system complexity. This paper proposes a novel interleaved multiphase LLC resonant converter that simultaneously achieves CS, PS, and interleaving without the need for extra components and added cost. This is made possible by a common voltage doubler rectifier (CVDR), which not only reduces the number of voltage-doubler capacitors but also acts as a variable voltage source to ensure excellent CS. Additionally, the CVDR facilitates seamless PS and interleaving operations, leading to enhanced dynamic response, reduced input- output filter capacitances, and improved light-load efficiency. The operating principles of CS and PS are discussed, and a 750 W three -phase hardware prototype is developed to experimentally validate the performance of the proposed multiphase LLC converter.