A Boost-Type Wide Input Voltage Range LLC Resonant Converter

Compared to conventional variable-frequencycontrolled LLCs, fixed-frequency phase-shifting controlled LLCs offer a wider input voltage range under varying voltages. This paper proposes a boost-type LLC with a wide input range using this control strategy, enhancing gain adjustment flexibility and input range. First, its operational principle is presented. Then, gain characteristics are compared with conventional variable-frequency-controlled LLCs to validate superior performance. Finally, a $35 \sim 120 \mathrm{~V}$ input $/ 24 \mathrm{~V}$ output prototype is simulated in MATLAB, with results validating its practicality and theoretical correctness.