适用于宽输出范围的混合控制全桥LLC电路

摘要

A PFM and phase-shift hybrid control strategy for full-bridge LLC resonant converter is introduced in this paper, which applies phase-shift control mode in low voltage output or light load conditions and applies PFM control mode in high voltage output or heavy load conditions and makes LLC’s output characteristics better. And detail analysis of operating conditions for phase-shift control mode, selection of phase-shift frequency and control strategy is presented. A 2.5 kW experimental prototype with 100 V input voltage and 150-550 V output voltage is provided to verify the effectiveness of this hybrid mode control method.%提出了一种针对全桥LLC电路的混合控制方法，在低压低功率情况下采用移相控制，高压高功率情况下采用PFM控制，有效地拓宽了LLC的输出范围。对移相模式下的工况、移相频率的选择及控制方法进行了探讨和研究。搭建了一台2.5 kW、输入100 V、输出150～550 V样机，验证了混合控制方法的可行性和有效性。