基于部分能量调节的LLC谐振变流器并联均流技术研究

LLC谐振变流器以其优良的软开关性能得到广泛应用，在数据中心等大功率场合，需要将LLC多相交错并联以满足大电流需求。由于谐振变流器采用频率调制，在多相交错并联时均流控制和电压调制之间存在不可调和的矛盾。已有的无源和有源均流方法受到模块扩展性、采样速率和效率的制约，很难实现高频场合下多模块的灵活扩展。.本项目将部分能量调节思路引入LLC谐振变流器多相均流，在保证高效率的前提下实现任意多相LLC模块的交错并联均流。本项目研究部分能量调节的LLC谐振变流器均流方法及拓扑构造规律，优选出高效率、可交错并联、可高频工作的系列拓扑；研究基于部分能量调节系列拓扑的效率优化，得到关键电路参数的设计方法和优化控制策略；研究“调频+调占空比”双重控制策略和模块化并联框架，实现高效率LLC谐振变流器的多模块并联均流。本项目有望为数据中心服务器电源等大电流场合的高效率并联扩容应用提供技术支持。

LLC resonant converter is widely used for its excellent soft switching performance. In many high-power applications, such as data center power supplies, multi-phase interleaved LLC is required to meet the high current requirements. Since frequency modulation is adopted for resonant converter, there is an irreconcilable contradiction between current sharing control and voltage modulation when multiphase is interleaved. Existing passive and active current sharing methods are limited by module scalability, sampling rate and efficiency, and they are difficult to achieve flexible multi-phase expansion in high-frequency applications..This project introduces the partial energy regulation method into the current sharing control of LLC resonant converter, and realizes the current sharing of multi-phase LLC modules on the premise of high efficiency. Based on the partial energy regulation concept, this project studies the LLC current sharing method and topology deduction principles, and selects a series of topologies with high efficiency, interleaved parallel connection and high frequency operation; studies the efficiency optimization of the partial energy regulation topologies, and obtains the design method of key components and optimal control strategy; studies "frequency modulation + duty cycle adjustment" dual control strategy and modular parallel framework to achieve the current sharing for high-efficiency paralleled LLC resonant converters. This project is expected to provide technical support for high efficiency parallel expansion in high-current applications such as data center power supplies.