超高频功率变换器拓扑及其控制关键技术研究

Very high frequency DC/DC power converters exist some common problems, such as high voltage stress of semiconductors, narrow operating range with high efficiency, great losses of driving circuit, and serious effects of system parasitic components. To solve the above problems, this project will do research on topologies, driving circuits, components design and layout of very high frequency converters. Firstly, based on injection of optimal harmonics, unified design and formation rules of inverter stage and rectifier stage with low voltage stress will be proposed, and the optimal circuits and design methods of matching networks with resistive transferring characteristics will be also investigated; secondly, high efficiency multi-resonant driving circuits will be proposed, and the voltage feedback networks and control methods which satisfy the requirements of self-resonant driving circuits will be also investigated, thirdly, design methods of magnetic components with high quality factor will be proposed, and the optimal system layouts with small parasitic components will be also studied. In the project, experimental platform will be built to verify the correctness and the validity of topologies, driving circuits, components design and layout methods. The achievements of this project will provide theoretical basis and technical support for very high frequency converters applied in low level power transferring fields.

超高频DC/DC功率变换器存在半导体器件电压应力过高、拓扑高效工作范围窄、驱动系统效率低以及系统寄生参数影响大等共性问题。为解决上述问题，本项目将围绕超高频功率变换器拓扑、驱动、系统元件设计和布局等方面展开研究工作。首先，采用谐波优化的方法，提出低电压应力型谐振逆变与整流环节统一设计规则并研究其运行机理，同时探索宽范围阻性传输特性匹配网络拓扑结构及其优化设计方法；其次，提出高效多谐振驱动网络，探究满足自谐振驱动需求的电压反馈网络及其控制方法；最后，研究高品质因数磁性元件设计方法和低寄生参数元件布局方法。本项目将通过搭建超高频功率变换实验平台来验证所提谐振拓扑结构、驱动电路结构、元件设计和布局方法的正确性。本项目的研究成果将为超高频功率变换器在小功率电能变换领域中的应用提供理论依据与技术支撑。

针对超高频功率变换器逆变与整流环节半导体器件电压应力高的问题，研究低电压应力型超高频逆变与整流拓扑，拓宽超高频功率变换器输入、输出电压范围。改进现有匹配网络传输特性，在宽负载变化范围内保持开关管的软开关特性。研究超高频多谐振及自谐振驱动网络设计准则及高效系统控制策略。研究超高频条件下高品质因数磁性元件设计方法，探究系统元件优化布局方法及寄生参数利用方法。围绕：宽范围高效超高频功率变换器拓扑结构及运行机理；超高频功率变换器寄的高效驱动与控制策略；超高频功率变换器系统元件设计展开研究，取得成果包括（1）提出了非隔离型超高频功率变换拓扑，通过谐振整流、逆变环节的精准建模及多种形式匹配网络的优化设计，有效提高系统效率及高效运行范围。（2）提出了低电压应力隔离型超高频功率变换拓扑，利用变压器的漏感及寄生电感，通过在开关管漏源极两端引入三次谐波，实现了低电压应力的软开关超高频拓扑。（3）针对超高频功率变换器中的核心元件—超高频磁性元件提出了优化设计方法，通过绕组宽度的精准调节，可有效减小交流直流电阻，有效提高系统效率。（4）提出了高效谐振驱动及自谐振驱动方法，实现超高频条件下高效可靠驱动。基于上述研究内容，发表SCI/EI论文18篇，授权发明专利6项，培养博士生1名、硕士生11名。