基于高频变压器隔离的单级式谐振型AC/DC变换器关键技术研究

随着分布式储能、微网和电动汽车与电网(V2G)应用爆发式增长，急迫需求新一代高性能、低成本双向隔离AC/DC变换技术。本申请项目将结合高效率、高可靠和低成本单级变换和谐振软开关优势构建单级式谐振型AC/DC变换方式，然而谐振电路的非线性、谐振腔输入电压的非对称性、以及控制量耦合特性造成该类变换器的分析和控制极其复杂。本申请项目将围绕其原理分析、建模与多变量控制以及应用适应性等关键技术展开探索。1）针对多谐振模态带来的强非线性，提出了采用数值分析方法来研究刻画变换器增益及控制变量和目标间静态特性；2）针对单级式变换多重控制目标，提出了基于多次谐波的扩展描述函数建模方法，推导多变量与多目标之间动态特性及其耦合特性；3）针对宽电压范围应用场合，分别提出了移相控制策略和多谐振电路方式满足宽电压范围应用需求。通过本申请项目的探索，为AC/DC变换提供更优技术方案，同时也将丰富AC/DC变换理论。

With rapid deployments of distributed storage systems, micro-grid and electric vehicle to grid(V2G) applications, it is highly desired for new generation bidirectional isolated AC/DC conversion technology featuring high performance and low cost. The proposal proposed single-stage resonant AC/DC conversion by combining the merits of both the single-stage conversion with high efficiency, high reliability and low cost, and soft switching resulting from resonant operations. However, nonlinearity of resonant circuitry, asymmetry of input voltages to the resonant tank, multi-variable coupling lead to the extreme difficulties on the analysis and control of these kinds of converters. The proposal will carry out the extensive exploration on analysis, modeling, multi-variable control as well as applicability issues of these converters. 1)Due to the strong nonlinearity resulting from multi-mode operations of resonant circuitry, the proposal studies the static characters of converter gain and the mathematical relationships between control variables and their objectives by employing the numerical analysis method ;2) The proposal proposes a modeling method for these kinds of converters based on extended description function with considering both fundamental and several orders of harmonics, and derives the dynamic characteristics between multi-variables and their control objectives, and their coupling relationship; 3)To meet applications with wide voltage ranges, the proposal proposes both phase shift control strategy and multi-resonant tank circuitry. Through the exploration of the proposed project, it would not only offer a better solution to AC/DC conversion but also enrich AC/DC conversion theory.