数字控制变流器的准解析大信号建模方法研究

非线性大信号模型对分析数字控制变流器全局动态特性和失稳机理有着重要意义。针对在精确保持系统大信号动力学行为特征的情况下，如何将详细开关模型进行等效化简并构造大信号等效电路这一关键难题，提出以Lie代数理论为依据的大信号建模新思路。重点研究内容如下：①系统推导大信号离散迭代模型，并构建等效电路，为数字控制变流器的大信号建模提供新方法；②探索暂态和稳态下模型与实际系统轨迹充分逼近的参数依赖特性，揭示误差分布规律，为综合评价模型等效性能提供量化指标。③结合模型提取表征系统动态特性的参数，揭示多个参数之间的内在关联和相互作用规律；分析在复杂变流系统中表征参数的相互作用对于整体系统稳定性的影响，为运行特性分析和控制设计提供新手段。本项目的开展，将为解决我国功率变换系统稳定性分析与控制中的共性科学问题提供理论基础。相关研究成果将形成自主知识产权的发明专利，提升我国在该领域的国际竞争力。

Nonlinear large signal model has important significance for global dynamic characteristics and instability mechanism analysis of digital control converter. By precisely maintaining the dynamic behavior under the large signal condition, how to equivalently describe the detailed switching model and construct the equivalent circuit of large signal, is taken as one of the most significant challenges in the power electronics research area. A novel large signal modeling method based on the theory of Lie algebra, is proposed in this proposal. The following major contents are planned to be studied: (1) The iterative model in discrete domain for the digitally controlled power converters will be systematically built, meanwhile the corresponding equivalent circuit model will be constructed, which could provide the advanced technique for the large signal model of the power converters. (2) The parameter dependency characteristic of the fully response approximation between the model and real circuit both under the transient and steady state will be explored, and the error distribution law will be disclosed. A systematic evaluation methodology for the model equivalence criterion will be revealed. (3)The parameter representing the dynamic characteristic of the power converter based on the proposed model will be extracted. The inherent relationship between different parameters will be revealed. The impact of the interaction among the extracted parameters on the complicated power conversion system will be analyzed. The novel approach for the operating characteristic analysis and control design will be achieved. One of the major contributions of this project is to provide the advanced technology for the stability analysis and control design of the power converter system. In addition, some key intellectual properties can be applied to enhance the international competitiveness of China in this area.