多端口直流变换器不仅承担着能量的双向转换作用，而且对能量传递实现智能、灵活控制起着极其关键性支撑作用，其运行状况直接关乎到整个系统的工作性能。然而，正由于其内在的强非线性耦合效应，赋予了多端口直流变换器诸多“难以驾御”的特征：更强的非线性、更高的状态与参数空间维数、更复杂的运行模式，对其运行特性产生了巨大影响。要分析这种影响则对传统的理论与方法提出了极大的挑战。本项目通过非线性模态分析方法，研究多端口直流变换器非线性耦合效应的动力学机制；揭示不同运行模式下瞬态扰动机理与传播规律，探究扰动行为对系统安全运行的影响；发展多端口直流变换器多参数稳定性理论方法，分析内外参数关联机制对稳定性的影响，确立系统核心关联参数稳定域；寻求扰动传播与危险潜电路之间的规律，剔除危险潜电路。这些研究都必将对多端口直流变换器综合设计产生深远影响，对确保系统稳定、可靠、优化运行具有十分重要的意义。

How Multi-port DC-DC Converter (MPC) operate is of great significance to the performance of the overall supply system. However, due to the existence of nonlinear coupling effect, MPC have plenty of novel characteristics, which have a great deal of effect on their dynamical behaviors. This will lead to rising to the great challenge of traditional theory and analysis method. In this project, based on nonlinear modular analysis approach, the mechanism of nonlinear coupling effect in MPC is analyzed, complex transient behaviors and their evolution of MPC is revealed under the conditions of large perturbations in order to exploit the applications of the complex perturbation behavior method to some actual engineerings. Moreover, multi-parameter stability analysis of MPC is discussed in detail, and some stable domains of system associated parameters are given so that some related theories and methods are further developed. Finally, a systematic method is proposed to identify potential circuit of MPC in order to ensure the reliability of MPC under three operations. These results will affect the design of MPC, and are of great importance to ensure the stable, reliable and optimal operations of MPC.