随着接入电网的可再生能源、储能、电动汽车等规模的进一步扩大，现代电力系统已呈现出电力电子化的趋势，其复杂的动态特性严重影响着电力系统的安全稳定运行。现有的动态建模与分析方法大多基于信号处理的观点，难以表征大扰动下多变流器系统的非线性能量交互机制，因而无法有效地揭示变流器暂态特征对系统稳定性的影响规律。项目拟从能量的观点研究计及交互作用的多变流器系统大信号稳定性分析方法，围绕能量函数方法中多变流器系统位能边界曲面的获取，研究基于端口哈密顿理论的并网变流器系统暂态建模及分析方法。项目利用正交分解和首次积分法构建并网变流器的哈密顿能量函数，建立多变流器系统的端口哈密顿模型；基于耗散原理解析出系统的大信号稳定性判据，并计算系统的稳定参数域及安全运行边界；提出基于能量的无源控制策略，以改善多变流器系统的阻尼特性。项目研究为进一步保障大规模新能源安全可靠地接入电网提供理论支撑。

With more and more renewable energy, energy storage systems and electric vehicles are integrated into the grid, the dynamic characteristics of power-electronics-enabled power systems become much more complicated, which greatly affects the stable and safe operation of modern power systems. However, the previous studies on the modeling and analysis of power converters are mainly oriented from signal-processing perspective, which cannot reveal the intrinsic principle of nonlinear energy interactions between multiple converters under large-signal perturbations. Therefore, the relationships between the transient characteristics and the stability of grid-connected converter systems are still not clear. This project will investigate the large-signal stability of multi-converter systems considering their dynamic interactions from the view point of energy. To acquire the curve boundary of energy functions for multi-converter systems, the nonlinear dynamic model of complex power converter systems are established and analyzed based on Port-Hamilton theory. Firstly, Hamiltonian energy functions are constructed for grid-connected converters, and then Port-Hamilton models of multiple converters are built based on orthogonal decomposition and first integration approaches. Then, according to the dissipative principle, the analytical stability criterion is proposed to calculate the stable parameters space and operation boundary. Finally, passivity-based control strategies are designed for multi-converter systems to achieve damping assignment and energy reshaping. Research founding of this project could provide fundamental theory and application supports for the safe and reliable integration of large-scale renewable energy.