随着新能源技术、输电技术和电力电子技术的发展，大量电力电子换流器接入电网，怎样快速有效地评估系统的暂态稳定性将成为电力系统安全稳定运行的重要问题之一。本项目以换流器共性特征为基础，深入研究考虑换流器动态的电力系统数学模型、暂态稳定机理和基于能量函数的稳定分析方法。内容包括：首先，通过建立含换流器电力系统暂态模型，分析换流器动态与电力系统机电暂态的时标差异，揭示换流器动态影响稳定域及稳定边界的机理。其次，提出一种针对该类系统的能量函数构造方法及其理论基础，并提出基于时标分解模型的逸出点和CUEP计算方法—双时标直接法。在此基础上确定系统的临界能量，阐释失稳机理，定量计算稳定裕度、灵敏度指标和极限参数，提出预防和紧急控制措施。最后，通过实际电力系统稳定评估来检验方法的有效性。本项研究解决含换流器电力系统直接法暂态稳定分析的关键问题，对发展电力系统动态安全评估技术具有重要的理论意义和应用价值。

With the development of new energy technology, power transmission technology and power electronic tehnology, more power electronic converters are connected to the grid, which makes transient stability assessment of such power system one of the essential issues to ensure system safety. It is proposed to consider the common features of converters and investigate the stability mechanism and analysis method. The main work includes the following. First, through constructing the transient stability model of power system with converters, analyze the difference of timescale between the dynamics of converters and electromechanical transients of the system, disclose the mechanism of how the converter dynamics affect the stability region and its boundary. Second, propose an energy function construction approach as well as the theoretical fundation for such kind of power system, determine the exit point and controlling unstable equillibrium point based on the timescale-decomposed model, so as to determine the critical energy, critical parameters and stability margin and further propose the protective and the emergent control strategies. Finally, evaluate the method in practical power system. This proposal aims to implement the application of direct method in power system with converters. It is beneficial to promoting the technology of transient stability assessment, in sense of both theory and application.