【目的】新能源高比例接入背景下，电力系统正加速向电力电子装备主导转型，变流器作为新能源并网的核心接口，其暂态稳定性已成为制约新型电力系统安全运行的关键问题。跟网型（grid-following， GFL）与构网型（grid-forming， GFM）变流器是两类主流并网变流器范式，二者在同步机理、动态特性及失稳机制上存在本质差异。系统梳理两类变流器的暂态稳定机理，对比分析评估方法并归纳稳定性提升策略，对于支撑变流器并网系统安全运行具有重要意义。【方法】基于同步机理与控制结构差异，梳理跟网型锁相环（phase-locked loop， PLL）同步控制与构网型功率同步控制（power synchronization control， PSC）在暂态行为上的核心差异，阐明锁相环动态、等效惯量与阻尼特性、电流限幅等环节对暂态稳定性的影响机理。在此基础上，系统归纳三类暂态稳定分析方法：微分代数方程求解类方法、能量函数类方法以及人工智能类方法，并总结其适用范围、优势与局限。【结果】研究表明：GFL变流器暂态稳定性高度依赖电网强度与扰动强度，弱电网或大扰动下易因PLL失步引发同步故障；GFM变流器能主动构建电压与频率基准，但在多机互联系统中可能因控制耦合呈现更强的非线性特征，且电流限幅环节可能诱发非期望平衡点及模式切换问题。总体而言，当前研究仍存在三方面不足：对强非线性控制下暂态同步失稳机理的揭示仍不充分，适用于电力电子主导系统的暂态稳定判据仍不成熟，多源系统的全局分散协同控制思路仍不清晰。【结论】本文系统总结了含GFL/GFM变流器的并网系统暂态稳定性研究进展，并指出未来研究可重点聚焦：不同运行方式下的暂态稳定机制表征、多机系统耦合机制及暂态稳定判据构建、参数弱依赖的稳定性提升分散协同控制策略、物理机理与数据驱动相结合的评估与控制方法等方向。相关结论可为深化电力电子主导系统暂态稳定性认知、支撑新型电力系统安全运行提供参考。

[Objective] With the increasing penetration of renewable energy， the power system is accelerating its transformation towards being dominated by power electronic equipment. As the core interface for renewable energy grid connection， the transient stability of converter-connected systems has become a critical issue restricting the safe operation of new-type power systems. Grid-following （GFL） and grid-forming （GFM） converters represent two mainstream grid-connected converter paradigms， with fundamental differences in synchronization mechanisms， dynamic characteristics and instability mechanisms. A systematic analysis of their transient stability mechanisms， a comparison of evaluation methods， and a summary of enhancement strategies are essential for ensuring the safe operation of converter grid-connected systems. [Methods] Based on the differences in synchronization mechanisms and control structures， this paper delineates the core differences in transient behaviors between phase-locked loop （PLL） synchronization control for grid-following converters and power synchronization control （PSC） for grid-forming converters. It elucidates the influence mechanisms of PLL dynamics， equivalent inertia and damping characteristics， and current limiting on transient stability. On this basis， three categories of transient stability analysis methods are systematically summarized： methods based on solving differential-algebraic equations， energy function methods， and artificial intelligence methods. Their applicable scopes， advantages and limitations are also concluded. [Results] The research shows that GFL converter transient stability is highly sensitive to grid strength and disturbance intensity， and is prone to synchronization failure due to PLL out-of-step under weak grids or large disturbances； GFM converters can actively provide voltage and frequency references， but exhibit complex nonlinear dynamic characteristics due to control coupling in multi-machine interconnection scenarios， and current limiting may easily induce unexpected equilibrium points and mode-switching problems. In general， current research still suffers from three major shortcomings： insufficient understanding of the mechanism of transient synchronization instability under strongly nonlinear control， the lack of transient stability criteria applicable to power-electronics-dominated systems， and the absence of a global decentralized coordinated control framework for multi-source. [Conclusions] This paper systematically summarizes the research progress in transient stability of grid-connected systems containing GFL/GFM converters， and points out key directions for future research： characterization of transient stability mechanisms under different operating modes， construction of coupling mechanisms and transient stability criteria for multi-machine systems， decentralized coordinated control strategies for stability enhancement with weak parameter dependence， and assessment and control methods combining physical mechanisms with data-driven approaches. These conclusions can provide methodological references and a basis for design， while deepening the understanding of transient stability in power-electronics-dominated systems and supporting the safe operation of new-type power systems.