电力系统自动化2026，Vol.50Issue(10)：101-109,9.DOI:10.7500/AEPS20250513002
基于Floquet定理的构网型柔直系统稳定性分析及附加阻尼策略
Stability Analysis and Additional Damping Strategy for Grid-forming Flexible DC Transmission Systems Based on Floquet Theorem
摘要
Abstract
The grid-forming flexible direct current(DC)converter stations possess the capabilities of dynamic frequency and voltage regulation and active support,as well as favorable resonance stability under weak grid conditions.However,there is still a gap in the research on their small-signal stability under various non-fault and short-circuit fault conditions.This paper focuses on the analysis of linear periodic time-varying modeling and small-signal stability of grid-forming flexible DC transmission systems.Firstly,a nonlinear state space model of the grid-forming flexible DC transmission system is established,and a linear periodic model suitable for small-signal stability analysis is derived through linearization.Then,based on this model and using Floquet theorem,the small-signal stability of the system under various operating conditions with different short-circuit ratios is investigated.Aiming at the resonance risk of the system under low grid impedance,an additional damping strategy is proposed to improve the stability margin of the system.Finally,simulation verification is carried out on the PSCAD/EMTDC platform.The results show that short-circuit faults in the AC grid significantly affect the stability boundary of the differential-mode control parameters,and the impact of three-phase faults is more significant than that of single-phase faults.When the grid-forming flexible DC transmission system is connected to an AC grid with low impedance,there is an obvious resonance risk.Moreover,under fault conditions,the stability deteriorates as the fault severity increases.关键词
构网型控制/柔性直流输电/Floquet定理/故障工况/稳定性/小干扰稳定性/附加阻尼Key words
grid-forming control/flexible direct current(DC)transmission/Floquet theorem/fault condition/stability/small-signal stability/additional damping引用本文复制引用
刘航,林欣,廖芳群,叶柏贤,汪娟娟..基于Floquet定理的构网型柔直系统稳定性分析及附加阻尼策略[J].电力系统自动化,2026,50(10):101-109,9.基金项目
智能电网国家科技重大专项资助项目(2024ZD0800905). This work is supported by Smart Grid-National Science and Technology Major Project of China(No.2024ZD0800905). （2024ZD0800905）
