基于端口特性的变流器构网能力评估：构网指数及其动强度贡献
Port-Based Assessment of Converter Grid-Forming Capability: Grid-Forming Index and Contribution to System Strength
罗梁骁 1庄可好 1王康 2陈航宇 1李力 2黄林彬 1辛焕海1
作者信息
- 1. 浙江大学电气工程学院
- 2. 国网陕西电力公司电力调度中心
- 折叠
摘要
随着新能源发电和电力电子装备渗透率提高，电力系统电压和频率支撑能力相对减弱，系统安全稳定运行对电力电子装备的构网和支撑能力提出了更高要求。现有标准和研究将自主构建并维持内电势、呈现电压源外特性作为构网型变流器的核心特征，但现有方法和指标尚难兼顾设备端口特性的可测性、不同设备间的可比性以及系统强度贡献的可解释性。为此，本文从小扰动系统强度出发，提出面向工程测试和控制设计的变流器构网能力评估方法。首先，基于闭环系统电流扰动到母线电压响应的灵敏度矩阵范数表征系统动强度，明确构网型变流器作为“强度源”提升系统抗扰能力的机理；其次，定义构网指数（Grid-Forming Index，FI）和电压源指数（Voltage Source Index，VI），以端口电压对电网电压扰动的灵敏度峰值量化设备电压源特性，并证明FI(jω)<1是设备接入后提高电网强度和系统强度下界的充分条件；进一步，给出基于端口扫频/阻抗测量的工程计算流程，并以导纳整形方法说明FI可用于跟网型变流器构网化设计。最后，通过IEEE 39节点系统仿真验证所提指标与设备动态支撑效果的一致性。
Abstract
High penetration of renewable generation weakens the disturbance withstand capability of power systems, creating an urgent need for quantifiable and testable grid-forming support from converter-based equipment. Existing standards and studies identify autonomous internal voltage and voltage-source terminal behavior as key features of grid-forming converters, but a unified metric that links device-level terminal behavior with system-strength contribution is still lacking. This paper proposes a small-signal evaluation method for converter grid-forming capability from a system-strength perspective. First, dynamic system strength is characterized by the norm of the sensitivity matrix from current disturbances to bus-voltage responses, which clarifies the mechanism by which grid-forming converters act as strength sources. Then, a Grid-Forming Index (FI) and a Voltage Source Index (VI) are defined to quantify voltage-source characteristics through the peak sensitivity from grid-voltage disturbances to converter terminal voltage. It is proved that a device satisfying FI < 1 can improve grid strength and the lower bound of system strength. A practical calculation procedure based on terminal frequency-sweep/impedance measurement is further provided, and admittance shaping is used to show how FI can guide grid-forming-oriented design of PLL-based converters. Simulations on the IEEE 39-bus system verify the consistency between the proposed indices and the dynamic support effect of different devices.关键词
构网型变流器/系统强度/构网指数/电压源指数/端口阻抗测量/导纳整形Key words
grid-forming converter/system strength/grid-Forming Index/Voltage Source Index/terminal impedance measurement/admittance shaping引用本文复制引用
罗梁骁,庄可好,王康,陈航宇,李力,黄林彬,辛焕海.基于端口特性的变流器构网能力评估：构网指数及其动强度贡献[EB/OL].(2026-11-08)[2026-11-11].https://chinaxiv.org/abs/202608.00108.学科分类
输配电工程/电工基础理论
