IEC TR 63401-2:20 22是一份技术报告，涵盖了转换器接口发电机（例如风力和光伏）中的“控制相互作用”，由此产生的振荡频率低于系统频率的两倍。SSCI可分为: 1）DFIG中的SSCI是由DFIG风力发电机变流器控制与串联补偿网络之间的相互作用引起的。 2）涉及FSC（4型风力涡轮机或光伏发电机）的SSCI是由风力涡轮机或太阳能光伏的FSC控制与弱交流电网之间的相互作用引起的。 本技术报告分为九个条款。第1条简要介绍并强调了本文件的范围。第4条介绍了各种类型的次同步振荡（SSO）的历史背景，并在经典SSR和新出现的SSCI问题的背景下重新审视了术语、定义和分类，以更好地理解和分类新出现的相互作用现象。条款5提供了真实事件框架中SSCI现象的描述、机制和特征，包括ERCOT、固原和哈密风电系统中的SSCI事件。第6条提出了两个基准模型来研究基于SSCI DFIG和FSC的风力涡轮机或光伏发电机。第7条概述了研究SSCI现象的现有和新兴建模和稳定性分析方法。条款8概述了减轻SSCI的各种技术。它讨论了各种SSCI缓解方案，如旁路串联电容器、WTG、发电机的选择性跳闸和工厂级阻尼控制方案。第9条强调了未来在术语、定义、分类、分析方法、基准模型和缓解方法标准化方面的工作的必要性。

IEC TR 63401-2:2022, which is a technical report, covers the "control interactions" in converter interfaced generators e.g, wind and PV with the frequency of the resulting oscillation below twice the system frequency. SSCI can be categorized into:
1) SSCI in DFIG is caused by the interaction between DFIG wind turbine converter controls and the series compensated network.
2) SSCI involving FSC (both type-4 wind turbine or PV generators) is caused by the interaction between wind turbine or solar PV's FSC controls and weak AC grid.
This technical report is organized into nine clauses. Clause 1 gives a brief introduction and highlights the scope of this document. Clause 4 presents the historical background of various types of subsynchronous oscillation (SSO) and revisits the terminologies, definitions, and classification in the context of classical SSR and emerging SSCI issues to better understand and classify the emerging interaction phenomena. Clause 5 provides the description, mechanism, and characteristics of the SSCI phenomenon in the framework of real-world incidents, including the SSCI events in the ERCOT, Guyuan, and Hami wind power systems. Clause 6 proposes two benchmark models to study the SSCI DFIG and FSC-based wind turbines or PV generators. Clause 7 gives an overview of existing and emerging modeling and stability analysis approaches to investigate the SSCI phenomenon. Clause 8 outlines various techniques to mitigate the SSCI. It discusses various SSCI mitigation schemes, such as bypassing the series capacitor, selective tripping of WTGs, generator, and plant-level damping control schemes. Clause 9 highlights the need for future works towards standardization of terms, definitions, classification, analysis methods, benchmark models, and mitigation methods.