This article presents a control strategy to mitigate subsynchronous control interactions in doubly-fed induction generator (DFIG)-based wind farms. The strategy makes use of a multi-terminal dc (MTDC) system to damp subsynchronous oscillations (SSOs) by adding a supplementary damping control (SDC) to MTDC grid converters. The SDC is focused on stations with modular multilevel converters. This converter topology currently allows the integration of several high-voltage and high-power MTDC applications into modern power systems. Additionally, the case in which SDCs are added to both MTDC grid converters and DFIG converters is analyzed. The SDC is designed using an identified model of the system. The identification method injects probing signals from the converter terminals and obtains an identified model by measuring the response of the system. This method facilitates the control tuning and implementation of the SDC in practical systems in which either the equations and parameters of some equipment can be difficult to know precisely or the model of commercial equipment is not available.

中文翻译：

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使用多端子DC系统缓解次同步控制相互作用

本文提出了一种控制策略，以减轻基于双馈感应发电机（DFIG）的风电场中的次同步控制相互作用。该策略利用多端子直流（MTDC）系统，通过向MTDC电网转换器添加辅助阻尼控制（SDC）来阻尼次同步振荡（SSO）。SDC专注于带有模块化多电平转换器的站。该转换器拓扑当前允许将多个高压和大功率MTDC应用集成到现代电源系统中。此外，分析了将SDC添加到MTDC电网转换器和DFIG转换器的情况。使用确定的系统模型设计SDC。识别方法从转换器端子注入探测信号，并通过测量系统的响应来获得识别的模型。