Stability Criterion for Near-Area Grid-Forming Converters Under the Weak Grid Condition

作者：Peng Wang, Junpeng Ma, Rui Zhang, Shunliang Wang, Tianqi Liu, Yun Yang · 发表于：IEEE Transactions on Power Electronics · 年份：2024 · DOI：10.1109/tpel.2024.3457892 · 被引用次数：10 · 研究领域：High-Voltage Power Transmission Systems、HVDC Systems and Fault Protection、Power Systems and Renewable Energy

This article introduces a streamlined stability criterion to systematically examine the interaction mechanisms among grid-forming wind turbine generators (GFM-WTGs), particularly within the same wind farm. To elucidate the interaction mechanisms among multiple GFM-WTGs operating under identical conditions and controller parameters, the concepts of common-mode and differential-mode currents, voltages, and impedances, which significantly simplifies the stability criterion, are presented in this article. Since the internal dyanmics of the machine-side converter of GFM-based permanent magnet synchronous generator are disragraded, GFM-WTG is simplified as GFM-based voltage source inverter (GFM-VSI) without losing generality. The stability criterion reveals the characteristics of common-mode and differential-mode currents, allowing for the identification of the dominant factors contributing to system instability. Besides, the influence of connection strengths between GFM-VSI and controller parameters on system stability is examined. Both hardware-in-the-loop and physical experiments based on two paralleled GFM-VSIs validate the effectiveness of the proposed stability criterion.