AI 中文总结
研究电流受限型并网逆变器故障后恢复问题，提出结合结构解耦虚拟导纳电压控制与电流角度控制的故障后恢复框架，可改善同步轨迹演化、稳定恢复边界，实验验证能消除故障后不良转换，实现可靠同步恢复。
AI 中文摘要
随着基于逆变器的资源取代同步发电，电流受限条件下并网逆变器的可靠故障恢复变得越发重要。现有限流策略主要关注电流角度调节和同步轨迹整形，而电流限制器与电压控制结构之间的相互作用仍未得到充分理解，导致故障后恢复可能出现逆变器陷入电流限制控制或在电流限制控制与恒压控制之间振荡转换的情况。本文表明，在传统PI电压控制下，电压控制器与电流限制器之间的相互作用会产生移动恢复边界，导致恢复失败。为解决此问题，提出了一种故障后恢复框架，将结构解耦的虚拟导纳电压控制与电流角度控制相结合。该框架在故障恢复期间同时改善同步轨迹演化并稳定恢复边界。在3kVA并网逆变器原型上的实验验证证实了在对称和不对称电压暂降条件下可靠的故障后同步恢复，消除了陷入和振荡的电流限制控制 - 恒压控制转换。
英文摘要
Reliable fault recovery of grid-forming (GFM) converters under current-limited conditions is increasingly important as inverter-based resources replace synchronous generation. Existing current-limiting strategies primarily focus on current-angle regulation and synchronization trajectory shaping, while the interaction between the current limiter and the voltage control structure remains insufficiently understood. Consequently, post-fault recovery may exhibit converter trapping in current-limited control (CLC) or oscillatory transitions between CLC and constant voltage control (CVC). This paper shows that, under conventional PI-based voltage control, the interaction between the voltage controller and the current limiter creates a moving recovery boundary that contributes to these recovery failures. To address this issue, a post-fault recovery framework is proposed that combines structurally decoupled virtual admittance voltage control with current-angle steering. The proposed framework simultaneously improves synchronization trajectory evolution and stabilizes the recovery boundary during fault recovery. Experimental validation on a 3-kVA GFM inverter prototype confirms reliable post-fault synchronization recovery under both symmetrical and unsymmetrical voltage sag conditions, with trapping and oscillatory CLC-CVC transitions eliminated.
Comments10 pages, 9 figures, 2 tables
