Details

Autor(en) / Beteiligte

• Sanati, Saeed
• Azzouz, Maher

Titel

A new inrush current detection for collector transformers’ differential protection in DFIG-based wind farms

Ist Teil von

• Electric power systems research, 2023-12, Vol.225, p.109766, Article 109766

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The proposed method in the paper offers several key contributions.•Accurate detection of inrush current during the activation of crowbar and DC-link protection schemes in wind farms, specifically addressing the challenges of DFIG-based systems.•Effective differentiation between CT saturation and inrush currents, ensuring reliable detection in various operating conditions.•Utilization of harmonic phase signs (HPSs) for the 1st to 10th harmonics of the collector transformer (CTr) primary current, enabling real-time comparison with a predefined pattern for inrush current detection.•Distinguishing between inrush currents and internal faults of the CTr even during FRT of DFIGs, providing enhanced protection capabilities. As doubly-fed induction generator-based (DFIG-based) wind farms become increasingly widespread, the need for ongoing improvement in their protective studies becomes imperative. This paper focuses on the protection of the collector transformer (CTr), a key component of DFIG-based wind farms. One of the critical requirements for the differential protection of the CTr is the detection of inrush current. However, internal faults in the CTr can lead to harmonic interference and cause false detection of inrush current, resulting in the maloperation of the CTr differential protection. To address this issue, a new harmonic-based method for identifying inrush current in DFIG-based wind farms is introduced. The method is based on analyzing the phase signs of harmonics (HPSs) from the 1st to 10th harmonic. The proposed method ensures the accurate operation of the CTr differential protection and effectively distinguishes inrush currents from internal faults in the CTr. The effectiveness of the proposed method is validated through simulation and experimental results. The proposed method showcases several notable advantages, including precise detection of inrush current during the activation of crowbar and DC-link protection schemes, and effectively distinguishes between CT saturation and genuine inrush currents.