A data driven based adaptive unit protection for transmission line integrated with large penetrated wind farms

• Published in: Electric power systems research 2023-11, Vol.224, p.109732, Article 109732
• Main Authors: Ansari, Md Kaisar Azam, Nema, Savita
• Format: Article
• Language: English
• Subjects: Euclidian distance; Large scale offshore wind farms; Pilot relaying; Short-term matrix pencil; Transmission line
• ISSN: 0378-7796
• DOI: 10.1016/j.epsr.2023.109732

•Unit protection for DFIG based wind farm equipped transmission lines irrespective of penetration level.•Derivative based Euclidian distance of reconstructed differential current.•Reconstruction using short term Matrix pencil based method.•Decision based on adaptive threshold value.•Exhibits low computational burden. The dynamic fault current characteristics, transient behaviour, and changing output power of large-scale doubly fed induction generator-based wind farms (WFs) have severe influence on transmission line conventional current differential schemes. Under normal conditions, the current difference between two ends of transmission line grows as its length increases. The capacitive charging current then might equal load current if power output of WF is low. In the presence of WFs, Traditional differential protection techniques are experiencing challenges. In order to ascertain the possible impacts of various scenarios with substantial offshore wind farms connected to transmission lines on differential relay characteristics, a data-driven approach is proposed in this paper. The STMPM based signal reconstruction method is used to compute the per-phase differential current and then their first and second-order derivatives are estimated to find the net change in the current magnitude. Finally, the Euclidean distance between these first and second derivative components are calculated and employed as a disturbance detection index (DDI). The conducted PSCAD/EMTDC simulation studies demonstrate satisfactory operation of proposed startergy for a wide range of disturbances, including external and internal faults, fault resistance, variable fault location, change in WF penetration, and various kinds of non-fault switching events.