Autonomous Seamless Transition between Grid-Connected and Islanded Operations for DC-Coupled EV Charging Infrastructures

Karaki A., Sharida A., Bayhan S., Abu-Rub H.

IEEE Open Journal of the Industrial Electronics Society, cilt.7, ss.951-963, 2026 (ESCI, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 7
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1109/ojies.2026.3697995
  • Dergi Adı: IEEE Open Journal of the Industrial Electronics Society
  • Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus, Compendex, INSPEC, Directory of Open Access Journals
  • Sayfa Sayıları: ss.951-963
  • Anahtar Kelimeler: Adaptive grid synchronization, grid-forming (GFM) electric vehicles (EVs), seamless transition
  • Gazi Üniversitesi Adresli: Evet

Özet

This paper proposes a novel seamless transition technique between grid-connected and islanded operations for DC-coupled electric vehicle (EV) charging infrastructures. The main objective of the proposed approach is to ensure that the critical grid and EV requirements will be satisfied during the transition, including frequency, rate of change of frequency (RoCoF), current, rate of change of current (didt), and voltage ride-through requirements. The proposed approach provides three main functionalities, the first one is to ensure the seamless transition between islanded to on-grid operation, the second one is to control the transition process from grid-connected to islanded operation (intentional islanding), while the third one is to perform a fast transition to grid-forming (GFM) operation when the utility grid is suddenly disconnected (unintentional outage). The algorithm is primarily based on trajectory-based frequency control to synchronize the charging infrastructure with the grid while adhering to RoCoF constraints. Moreover, the reference currents are adaptively generated to ensure a smooth transition, effectively controlling transient currents by minimizing overshoots and limiting didt. This approach mitigates surge power and prevents false tripping of the protection system while maintaining stable operation during dynamic conditions. The effectiveness of the proposed technique is validated experimentally.