Evaluation of Two Anti-Islanding Schemes for a Radial Distribution System Equipped With Self-Excited Induction Generator Wind Turbines

Local distribution companies (LDCs) require disconnection of distributed generation (DG) as soon as disturbance events occur to prevent sustainable islanding and damaging DGs and other equipments. In this paper, real-time laboratory testings were carried out to evaluate existing anti-islanding detection schemes. A comprehensive analysis and a testing process are proposed to assess the selection of a fast and reliable scheme for a practical radial distribution system equipped with a group of self-excited induction generator wind turbines (SEIG). Two anti-islanding schemes (passive local detection and communication based) were examined on various commercial relays to disconnect SEIG-DG in case of a main breaker opening due to a fault. The impact of existing recloser timer characteristics on the selection of the proper scheme is illustrated. The selected scheme was verified to disconnect SEIG-DGs in case of a manual main breaker opening in a proper time to protect public safety. A dedicated fiber optic connection and radio frequency communication-based schemes were evaluated and compared with passive local detection scheme performance. Various scenarios of SEIG-DG penetration levels were simulated, and different available commercial relay functions were tested. The obtained results, recommendations, and economic evaluations for choosing a proper scheme are reported and discussed.