Single-phase reclosing technique for reducing islanding events of distributed generators during temporary faults

摘要

Integration of renewable energy sources into a distribution system requires adjustments and improvement of the existing relay protection systems. Application of the three-phase reclosing in radial distribution networks often leads to the island operation of the distributed power generation, which causes the generator's disconnection from the network. The application of the upgraded single-phase reclosing technique, which is proposed in this paper, enables a partial transfer of energy into the electric power system during the temporary fault. Thus, it contributes to the maintenance of the distributed generator transient stability during temporary faults in the distribution network. Improvement of single-phase reclosing technique is reflected in the adaptation to eliminate various types of faults that may occur. The analyses include different operation conditions and stability requirements of distributed generators. The proposed solution is presented in the paper by example of different types of distributed generation: a small hydropower plant with a synchronous generator that is directly connected to the distribution network, and a wind power plant with double fed induction generator and photovoltaic systems. The results of the analyses are presented in the form of dynamic simulations performed by DIgSILENT PowerFactory software using IEEE 33-bus model of distribution network.