Islanding Detection and Resynchronization with Anti-Islanding in Distributed Generation

The growing uses of distributed generation (DG), the exploitation of renewable energy, and the adoption of the microgrid concept have changed the structure of traditional electric power networks. By constructing a microgrid, the majority of new power system networks are shifting to the DG model combined with renewable and nonrenewable energy resources. Islanding detection in systems is a complicated issue that generates multiple protection and safety issues. This paper proposed an efficient way of fault detection by using a S-R flip-flop relay. Anti-islanding protection method is developed for resynchronization of the system with the grid. The proposed S-R flip-flop relay is used as a switch to disconnect the load from the grid instantly. The systems operate in constant current mode under normal conditions and after being islanded it transfer to voltage control mode. The proposed model is based on passive method (local detection technique) that is carried out for Under/ Over voltage, Under/ Over Frequency, Rate of change of frequency (ROCOF). This concept's implementation is validated using MATLAB/SIMULINK software.