Detecting the anti-islanding protection based on combined changes of active and reactive output powers of distributed generations

Nowadays renewable energies have taken special place in the world, and most of the distributed generations (DGs) in the power systems utilize these types of energy resources. Due to the DG´s advantages, including using of renewable energy which does not polluting environment and having endless nature, the use of these resources to produce electrical energy in the world are increasing. One problem with such generators is an unwanted islanding phenomenon. In this paper, a new passive method to identify islanding states has been proposed. This method is efficient for both connecting DGs to the network with or without inverter. Since this method is a hybrid method of previous methods, it has better performance than that of the previous methods. Simulation results which are carried out on MATLAB environment, show good performance of this method.