This article is introducing a new controlling scheme for islanding operating of inverter-based distributed generations. That in this method load protection at the time of connection to the network and islanding operation is completely intended. Moreover, the islanding detection algorithm which is based on ROCOF relaying, for detecting islanding phenomenon is provided. The algorithm is also equipped with synchronization block that at the time of network retrieval would be able to reconnect the upper network to the distributed generation. It is necessary to mention that all the simulations and tests are carried out in the MATLAB / Simulink environment. Provided method has security and flexibility and will have no interference with operation of voltage regulation instruments in the distribution network.