This paper briefly discusses the challenges related to the Islanding operation in power systems and presents different methods to detect the islanding condition with an example of photovoltaic applications. Furthermore, it proposes a secure method of islanding detection using synchrophasors. The proposed algorithm has been verified with Real Time Digital Simulator (RTDS) tests, as well as in laboratory environment with an inverter connected to grid. With the help of extensive testing, it is demonstrated that the proposed method successfully performs automatic and manual decisions to assure the correct and secure operation of the distribution grid.