Smart control mode selection for proper operation of synchronous distributed generators

Smart control mode selection is a valuable feature for generators supplying loads in micro grids. This is due to the fact that the proper control mode for operation is different when the micro grid is working in parallel with the grid or is in its autonomous operation state. Moreover selecting the proper mode as a master generator or slave generator in multiple Distributed Generator (DG) micro grids is demanding. A discussion on reconnection detection and island merging detection is presented in this paper. Oscillations due to swinging of the generators against each other and response of the system to the virtual voltage source, belonging to the voltage difference at the time of reconnection, are discussed for development of the smart control mode selector relay. Simulation results conform to the usefulness of the selected features. The advantages of this method are its local, low cost implementation and its fast, non-interactive (passive) operation. The developed logic for this relay could be used along with the present islanding detection methods to enable fully functional localized smart control mode selection.