Modeling and simulation of an Adaptive Relaying Scheme for a Microgrid

Currently, there has been a significant interest in deployment of renewable and low carbon energy sources in the form of microgrids for local energy generation. Microgrids operate in two modes - stand-alone and grid-connected. This poses a problem in microgrid protection settings in a sense that the fault current magnitude in a microgrid reduces drastically during its transition from grid-connected to stand-alone mode of operation. Adaptive relaying is one solution to this problem where the relay would sense the operating mode and accordingly change its settings to suit the expected fault current magnitudes. This paper demonstrates the development of an Adaptive Relaying Scheme for a Microgrid. This scheme is achieved using intelligent relay models that can detect the mode of operation of the Microgrid. Matlab Simlink is used to develop the relay and power system models. The results show that the relaying scheme adjusts its setting by sensing the mode of operation of the microgrid with very little delay.