Adaptive Differential Protection System for Microgrid

Abstract

Microgrids are the small version of power system which grants us the integration of distributed generation resources to insure the facilities to the remotely located electric loads as well as have so many advantages over traditional power system like reduced transmission loss, green energy solution and proper use of renewable energy resources. However the resilience offered by microgrid is inconvenient if it is not be able to protect properly in case of any disturbance occurs which is very common in microgrid due to load dynamics. Protective devices used in traditional power grid cannot actually protect microgrid due to variable loads and different fault levels at grid connected modes and islanded modes. The available research about this concern has not been very successful, therefore options like distance, directional over current and differential relay remains effective protection scheme from present standard. Even though these relays are very useful in power system but their effectiveness for microgrid is yet to be analyzed. This paper is presenting the MATLAB simulation based analysis for differential relay type adaptive protection system by taking a complex microgrid model and generating various fault and generation capacities and analyzing it. In this paper different scenarios has been discussed where differential relay seems to be better than distance and directional over current relay protection scheme.