**6. Conclusions**

A comprehensive review of various protection methods as applicable to micro grid protection is presented. DERs are becoming an integral part of distribution systems but the adequate changes necessary in the protection system has not yet picked up the pace. Lot of research is going on in this area to use the existing protective infrastructure justifiably without compromising on the safety aspect. It is apparent that well-built communication infrastructure is essential for meeting the requirement of micro grid protection. It is due to the fact that there are inevitable topological changes in the network due to the transition of micro grid operating mode from grid connected to islanded and vice versa. Also, the intermittent nature of the DER output and the fault limiting features of inverter fed DGs present several technical challenges to the micro grid protection engineers. Making the protective system to be adaptive is the need of the hour. But it involves lot of infrastructure development and is costly. Many methods based on directional O/C relays, distance relays and voltage based protection schemes have been proposed for effective implementation. However, effective utilization of the existing protective systems with minimal changes in the infrastructure appears to be possible with differential protection scheme. With the advancements in communication technology, micro grid protection can be made adaptive in a cost effective manner.

*Micro-Grids - Applications, Operation, Control and Protection*
