Coordination of protective relays for the protection of micro-grid

For effective and efficient use of distributed generation (DG) for consumer at remote areas, the idea of micro-grid has been put forward. Micro-grid (MG) provides mobility to customer; dependability of conventional grid is reduced or even removed after successful implementation of DGs. The reliability can be further improved by forming mesh configuration. Since, MG is operated under grid-connected as well as islanded mode, fault current is extensively different for both the mode of operation. Hence, protection is to be provided for such distribution network is one of the most challenging tasks. Here, analysis is done on Unsymmetrical faults (i.e. L-G, L-L-G, L-L) and the behavior of relays after occurrence of faults. Out of various protective schemes, coordination of instantaneous over-current relay (IOC) and inverse definite minimum time relay (IDMT) are used for analysis under different fault conditions. After clearing of fault the system has to regain its normal operating condition. The simulation is performed using MATLAB/SIMULINK environment. Micro-turbine is used as DG.