Robust digital relaying scheme to prevent the miscoordination of recloser-fuse in distributed generation

Power distribution network have a critical issue when distribution generations are integrated to Distribution Network (DN). Miscoordination problem occur between fuse and recloser with presence of DGs. This paper present a new robust digital relaying scheme which is founded on calculation of the fraction of feeder current and recloser current. Using this scheme, frequently modify the time dial setting (TDS) of the protective relay and from now improve margin between fuse and recloser characteristics to eliminate mis-coordination between fuse and recloser. This scheme has been tried for radial distribution network with various types of uncertainties like LG, LL, LLG, LLLG faults. Fault data are obtained from modeling an existing network of 11kV Indian power radial distributed network using PSCAD/EMTDC software package. Moreover it has been observed that the scheme keeps proper coordination between fuse-recloser for all forms of fault and different DG capacities. It is also maintain agreeable operation when high resistance for single line to ground (LG) fault.