Farzad Fallahi - dept of Electrical EngineeringShahid Rajaee Teacher Training UniversityTehran, Iran
Ali Zanganeh - dept of Electrical EngineeringShahid Rajaee Teacher Training UniversityTehran, Iran
Peyman Naderi - dept of Electrical EngineeringShahid Rajaee Teacher Training UniversityTehran, Iran

Distributed generators contribute substantially to thefault currents and thereby upsetting the coordination betweenprotective devices which might lead to fuse blowing or violating thefuse-saving principle. In this paper a novel hybrid algorithm ispresented to mitigate the miscoordination problem after theincreasing penetration of distributed generations in distributionsystems. The mentioned algorithm is based on the classification ofeach pair of fuse and recloser and find the critical point as acoordination index for each classification. In every singleclassification, the fuse current is calculated at the operating point andis compared to the current of the critical point. If the fuse current ispositioned on the right side of the critical point current, thecoordination between the recloser and fuse is lost and some measureslike updating the TDS must be taken which are explained further inthis research. The merits of the proposed algorithm in giving moredesirable results are discussed and the comparison between theproposed algorithm and previous works is made. The algorithm isimplemented on the IEEE ۳۰-bus test system in DIgSILENTpowerfactory and the proposed algorithm is verified anddemonstrated in practice

protection coordination, distributed generation, faultcurrent, recloser, and fuse, Time Dial Setting (TDS)