A Novel Approach to Tackle Miscoordination of Protective Device in Radial Distribution Network during DG Interconnections

Due to incorporation of Distributed Generation (DG), the traditional protection scheme for electric power distribution system lost its radial nature and behaves more like multifeed transmission system. Hence, there is a need to develop a new protection scheme for electric power distribution system which remains stable in all conditions. This paper presents a new directional protection scheme for distribution system containing DG. Authors have developed a laboratory prototype of the three-phase radial distribution system containing DG. The proposed scheme has also been simulated using the PSCAD/EMTDC software package with fault data generated by modeling the distribution systems. The proposed directional protection scheme has been tested for various types of faults in different sections of radial distribution network along with DG. At the end, a comparative evaluation of the results obtained using the developed laboratory prototype has been carried out with the simulation results obtained using PSCAD. It has been observed that the proposed scheme has the ability to isolate the faulted section without disturbing the healthy section in the presence of DG.