Effectiveness of hybrid differential-adaptive overcurrent protection scheme for microgrid

Abstract

To cope with the significant changes in microgrid short circuit (SC) fault current characteristics caused by switching among grid & islanded operational modes, the said article proposes a new Adaptive Overcurrent Relays Protection (AOCRP) & Differential Relays Protection (DRP) arrangement. To minimize construction upgrade prerequisites and set computational burden, the scheme proposes utilizing AOCRP to protect distributed generators (DGs) as well as individual load points (LPs) and DRP to protect feeders, the backbone of feeders, lines, and buses. This protection scheme is useful to protect the microgrid system in both grid-connected as well as in islanded modes of operation from a large amount of 3 phase SC symmetrical faults like LLL, LLLG, etc.By combining the AOCRP and DRP strategies, this suggested methodology enhances the general reliability, efficiency, power quality, as well as stability of the microgrid. The AOCRP arrangement can be used for faults outside the zone of protection in this article, while the DRP scheme is used for faults within the protected zone. Multiple time-domain simulation models for verification purposes have been performed in the context of this article to determine the effectiveness of the suggested scheme in defending a microgrid infrastructure whereas the operating in grid or islanded modes.