Impact of Distributed Energy Resources on Arc Flash Incident Energy

Electric line personnel perform energized overhead line work and expose themselves to potential arc flash burns. Arc flash incident energy is calculated to determine proper personal protective equipment to protect line personnel against bodily injuries. As increased amount of distributed energy resources (DERs) are being interconnected to distribution systems, higher arc flash incident energy is encountered. This paper explores the arc flash incident energy calculation method for distribution overhead feeders with the presence of DERs. The impact of DERs on arc flash incident energy is evaluated on nine Dominion energy's distribution feeders that interconnect solar inverters. Various factors, including DER mega volt-ampere (MVA) capacity, DER unintentional islanding run-on time, and DER step-up transformer winding configuration are considered. The effectiveness of neutral grounding resistors and low set instantaneous protection is also explored.