Arc flash analysis of silver springs north switchyard — A case study in North Florida

Arc flash hazard analysis is required in power systems to protect personnel from the possibility of being injured in an arc flash event. This paper presents the outcome of a full power system analysis project and an arc flash hazard assessment performed by Phasor Engineering prepared for Seminole Electric Cooperatives, Inc. (SECI). The case study of this project is Silver Springs North (SSN) Substation located in North Florida. The electrical power system model of the substation is prepared and analyzed using the Electrical Transients Analyzer Program software, version ETAP 14.1. This substation is fed from two sources: (1): the utility grid as the main source; and (2) a Liquid Propane Vapor (LPV) generator as the emergency back-up source. Control House #2 of SSN contains four main AC Panels. While analyzing the system with the emergency back-up source, it is observed that the protective devices are not able to quickly clear the fault at the location of AC Panels leading to high incident energies. A comprehensive analysis is provided by Phasor Engineering in this project to: (1) recognize the reasons for the high energy levels; and, most importantly, (2) to propose a solution in order to resolve the high incident energy challenge when the substation is fed by the back-up source.