Optimization methodology for minimizing the arc flash incident energy

Abstract

In this paper an optimization methodology for minimizing the arc flash incident energy has been presented. Arc flash incident energy for a given system mainly depends on fault current and protective device trip time. Protective device trip time is inversely related to the fault current. Therefore reduction in the fault current may not cause a decrease in the incident energy, because trip time of protective device increases at reduced fault current which consequently may cause an increase in the arc flash incident energy. A methodology has been developed to determine the optimal fault current and trip time for minimizing the arc flash incident energy. Optimal tap and time dial settings of a relay along with optimal fault current were also proposed to further reduce the incident energy. Series reactor sizing to obtain the optimal fault current for minimizing the incident energy was demonstrated as well. The proposed method was tested on a 34.5 kV switchgear at Ronald Reagan Washington National Airport using SKM simulation software.