Arc flashes pose significant hazards to personnel working with energised power lines due to their high thermal risk

quantified by incident energy (IE) in joules or calories per area. Accurate estimation of IE is crucial for ensuring safety. The most widely employed method for estimating IE from an arc flash is outlined in IEEE Std 1584-2018

which applies exclusively to three-phase AC arc flashes. However

limited research has explored alternative methods due to the complexities

costs

and preparation involved. Numerical simulations offer a viable alternative for studying arc flashes. This paper introduces a multiphysics simulation approach for determining IE by modelling three-phase AC arc flashes using the magnetohydrodynamics (MHD) theory. This study exclusively investigates horizontal electrodes in open-air (HOA) configuration due to the specific characteristics of the local power system configuration

which predominantly features overhead power lines

and the available test setup in the laboratory. The IE derived from simulations is compared with measurements from an arc flash laboratory based on IEEE Std 1584-2018 and with the IE calculated by the standard itself. The results indicate a significant alignment between this innovative approach and other methods for estimating IE for three-phase arc flashes.