In view of the series arc fault in the three-phase power consumption system

due to the increase of theasymmetry and high-order harmonics in three-phase currents when the three-phase load has a single-phase arc fault

based on the instantaneous reactive power theory

a fast detection method of series arc fault is presented. And the cal-culation process of extracting the harmonics of three-phase currents is given. The amplitude change times of positiveand negative sequence components of fundamental wave and harmonics in the adjacent two power frequency cycleare taken as the characteristic attribute. Arc fault discrimination rules are constructed by decision tree

and the dis-criminant logic diagram is given. The results show that the method can rapidly and accurately detect the single-phaseseries arc fault in three-phase power consumption system.