With the wide spread application of power electronic device

the harmonic pollution and reactive power harm are increasing serious due to nonlinearity of power electronic elements. In this paper

the circuit harmonic current in the power system of electric arc furnace is taken as study object

the Apriori algorithm based on the sequence association rules

the association rule of between harmonic currents is exploited through analysis of sequence data of harmonic current. It is shown by the analysis and verification of the current data collected from the power supply system of electric arc furnace that the method can be able to predict fundamental wave current amplitude in the future time

thus reaching the purpose of predicting the harmonics in the future

suppressing harmonic pollution and harm of reactive power.