As for such problem as voltage fluctuation and flicker

three-phase unbalance and harmonic due to AC arc furnace

the reactive power compensation allocation calculation method with consideration of power quality constraints is proposed and is controlled by joint operation compensation scheme by the use of static var compensator（SVC）and static synchronous compensator（STATCOM）. The data of actual project of certain arc furnace at Hubei Tianmen is taken as reference

corresponding compensation allocation scheme is given respectively in accordance with three sets of different power quality grade requirement

the power supply system model of three-phase arc furnace based on the above compensation scheme is set up

and its simulation and verification are made. It is shown by the simulation result that the proposed reactive power compensation scheme can solve effectively the power quality problem and

on the perquisite of the controlling result

reduce the investment cost of the scheme and improve the economic efficiency of steel enterprise.