The static var compensator（SVC） is widely used in the industrial customers such as electrification railway

metallurgy and steel making etc with aim of reducing reactive power impact and voltage fluctuation as well as improving electric power quality.However

considerable electromagnetic interference will be generated by the power electronic devices SVC during the switching process

influencing normal operation of the secondary equipment.The reactive power compensation device of certain rolling mill is taken as an example

the electromagnetic inference level under different conditions on site are measured and corresponding simulation model is established.The generating mechanism and variation law of the interference is analyzed and immunity measures is proposed

which have a definite significance in prevention and management of such interference.