The author analyzes the faults of dry type series iron-core reactor due to imperfect design such as coils burning

inter-turn short circuit

high noise and temperature rise

which leads to unstable grid operation.Consequently

it is suggested that reactance percent

current density

magnetic flux density

and heat transfer area should be correctly selected in design

and attention should be paid to insulation structure.Test results show that these solutions to reducing the reactor faults are effective.