Application of electromagnetic force to thin steel plate

To depress the vibration and meandering of a thin steel plate in a steel making plant, electromagnets which derive DC electromagnetic field as well as AC electromagnetic field are applied to the plate. In the case of DC electromagnetic field application, the different pole arrangement is superior to the same pole arrangement for the vertical position control, though the same pole arrangement is superior to the different pole arrangement for the lateral position control. In the case of AC electromagnetic field, frequency characteristics of the linear induction motor is researched. The electromagnetic force has thrust force as well as normal force. Because the normal force consists of the attractive force caused by magnetization and repulsive force caused by Lorentz force, the normal force becomes attractive in low frequency, though the normal force becomes repulsive in high frequency.