Improvements in the security of the inverting mode of a thyristor-controlled electric drive used in rolling strips of extended range

Rolling heavy strips on hot rolling mills involves considerable line-voltage deviations, which results in the threat of emergency conditions in electric drives with two-region speed control. A method for correction of setting the motor EMF as the line voltage is proposed to improve stability. Experiments have proved the feasibility of reducing the margin of the rectified thyristor converter EMF while maintaining high reliability characteristics of the electric drive.