Application of New Drive Systems for Plate Mill Drives

Recently, certain plans have been made to replace existing motors with the objective of achieving controlled rolling in Japanese plate mills. Application of ac drive systems, which are making rapid progress, can be considered for these plans. A comparison of conventional dc motors, brushless dc motors, and vector-controlled induction motors fed by cycloconverters (cycloconverter IM´s) is introduced from the viewpoint of their characteristics such as power-torque curve, efficiency, and influence of harmonic current on the power system. As a result of comparison it is found that the cycloconverter IM´s can be satisfactorily applied to the plate mills.