DC motor load analysis at hsm finishing train

Abstract

The hot rolling process uses a plant called a finishing train to achieve the final geometric dimensions of the strip. The finishing train is composed of 7 rolling stands. The reduction of the dimensions of the slab is made with the help of rolling cylinders that are driven by identical DC motors, for the 7 stands of the finishing train but with different speed and torque requirements. During the passage of the strip through the stands of the finishing train, the thickness reduction is different from first stand to the last one, but the material flow must remain constant. This also involves different speeds and forces on each stand. The automation system calculates and controls each motor attached to each stand differently. Moreover, the deformation force required in the stand is different in both value and the drive system that supplies it; for the first four stands the system is electromechanical and for the last three stands it is hydraulic. This difference is also reflected in the load of the gear motors. The main objective of the analysis, performed in this research, is to build an optimized loading model of the rolling motor drive motor. In order to achieve this goal, the analysis was performed on two levels: physical and virtual respectively. Physically, the load analysis involves comparing the parameters of the drive motor for a tensioned stand with an electromechanical system and a stand where the force is developed by a hydraulic system, analysis that is performed in the real finishing train. In the virtual plane, the analysis considers the comparison of the obtained parameters, by simulating the motors in Matlab Simulink with the real data recorded in operation for the same type of strip, thus verifying the factors that definitively influence the functional stability of the finishing train and opening paths for the functional optimization of this drive chain.