The Design Of SPM Elongation Control In CAL

The thesis is based on ANSTEEL Group reconstruction project. By combining the design, installation and commissioning of the Skin Pass Mill of a new building CAL, the project uses the Alstom control system to replace the original Siemens control system, for the reason of cost saving and technology accumulation.By combining elongation control theory, the special technologic demand, collection of a large amount of production data and experiment. Theoretical analysis, research and improvement is carried out to increase the production and quality, And these improvements have actual effect.Skin pass is the most important manufacture process of cold rolling procedure, with the very small elongation of length direction (0.3%-3%). In normal production, the const elongation close loop control is used to guarantee production quality. And to get the stable and precise elongation, the analyse, research and optimization is the key parameter in the Skin Pass, which affects the surface quality of steel and the punch quality of subsequent procedure. Now the project is already finished, and the thesis is based on elongation control system, put forward the steps of alteration and these steps have good effect.Research content mainly includes:Firstly, study and digest of Siemens control system, and then finish the programming and commissioning work with Alstom control system.Secondly, analyze the source of elongation measurement error, and improve the measurement system, to get a higher precision and stability of elongation control. And correct the feedback and feedforward parameter under the various speed condition, the control system becomes more stable.Thirdly, add the mass flow close loop control and optimize the rolling force calculation method to solve the IF steel production problem.In the end, conclusions according to research work of project and paper have been drawn; following work and research directions have been pointed out. Some research achievements in this thesis have certain instructional meaning and reference value to future in Skin Pass.