The Studies And Applications Of Loop Automatic Control System For High Speed Wire-rolling Mill

Since the 1990s, the output of wire in China increased sharply, due to a numbers of high speed wire-rolling mills were imported by many domestic iron and steel works. In the process of high speed wire-rod milling, micro-tension and automatic loop control are usually used, to assure the precision of wire sectional size, and to increase the productivity and the wire quality.In connection with a new domestic high speed wire-rolling mill plant, this paper studies the loop automatic control. On the basis of familiarization with the technological process of mill, the theory of loop control system, and the requirements of technological process to the loop control system, several studies have been made: (1)The control structure of loop control system has been designed. The inner loop corresponds with the speed loop, and the outer loop corresponds with the position loop; (2)A mathematic model has been established for calculating loop height regulation. (3)The PID controller of loop has been designed, and the important parameters of this controller, such as Kp, Kd, Ki and data collection cycle, were discussed. (4) According to the requirements of this project, the SIEMENS programmable logic controllers were used to constitute the computer control system of loop. The program developed in STEP language, after a debugging for many times on the spot, achieved a satisfactory result in controlling.