Designing And Application Of Rewinder's Constant Tension And Load Distribute Control

This paper is aimed at the rewinder technique rebuildingintroduced from Germany by Luohe Yinge paper making group in 90s.The old system uses the direct current control system early used bySiemens, several important parameters such as tension and loaddistribute are adjust by analogue loop, the system is weak at resistingdisturbance and integrating information, there are many faults becauseof the aging elements and low control precision, besides, the velocitycan reach only 600m/min, which is unable to match the producingability of the high-velocity paper machine.In order to solve the above problems, we choose PLC as controller,transducer as executer, OP operating panel as operating station, and allthe fieldbus control method being digital. According to this idea, andfor the sake of decreasing investment, we maintain the old mechanicpart and hydraulic pressure part, changing the direct current drivinginto alternating current driving;adopt Profibus-DP bus and long-rangeI/O instead of the vast I/O line disposal of old system;introduce OP270man-machine interface to replace mechanic button and analogueapparatus. Because of the influence on tension by winding radiusvarying and accelerate/decelerate during rewinding, we propose amethod that combines the direct and indirect tensions into a compoundtension control, and a real-time winding radius computation method, inwhich the direct tension is used to control precision;in a given dynamicprocess, we add some dynamic torque compensation arithmetic, usingindirect tension to increase the antidisturbance of the system, so as toachieve constant tension control. For the control of the double-drummachine, we introduce a principal and subordinate control method afteranalyzing the reason that produces load distribution, this method cannot only keep two machines in-phase, but make the back-drum machinemove following the front-drum machine, so that it controls the loaddistribution.We introduce fieldbus into rewinder, set up a Profibus-DP net,designing communication between principal and subordinate stations,and finally, complete control system's program project and functiondesign of monitor menu. After rebuilding, the operating velocityachieves at 1200m/min, and it is showed that this control system has ahigh precision, runs steadily and trustily, is easy to run and monitor,and so on., it satisfies the control demand of the high-velocityrewinder.