Research And Design Of Indirect Tension Control System In Rewinder

In this paper, many factors which may affect high speed two-drumrewinder indirect tension control system are discussed according to itsrunning characteristic. The thesis mainly discussed the influences ofconstant tension control system which was made by the movementinertia in unwinder mechanism. The thesis calculated the unwinder rollacceleration, the optimized diameter computational method andestimated the paper tension. Finally, the thesis used two kinds ofindirect tension control system which is the DC drive and AC driverewinder. It was a design example for the domestically produced highspeed two-drum rewinder.The rewinder tension control system can be divided into the directtension control system and the indirect tension control system. Thethesis analyzed the direct tension control and the indirect tensioncontrol respective characteristics, the applicable scope and situation.The rewinder required the very high dynamic performance to thetension control system because of the rewinder frequently accelerationand deceleration operation. Therefore, the indirect tension control withdirect tension trimming control plan for the high speed two-drumrewinder was primarily used. But the price of tension sensor isexpensive, and not suitable for the domestically produced two-drumrewinder tension sensor. The conclusion can be made that using indirecttension control plan with various precise compensation to the factorswhich affected the rewinder paper tension, so it is possible to achievethe effect of using direct tension control plan. The paper had given theunwinder roll dynamic torque formula, the corresponding discretizationequation which programs in PLC, and the tension value estimatealgorithm based on unwinder roll torque balance equation. Through thetension estimate and the tension sensor measure value contrasted, it is concluded that the tension estimated value may definitely replace thetension sensor and constitute tension closed-loop control system.The thesis analyzed the rewinder tension control effect when thespeed is invariable, rewinder paper tension value has certain error withdemand tension value, but the tension is stable. If high speed rewinderwas not carried on the compensation to the unwinder roll inertia torque,the rewinder paper actual tension value is variable gradually. It isproved that the effect of unwinder inertia torque to the paper tensioncontrol in the high speed rewinder indirect tension control plan designmust be considered when the rewinder was operated at the constant highspeed stage.When we took the optimization analyzes to the two-drum rewinderindirect tension control system parameter, the article gave severalcomputational methods to unwinder roll diameter in the peculiarcircumstance which prevent it from mutation. The more deeply researchto the unwinder inertia torque computational method is discussed in thisthesis, and the paper analyses the mathematical model of tensionindirect measurement (soft measurement).The thesis introduced separately the DC drive indirect tensioncontrol plan and the high performance AC drive indirect tension controlplan for domestically produced two-drum rewinder control system. Inthe DC drive rewinder control design plan, unwinder roll inertia torque,the acceleration, and the diameter computation with PLC algorithmrealization are introduced as the emphasis. In the AC drive rewindercontrol design plan, the realization method based on the PLC softwarealgorithm indirect tension control plan using the high performancefrequency converter is described. The conclusion is that the DC driverewinder is the quite mature control plan, but using the indirect tensioncontrol plan on the AC drive rewinder is recently the developmentdirection to the future domestically produced two-drum rewinder.