Desensitization to voltage sags of a rewinder by using an active dancer roll for tension control

Abstract

Continuous processes in the paper, plastics, textile and other industries, require several drives working in synchronism. Regulation of the mechanical tension in the material is a prime quality criterion. We propose strategies and a control structure that incorporate an active dancer roll in a rewinder system to improve performance of the tensioning loop to disturbances such as voltage supply fluctuations. The linear actuator is used to close a tension loop, the adjoining nip stage maintains the linear actuator close to its mid range of operation and the winder roll is velocity controlled. The effects of voltage variations on the flux observer in the variable speed drives and on loss of performance of the induction motor drives are highlighted. The results show the potential of the proposition as a retrofit option to reduce sensibility to voltage sags in winding systems with little modification to the actual controllers.

Modelling and H∞ low order control of web handling systems with a pendulum dancer

“…17th IFAC World Congress (IFAC'08) Seoul, Korea, July [6][7][8][9][10][11]2008 where x corresponds to the jack piston linear displacement in the cylinder.…”

“…An important number of web process lines use dancer mechanism for attenuating web tension disturbances. There has been recently a growing interest in studying dancer behavior, in comparing active and passive dancers [8], and in improving active dancers due to their ability to attenuate disturbances [9] [10]. All those studies deals with linear dancers, nevertheless pendulum dancers are also very common in industry.…”

Maximum control structure of a five-drive paper system using Energetic Macroscopic Representation

“…With its potentially high dynamical performance, the active dancer also offers a solution to control the web tension at the final roll (Daughter roll) when this roll is eccentric or non circular. Another potential use of active dancers is as a mean to maintain production quality during voltage sags [11] by supplying the dancer by an UPS in segments with critical tension performance.…”

“…The dancer position controller can be implemented in a strategy or management level of the EMR. The position controller is not presented in this paper, but one realization of such a controller is presented in [11].…”

“…In this paper, a control structure is suggested for a fivedrive paper system (Section II) composed of an unwind roll, two tension rolls, a winder roll and an active dancer to reduce the effect of voltage sags [11]. Such a system requires a complex control of the five drives in order to avoid paper damage, and for good dynamical performance.…”