Evaluation of Torsional Oscillations in Paper Machine Sections

Abstract

Abstract-Torsional oscillations greatly affect performance and determine the bandwidth (BW) and damping of speed loops. Backlash due to gear reducers can also contribute to the triggering of oscillations, especially when the drive runs at very low load torque. This paper presents a detailed evaluation of these effects in typical electromechanical drive trains applied to paper machine sections. The cases evaluated consider torsional oscillations in two-mass and three-mass systems, and the effect of shaft diameter and length on the resonant frequencies of three typical paper machine sections. Time-domain response plots are evaluated to show the effect of speed response overshoot, reducer backlash, and step or ramp speed commands. Based on these results, mechanical design guidelines are given for the most significant drive train components in order to minimize torsional oscillations of the speed-controlled drive system.

Analysis of Electromechanical Interaction in Aircraft Generator Systems

“…Interaction has been observed in a range of systems, for example sub-synchronous resonance in land based power generation [7,8] causing early fatigue of mechanical components [9], challenges for wind power generation [10,11] causing gearbox failure [12], unpredicted faults in industrial processes such as mills [13], excessive vibration in electric and hybrid-electric vehicle drivetrains [2,14] increasing wear [4], and wave induced instability in marine propulsion systems [15]. Methods for mitigating electro-mechanical interaction include minimising gearbox backlash [16], control scheme disturbance rejection [17] and repositioning of resonant modes through design [18]. However, the aero generator application discussed in this paper is particularly challenging.…”

Adaptive Control of the Electrical Drives with the Elastic Coupling using Kalman Filter

“…Also the performance of the machines used in textile industry is reduced by the non-ideal characteristics of the shaft (Beineke et al, 1997), (Wertz et al, 1999). An analogous problem appears in the paper machine sections (Valenzuela et al, 2005) and in modern servo-drives (Vukosovic & Stojic, 1998), (O'Sullivan et al, 2007), (Shen & Tsai, 2006). Moreover, torsional vibrations decrease the performance of the robot arms (Ferretti et al, 2004), (Huang & Chen, 2004).…”

Controller Design for Three-Mass Resonant System Based on Polynomial Method

“…This simplified approach has been used in different industrial applications [6][7][8]. Vibration suppression and high speed response control in motion control system is an important problem in industry applications [9][10][11]. Control problems of a multi-mass system is especially difficult when not all system variables are measurable, which happens very often in industrial applications [12,13].…”