Electronic line-shafting control for paper machine drives

The current synchronized motion control methods used in paper machine drives are not designed to possess the inter-shaft stiffness properties which were responsible for the coordinating force inherent in classical, mechanically coupled paper machines. Consequently, these controllers cannot easily maintain coordination for all operating conditions. This paper presents the application of an "electronic line-shafting" control technique which serves to replicate and even improve on the historical, mechanical line-shafted properties. This technique was tested on a four-shaft experimental set up to evaluate such control during periods of drive-limited torque as well as sectional drive load disturbances. The experimental results demonstrate that the "electronic line-shafting" technique significantly improves the coordination, robustness and overall stability of paper machine drives subjected to realistic physical limitations.