Universal control block for paper machine drives

Different methods for coordinated motion of the paper or board machine sections were used, mainly depending on the production date. Present solutions are based on individual sectional AC or DC drives as parts of the network control system. The drives are integrated in the control and supervision system with the application of a high performance communication protocol, usually PROFIBUS, Ethernet or DeviceNet. Quality of control system of any paper machine is ensured and the software development procedure is kept straightforward with the use of the universal control block presented in this paper. The generalized structure of the proposed control block is suitable for application on different sections found in paper or board machines, with adequate parametrization. The performance of the block is tested on the dry-end of machine, where the definite amount of sheet tension is required by the technological process. The tension force saliently couples the adjacent drives, which can compromise the performance of the drives, and even lead to unstable operation. The proposed control system structure achieves stable operation of drives coupled through the material, with the possibility to control the sheet tension force.