Tension control loop using a linear actuator based on the energetic macroscopic representation

In the paper, plastic, textile and other industries, continuous processes require several drives to work in synchronism. Regulation of the tension in the material is of prime importance for quality. We propose a control structure that incorporates a linear actuator to improve the performance of the tensioning loop to disturbances such as voltage supply fluctuations. Two nip stages and a roller mounted on a linear actuator compose the test system. The linear actuator is used to close a tension loop, the first nip stage is velocity controlled and the second is used to maintain the linear actuator close to its mid range of operation. The control laws are deduced from the maximum control structure of an energetic macroscopic representation of the system. The results show the potential of the approach to reduce sensibility to voltage sags in multi-machine systems.