The Improvement Of Seven Rollers Straightening Machine Control System Based On DCCE PLC

This paper based on relocation and improvement for Seven Rollers Straightening Machine in Dalian Steel Factory, discussed the design and implementation process of Straightening Machine Control System from the engineering point of view. This paper introduced the mechanical systems, electrical control system design, software design, project implementation and site commissioning of Straightening Machine.Programmable Logic Controller is the core of the Control System. The 4 PEC3000 and 1 PEC9000 was selected, which is a distributed controller based on Ethernet communication. PLC system consists of two stations were installed in the Control Cabinet and Control Desk, and the two station net via Industrial Ethernet switch achieved Cooperative Control. This control method greatly reduced the amount of cables between two station and cost savings, which improved anti-jamming capability and reduced the difficulty of maintenance and overhaul.Straightening rollers is driven by two Siemens 6RA70 Series Variable-Speed DC Driver. The paper introduced the design of Variable-Speed DC Driver peripheral circuit. Two drivers have been coupled by peer-to-peer link to work simultaneously. Straightening rollers speed has been synchronized totally by torque limit from master controlled speed followed with slaver.Several sensors for detecting the position of the steel have been added, which improved the automatic mode of production and the accuracy continuity of machine movements. As the result, the system improved the production efficiency By Straightening Machine production technology and production processes of research.Finally, with the actual implementation of the project, the Control Cabinet and Control Desk design, site construction documents design, Siemens 6RA70 Series Variable-Speed DC Driver and Fuji Electric MEGA Series inverter commissioning were detailed introduced.The new control system has been operated reliable for 3 years, and steel straightening effect was quality and precision during the operation. The system meets the technological requirements. The new control system enables improvement of production efficiency by about 30%, which made users feel satisfied. The system passed the project acceptance successfully. It expected that the completion of this control system will bring huge economic benefits.