Abstract: The steel and metallurgical industries are characterized by large-scale equipment, networked control systems, and harsh environments. Therefore, the automation system components used in these industries require easy network access and high protection levels. This article introduces the application of Kinco's ED series servo motors in cold rolling mills. As the only domestic servo manufacturer providing PROFIBUS bus-based servo motors, the ED series servo motors hold a significant market share in the industry due to their excellent cost-performance ratio!
Keywords: KincoED servo, Profibus DP bus, cold rolling mill, speed control
I. System Overview
A cold rolling mill is a device that rolls a sheet of a certain thickness to a target thickness at a recrystallization temperature (including room temperature). Cold rolling mills are mainly used in the steel and metallurgical industries for rolling ordinary carbon steel, high-quality medium carbon steel, aluminum, copper, zinc and other metal strips.
Traditional cold rolling mills are controlled by torque motors and DC motors. In recent years, with the development of power electronics and control technologies, and the emergence of high-performance servo motors, the application of servo systems in cold rolling mills has become increasingly widespread.
II. Process Introduction
A cold rolling mill typically consists of three parts: an uncoiler, a main rolling mill, and a coiler (reversible mills do not separate coiling and coiling). Its control system is generally a three-level network control system. The drive level is its zero-level control system, while PLCs and other control systems control the speed or torque of the drive system via bus communication. PROFIBUS is an international, open fieldbus standard that is independent of equipment manufacturers and is widely used in many fields such as manufacturing automation, process automation, building automation, transportation, and power. KincoED servos support the PROFIBUS-DP bus, which is best suited for high-speed data transmission (9.6Kbit/s to 12Mbit/s), enabling very economical device-level networking. It is suitable for communication between field controllers and distributed intelligent I/O, and can meet the fast response time requirements of AC/DC speed control systems.
The core of rolling mill control lies in strip shape and thickness control. To achieve good strip shape and ensure acceptable thickness tolerances, the rolling mill must maintain good speed and tension stability. In terms of control methods, the main rolling mill uses speed control, providing a stable linear speed reference for the entire mill. The uncoiler and coiler use constant tension control.
Speed setting is controlled by the main operator on the control panel. The data is sent to the PLC for processing and then transmitted to each transmission system. Speed setting uses the main unit as the linear speed reference. By setting the diameter of the work roll and the reduction ratio of the gearbox, the motor speed setpoint is given. According to the control functions, speed setting includes forward and reverse jogging functions for fault handling; threading speed setting for threading the rolling mill before production; and rolling mill linear speed setting for normal rolling. Speed is distributed to each transmission system in the form of rotational speed according to the principle of equal linear speed, taking into account the front and rear slip coefficients.
This system requires the following servos:
² Low flexibility in modification and extension functions
• Enables distributed control, improves system response speed, and enhances control accuracy.
² Reduce system unreliability and enhance maintainability
• The motor has a high protection rating, suitable for environments with abundant water vapor.
III. Solution Configuration
Features of Kinco solutions:
The servo driver, which supports PROFIBUSDP bus control, ensures networking between the drive-level control system and other two-level control systems.
The uProfibusDP bus, with its speed of up to 12Mbps, ensures control precision.
The uProfibusDP bus ensures system reliability and interference immunity.
Compared to European servos, u offers extremely high cost-performance.
IV. System Configuration:
System Configuration Table
V. Summary
KincoED servos have been successfully applied in cold rolling mills due to their unique advantage as a domestically produced servo unit, supporting the PROFIBUSDP bus. Their positioning accuracy fully meets customer requirements, the equipment is safe and reliable, and the motors have a full IP65 protection rating suitable for harsh environments. They can completely replace imported servos from Europe and other countries, thus winning the favor of several large domestic cold rolling mill manufacturers with their extremely high cost-performance ratio!
