Dynamic performance and active damping methods in web winder tension control systems

A web handling system for controlling tension in a web material, the web handling system comprising:

• a winder and unwinder between which a web material is transferred;
• a main drive unit comprising a first electric motor and first adjustable speed drive, the first electric motor and first adjustable speed drive rotationally driving guide rollers to translate the web material from the unwinder to the winder;
• a secondary drive unit comprising a second electric motor and second adjustable speed drive, the second electric motor and second adjustable speed drive rotationally driving the winder to roll the web material onto the winder;
• tension and speed detectors to detect a tension in and a speed of the web material between the unwinder and the winder;
• and
• a control device to control operation of the main drive unit and the secondary drive unit to rotationally drive the guide rollers and the winder, respectively, at desired rotational speeds;
• wherein, in controlling operation of the main drive unit and the secondary drive unit to rotationally drive the guide rollers and the winder at desired rotational speeds, the control device is configured to:
• cause the main drive unit to operate in a velocity mode to set a linear velocity of the web material;
• cause the secondary drive unit to operate in a torque regulated closed-loop tension control mode, via inputs from the tension detectors, so as to control a tension in the web material;
• and
• integrate a speed feedback loop into the torque regulated closed-loop tension control mode, via inputs from the speed detectors, so as to introduce active damping into the tension control.

A method of controlling tension control in a continuous material web translated between an unwinder and a winder in a web winder system, the method comprising:

• controlling a main drive unit of the web winder system to operate in a velocity mode to set a linear velocity of the continuous material web;
• and
• controlling a secondary drive unit of the web winder system to operate in a modified torque regulated closed-loop tension control mode so as to control a tension in the web material;
• wherein, in controlling the secondary drive unit, the modified torque regulated closed-loop tension control mode comprises a torque current loop, a tension loop, and a speed feedback loop to control the tension in the web material.