Tension Control Solutions

Tension Control Solutions

In the field of industrial automation, some kind of ribbon and wire products, often need to control the tension to achieve the production requirements. Tension control refers to the ability to control persistent tension when the material transport on equipment.


Tension control mechanism includes unwinding mechanism, winding mechanism, stretching mechanism, the dancer roll control mechanism. According to the control methods tension control mechanism includes open loop tension torque mode, closed loop tension torque mode, closed loop tension speed mode. Open loop tension torque mode does not require tension testing mechanism which controls the tension by adjusting the output torque of the motor and is applied to occasions requiring less precision, closed loop tension torque mode increases tension feedback mechanism basing on open loop tension torque mode, in order to adjust output torque by PID and achieve precise control for tension, closed loop tension speed mode based on the feedback signal, through adjusting the operating frequency to control tension indirectly, has high precision of the tension control. 


Open loop tension torque mode has no tension feedback, and drive controls the tension by controlling the output torque. The relationship between the tension F of wire or strip on the roll, the current coil diameter D and the output torque T of spool shaft is: T=F×D/2. It needs higher accuracy of diameter calculation and torque control to control the tension. In addition, because there is no tension feedback, it also needs some compensation on the system inertia and friction torque to ensure constant tension on the wire or strip. MV600T include a built-in rich coil diameter calculation module, supports a variety of roll diameter calculation model and integrates inertia compensation and friction compensation, to support tension control of opened loop tension torque mode. 



Closed loop tension torque mode requires tension detection and feedback ,based on open loop tension torque mode increases PID torque tuning which is obtained by setting the tension and the tension feedback with the PID regulator. Closed loop tension torque mode due to increasing feedback over the open loop tension torque mode, so the system has more robustness and better performance for applications in occasion that requires precise control of the tension. MV600T can meet the harsh requirements of the tension control in the closed loop tension torque mode, with fast and accurate process PID regulator modules, superior precision and dynamic response capabilities vector torque control.



Closed-loop tension speed mode also requires a tension detection and feedback ,and the signal of line speed of material. Drive control the tension on the wire or strip indirectly by controlling the motor speed. This mode need higher requirements of PID regulation and performance of speed control. Since MV600T has good performance of PID control module and precise speed control, it can easily cope with tension control applications and achieve precise control of the tension.




Advantages of MV600T in applications of tension control: 

Excellent vector control performance, ensure the steady accuracy and dynamic response capability on torque and speed control, thus reduce the tension fluctuation. 

Rich roll diameter calculation module support calculating roll diameter through line speed, input signal of coil diameter by analog port directly and circling approach. 

Support inertia and friction torque compensation, enhance the tension control accuracy of torque mode. 

Powerful PID adjustment function is applicable to tension control system with tension feedback and can meet the more stringent accuracy requirements of tension control. 

Supporting high-speed torque compensation, offsets the effects of change of friction with the speed on system, to make tension constant. 

Supports flexible settings of tension taper.