Chapter 2 Tension Control Principles
5
any of the following three modes: speed sensorless vector control,
speed sensor vector control, and V/F control.
The principle for the control mode is as follows: calculate a set value for
the matching frequency, f1, according to the material line speed and the
actual curling radius, conduct PID operation through the tension
(position) detection signal to generate a frequency adjustment value f2,
and then output the final frequency f=f1+f2. f1 can basically match the
line speed of the wind-up/roll-down roll with the material line speed, and
then the control requirement can be met with the slight adjustment of f2.
In this way, the problem between the response quickness and the
control stability in close-loop control can be well solved.
In this mode, the tension setting part is inactive, and the target value of
the system control is set in the FA-00PID reference source. The control
result is that the tension (position) feedback signal will be the reference
value of the PID. It should be noted that when using the position signal
(e.g. tension swing, float roll) as the feedback, the actual tension may
not be changed by changing the set value (PID reference value). The
mechanical configuration, such as the counterweight of the tension
swing or float roll, shall be changed to change the tension.
4. Function modules related to close loop speed mode
1) PID part: It is mainly used for setting of group FA. It can also provide
auxiliary function for the second group of PID parameters in group FH.
After all the other parts are correctly set, the PID parameters shall be
adjusted for the final control result.
2) Line speed input part: This part is very important. It has two functions:
