TPG CA-203A, Operating Manual

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Chapter 5 Function parameter
78
PID output as negative 1
PID output as positive, when the feedback signal is greater than PID setting, the
inverter output frequency is required to drop in order to balance PID. Such as winding
tension PID control.
PID output as negative, when the feedback signal is greater than PID setting, the
inverter output frequency is required to rise in order to balance PID. Such as unwinding
tension PID control.
E2.04 Proportional gain (KP) 0.00 to 100.00 1.00 ☆
E2.05 Integration time (Ti) 0.01 to 10.00s 0.10s ☆
E2.06 Differential time (Td) 0.00 to 10.00s 0.00 s
☆
Proportional gain (KP) : used to decide the extent of the PID regulator,the greater
P,the greater adjusting extent. This parameter 100 means that when the deviation of
PID feedback value and setting value is 100%, the PID regulator will adjust the output
frequency command to the maximum output frequency (Ignore the integral and
differential actions) .
Integration time (Ti) : used to decide the speed that PID regulator adjusts
integrally the deviation between feedbacks and settings of PID. The integration time
means that when the deviation of PID feedback value and setting value is 100%, the
integration regulator (Ignore proportional and derivative actions) will successively
adjust to the maximum output frequency (F0.08) for the time. The shorter integration
time, the greater extent of integral adjustment
Differential time (Td) : used to decide the extent that PID regulator adjusts the
deviation between feedbacks and settings of PID. The differential time means that the
feedback value changes 100% within the time, the differential regulator will adjust to
the maximum output frequency (F0.08) (Ignore proportional and integral action) . The
longer differential time, the greater extent of adjustment
PID is the most commonly used control method in the process control, and the
role of its each part varies, the working principle and the adjusting method is briefly
described as follows:
Proportional adjustment (P) : When the deviation between feedback and setting
exists, as for the adjustment amount that the output is proportional to the deviation, if
the deviation is constant, then the adjustment amount will be constant too.
Proportional adjustment can respond quickly to changes in the feedback, but simply
adopt proportional adjustment, which can not realize the control without difference.
The larger proportional gain, the faster the system adjustment, but if the too large
proportional gain will cause oscillation. How to adjust: firstly set integration time to
very long, and set differential time to zero, simply adopt proportional adjustment to
make the system running, then change the setting value to observe the deviation (static
difference) between feedback signal and setting amount, if the static difference changes
in the direction of setting amount (for example, when increasing setting amount, the
feedback amount is always less than setting amount after the system is stable), continue
to increase the proportional gain, and vice versa reduce the proportional gain, repeat the
above process until the static difference is relatively small (it is hard to achieve zero
static difference) .
Integration time (I) : when the deviation between feedback and setting exists, the
Chapter 5 Function parameter
79
output adjustment amount continuously increases, if the deviation persists, the
adjustment amounts will continue to increase until zero deviation. The integration
regulator can effectively eliminate static difference. If the action of integration
regulator shows too strong, the overshoot occurs repeatedly, the system shows unstable
until oscillation. The oscillations caused by too strong integral action is characterized
by that the feedback signal bobs and the range of oscillation gradually increases until
the oscillation. The integration time parameter adjustment generally descend, gradually
adjust the integration time to observe the effect of system adjustment until the system
reaches the steady speed requirements.
Differential time (D) : when the deviation of feedback and setting changes, as for
the adjustment amount that the output is proportional to the deviation, the adjustment
amount only have something to do with the direction and size of deviation change, not
itself direction and size. The role of differential regulation adjusts according to the
changing trends when the feedback signal changes,thereby suppressing the changes of
feedback signal. Please use differential regulator with caution, because the differential
easily amplify the interference of system, especially the interference of high changes
frequency.
E2.07 Sampling period (T) 0.01 to 100.00s 0.10s ☆
E2.08 PID control deviation limit 0.0 to 100.0% 0.0% ☆
Sampling period (T) : refers to the sampling period of feedback amount, the
regulator operates once each sampling period. The greater sampling period, the slower
response.
PID control deviation limit: refers to allowable deviation between PID system
output value and closed-loop setting value, as shown in figure, PID regulator stops
adjustment. The reasonable setting to this function code can adjust the accuracy and
stability of PID system.
Setting
s
Output
frequency
Feedback
amount
t
t
Deviation
limit
The relationship between deviation limit and output frequency
E2.09
Feedback disconnection
detection value
0.0 to 100.0% 0.0%
☆
E2.10 Feedback disconnection 0.0 to 3600.0s 1.0 s
☆