Pid Auto Tuning Function - Toshiba TOSVERT VF-AS3 Instruction Manual

4. 4
■ Function
This function is to estimate PID proportional gain and PID integral gain of PID control by auto tuning.
You can set the amount of step [A307] and the number of repetitions [A306] to be given to the system during
auto tuning.
When [A305] is set to "1", the step amount [A307] is added to the system. After a while the system stabilized,
adding the step amount is stopped. Repeat this process [A306] times.
When the predetermined number of iterations has been completed, the PID proportional gain and PID integral
gain of the PID control are estimated and automatically written to each parameter.
● Preparation for PID auto tuning
• Make settings related to PID control and put it in a state where PID control can be operated.
• Confirm that PID actual load operation works well.
• Confirm the feedback signal at PID actual load operation, and set [A307](step amount) according to the
4
signal level. Because the target value fluctuates up and down by auto tuning,
• Set the number of times to change the target value [A306].
● PID auto tuning procedure
• Turn on the run command, and operate the inverter with PID.
• Confirm that the PID control is stable.
At this time, please check whether PID control 1 is enabled or PID control 2 is enabled.
• Set [A305] to "1".
• PID auto tuning starts. "tUn" is displayed on the LED operation panel (or LCD operation panel) during auto
tuning.
• Adding step amount [A306] times (3 times when [A306] = "0"), calculate the PID gain automatically, then
complete auto tuning.
When the first PID is enabled, the gain of the first PID ([F 362], [F 363]) is automatically changed.
When the 2nd PID is enabled, the gain of the 2nd PID ([F312], [F313]) is automatically changed.
9
• When auto tuning is completed, the set value of [A305] returns to "0" and "tUn" is not displayed.
■ Caution
• As auto tuning gives step change to the system in actual load operation, the system may become unstable.
Please prepare in case the system becomes unstable so that you can put the operation command or the
free-run command immediately.
• When the next state occurs, auto tuning is terminated halfway. In that case, return to [A305] = "0" and do
not change the PID gain value.
- When PID stops (including trip and operation stop)
- When PID 1 and 2 are switched
- When "A305" is set to "0"
4. Setting for PID control

PID auto tuning function

Title Parameter name
A305 PID control auto-tuning
A306 Number of process amount variation
at PID control auto-tuning
A307 Process amount variation at PID
control auto-tuning
Adjustment range
0: Disabled
1: Enabled (0 after excecution)
2: -
0: Automatic (3 times)
1 - 10 (times)
5 - 100 (%)
4-16
E6582112
Default
setting
0
0
10
VF-AS3