YASKAWA A1000 Series

5.2 b: Application
160 YASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual
■ b5-34: PID Output Lower Limit
Sets the minimum possible PID controller output as a percentage of the maximum output frequency (E1-04). The lower
limit is disabled when set to 0.00%
■
b5-35: PID Input Limit
Sets the maximum allowed PID input as a percentage of the maximum output frequency (E1-04). Parameter b5-35 acts as
a bipolar limit.
■
b5-38, b5-39: PID Setpoint User Display, PID Setpoint Display Digits
When parameter b5-20 is set to 3, the parameters b5-38 and b5-39 can be used to set a user defined display for the PID
setpoint (b5-19) and PID feedback monitors (U5-01, U5-04).
Parameter b5-38 determines the display value when the maximum frequency is output. Parameter b5-39 determines the
number of digits. The setting value is equal to the number of decimal places.
■
b5-40: Frequency Reference Monitor Content During PID
Sets the content of the frequency reference monitor display (U1-01) when PID control is active.
Setting 0: Frequency Reference after PID
Monitor U1-01 displays the frequency reference increased or reduced for the PID output.
Setting 1: Frequency Reference
Monitor U1-01 displays the frequency reference value.
■
Fine-Tuning PID
Once PID control parameters have been set, fine-tuning may be required. Follow the directions below.
Table 5.11 PID Fine Tuning
No. Name Setting Range Default
b5-34 PID Output Lower Limit -100.0 to 100.0% 0.00%
No. Name Setting Range Default
b5-35 PID Input Limit 0 to 1000.0% 1000.0%
No. Name Setting Range Default
b5-38
PID Setpoint User Display
1 to 60000 Determined by b5-20
b5-39
PID Setpoint Display Digits
0 to 3 Determined by b5-20
No. Name Setting Range Default
b5-40 Frequency Reference Monitor Content During PID 0 or 1 0
Goal Tuning Procedure Result
Overshoot must be suppressed
• Reduce the derivative time (b5-05)
• increase the integral time (b5-03)
Quickly achieve stability, and some
overshoot is permissible
• Decrease the integral time (b5-03)
• Increase the derivative time (b5-05)
Response
Before adjustment
After adjustment
Time
Response
Before adjustment
After adjustment
Time