n
Fine-Tuning PID
Follow the directions below to fine tune PID control parameters:
Table 5.12 PID Fine Tuning
Goal
Tuning Procedure
Result
Suppress overshoot
• Reduce the derivative time (b5-05)
• Increase the integral time (b5-03)
Response
Before adjustment
After adjustment
Time
Achieve stability quickly while
allowing some overshoot
• Decrease the integral time (b5-03)
• Increase the derivative time (b5-05)
Response
Before adjustment
After adjustment
Time
Suppress long cycle oscillations
(longer than the integral time setting) Increase the integral time (b5-03)
Response
Before adjustment
After adjustment
Time
Suppress short cycle oscillations
• If oscillation cycle time is close to the
derivative time, reduce the derivative
time (b5-05).
• If the derivative time is set to 0.00 s and
oscillations are still a problem, reduce
the proportional gain (b5-02) or increase
the PID primary delay time (b5-08)
Response
Before adjustment
After adjustment
Time
u
b6: Dwell Function
The Dwell function temporarily holds the frequency reference at a predefined value for a set time then continues accelerating
or decelerating.
The Dwell function helps prevent speed loss when starting and stopping a heavy load with induction motors. When running
a PM motor in V/f control, the pause in acceleration allows the PM motor rotor to align with the stator field of the motor and
reduce the starting current.
illustrates how the Dwell function works.
Note:
Set the stopping method to "Ramp to Stop" (b1-03 = 0) to use the Dwell function.
5.2 b: Application
216
YASKAWA ELECTRIC SIEP C710636 04D U1000 Industrial MATRIX Drive Technical Manual
Summary of Contents for U1000 iQpump Drive
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