Speed control 1, 2, 3 and 4 (Speed command filter)
(Speed detection filter)
P (Gain)
I (Integral time)
FF(Gain)
(Notch filter resonance frequency)
(Notch filter attenuation level)
Related function code: d25:ASR switching time
These function codes are used to set up the speed control during normal operation.
■ Block diagram of the speed control algorithm
■ Speed command filter (d01/A43/b43/r43)
d01 specifies the time constant determining the first order delay of the speed command filter.
• Data setting range: 0.000 to 5.000 (s)
Modify this data when an excessive overshoot occurs against the change of the reference speed.
Increasing the filter time constant stabilizes the reference speed and reduces overshoot against the change of the
reference speed, but it slows the response speed of the inverter.
■ Speed detection filter (d02/A44/b44/r44)
d02 specifies the time constant determining the first order delay of the speed detection filter.
• Data setting range: 0.000 to 0.100 (s)
Modify this data when the control target (machinery) is oscillatory due to deflection of a drive belt or other causes
so that ripples (oscillatory components) are superimposed on the detected speed, causing hunting (undesirable
oscillation of the system) and blocking the PI processor gain from increasing (resulting in a slow response speed of
the inverter). In addition, if a low encoder (PG) resolution makes the system oscillatory, try to modify this data.
Increasing the time constant stabilizes the detected speed and allows to raise the PI processor gain even with
ripples superimposed on the detected speed. However, speed detection itself is delayed, resulting in a slower
speed response, larger overshoot, or hunting.
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