N5: Feed Forward Control - YASKAWA U1000 Series Technical Manual

 n5: Feed Forward Control
Enabling Feed Forward can improve the drive's responsiveness to speed reference changes in applications where a high
speed control proportional gain setting (ASR gain, C5-01, C5-03) would lead to problems with overshoot, undershoot, or
oscillation. Figure 5.102
and the function principle are illustrated in
for induction or PM motors (A1-02 = 4 or 7), or in Advanced Open Loop Vector Control for PM motors (A1-02 = 6).
Figure 5.102
Figure 5.103
Frequency
reference after
Feed Forward
Soft Starter
U1-20
Note: 1. Feed Forward can only be used in CLV, AOLV/PM, and CLV/PM control modes.
2. Prior to using Feed Forward, always perform Auto-Tuning or set the correct motor data manually. Also perform ASR Auto-Tuning to
set the ASR proportional gain 1 (C5-01), or adjust it manually. Fine-tune the other ASR parameters (C5-) if required.
3. If not restricted by the application, use Inertia Tuning (T1-01 = 8) to have the drive automatically optimize Feed Forward parameters.
If Inertia Tuning cannot be performed, parameters related to Feed Forward should be set manually.
n5-01: Feed Forward Control Selection

Enables or disables the Feed Forward function.
No.
n5-01
Setting 0: Disabled
Setting 1: Enabled
n5-02: Motor Acceleration Time

Sets the time required to accelerate the motor from a full stop up to the rated speed at the rated torque.
No.
n5-02
This value can be set automatically by Inertia Tuning. If Inertia Tuning cannot be performed, use one of the methods
below to determine the setting value for this parameter.
YASKAWA ELECTRIC SIEP C710636 03A YASKAWA U1000 Technical Manual
gives an example of overshoot reduction by Feed Forward. Parameters related to this function
Figure 5.103. Feed Forward can only be used in Closed Loop Vector Control
1050
Overshoot
900
750
0
0 0.5 1
Time (s)
Conventional Speed Control
Figure 5.102 Overshoot Suppression by Feed Forward Control
Feed Forward Torque
Compensation Value
Control
n5-02/03
+
Frequency
-
Reference
Speed
Feedback
Figure 5.103 Feed Forward Control
Name
Feed Forward Control Selection
Parameter Name
Motor Acceleration Time
Suppresses
1050
overshoot at the
end of acceleration
900
750
0
0 0.5 1
Time (s)
common_TMonly
Feed Forward Control
Feed Forward Control Output
U6-26
+
+
ASR P and I
C5-01/02/03/04
U6-25
Feedback Control Output
Setting Range
Setting Range
0.001 to 10.000 s
5.9 n: Special Adjustments
common_TMonly
ASR Delay and Torque reference
Torque Limits
C5-06, L7-
U1-09
Default
0 or 1
Default
Determined by C6-01,
E5-01 and o2-04
0
5
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