N5: Feed Forward Control - YASKAWA AC Drive-A1000 Technical Manual

5.9 n: Special Adjustments
• Lower n3-13 when flux saturation characteristics cause overcurrent. A high setting sometimes causes overcurrent (oC),
motor overload (oL1), or drive overload (oL2). Lowering n3-21 can also help remedy these problems.
n n3-14: High Frequency Injection during Overexcitation Deceleration
Enables High Frequency Injection while Overexcitation Deceleration is executed. Injecting high frequency into the motor
increases loss and shortens deceleration time. This function tends to increase audible noise from the motor, and may not be
desirable in environments where motor noise is a concern.
No.
n3-14 High Frequency Injection During Overexcitation Deceleration
Setting 0: Disabled
Setting 1: Enabled
n n3-21: High Slip Suppression Current Level
If the motor current exceeds the value set to n3-21 during Overexcitation Deceleration due to flux saturation, the drive
automatically reduces the overexcitation gain. Parameter n3-21 is set as a percentage of the drive rated current.
Set this parameter to a relatively low value to optimize deceleration. If overcurrent, oL1, or oL2 occur during Overexcitation
Deceleration, reduce the overslip suppression current level.
No.
n3-21
n n3-23: Overexcitation Operation Selection
Limits the Overexcitation Deceleration operation selected in parameter L3-04 to forward only or reverse only.
No.
n3-23
Setting 0: Overexcitation Operation as Selected in L3-04 in Forward and Reverse Direction
Setting 1: Overexcitation Operation as Selected in L3-04 in Forward Direction Only
Setting 2: Overexcitation Operation as Selected in L3-04 in Reverse Direction Only
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n5: Feed Forward Control

Note: PM motor control modes are not available on 600 V class drives, CIMR-Ao5oooooooo.
Enabling Feed Forward improves the responsiveness of the drive 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 5.105
the function principle are illustrated in
= 4, 6, or 7).
272
Name
Name
High Slip Suppression Current Level
Name
Overexcitation Operation Selection
gives an example of overshoot reduction by Feed Forward. Parameters related to this function and
Figure 5.106. Feed Forward can only be used in CLV, CLV/PM, or AOLV/PM (A1-02
1050
900
750
0
0 0.5 1
Time (s)
Conventional Speed Control
Figure 5.105 Overshoot Suppression by Feed Forward Control
1050
Overshoot
900
750
0
0 0.5 1
Time (s)
Feed Forward Control
YASKAWA ELECTRIC SIEP C710616 31B YASKAWA AC Drive – A1000 Technical Manual
Setting Range
0, 1
Setting Range
0 to 150%
Setting Range
0 to 2
Suppresses
overshoot at the
end of acceleration
Default
0
Default
100%
Default
0