Improved Operating Efficiency
6-
19
Improved Operating Efficiency
This section explains functions for improving motor operating efficiency.
Reducing Motor Speed Fluctuation (Slip Compensation Function)
When the load is large, the amount of motor slip also grows large and the motor speed decreases. The slip
compensation function controls the motor at a constant speed, regardless of changes in load. When the motor
is operating at the rated load, constant E2-02 (Motor Rated Slip)
×
the frequency in constant C3-01 is added to
the output frequency.
Related Constants
* The factory setting will change when the control method is changed. The open-loop vector factory settings are given.
Constant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Operation
Control
Methods
MEMOBUS
Register
Open-
loop
Vector
Flux
Vector
Display
C3-01
Slip compensation
gain
Used to improve speed accu-
racy when operating with a
load.
Usually setting is not necessary.
Adjust this constant at the fol-
lowing times.
• When actual speed is low,
increase the set value.
• When actual speed is high,
decrease the set value.
Used as the applicable control
gain when using flux vector
control.
0.0 to
2.5
1.0*
Yes
A
A
260H
Slip Comp Gain
C3-02
Slip compensation
primary delay time
Slip compensation primary
delay time is set in ms units.
Usually setting is not necessary.
Adjust this constant at the fol-
lowing times.
• Reduce the setting when slip
compensation responsive is
slow.
• When speed is not stabilized,
increase the setting.
0 to
10000
3000
ms
*
No
A
A
261H
Slip Comp Time
C3-03
Slip compensation
limit
Sets the slip compensation limit
as a percentage of motor rated
slip.
0 to
250
200%
No
A
No
262H
Slip Comp Limit
C3-04
Slip compensation
selection during
regeneration
0: Disabled.
1: Enabled.
When the slip compensation
during regeneration function
has been activated, as regenera-
tion capacity increases momen-
tarily.
0 or 1
0
No
A
No
263H
Slip Comp Regen
C3-05
Output voltage limit
operation selection
0: Disabled.
1: Enabled. (The motor flux
will be lowered automati-
cally when the output volt-
age become saturated.)
0 or 1
1
No
A
A
264H
Output V limit
