Improved Operating Efficiency
6-
43
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 V/f control factory settings are given.
Con-
stant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Control Methods
MEMO
BUS
Regis-
ter
V/f
V/f
with
PG
Open
Loop
Vec-
tor
Flux
Vec-
tor
C3-01
Slip compen-
sation gain
Used to improve speed accuracy
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 con-
trol.
0.0 to
2.5
0.0*
Yes
A
No
A
A
20FH
C3-02
Slip compen-
sation pri-
mary 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
2000 ms
*
No
A
No
A
No
210H
C3-03
Slip compen-
sation limit
Sets the slip compensation limit
as a percentage of motor rated
slip.
0 to
250
200%
No
A
No
A
No
211H
C3-04
Slip compen-
sation selec-
tion during
regeneration
0: Disabled.
1: Enabled.
When the slip compensation
during regeneration function has
been activated, as regeneration
capacity increases momentarily,
it may be necessary to use a
braking option (braking resistor,
Braking Resistor Unit or Brak-
ing Unit.)
0 or 1
0
No
A
No
A
No
212H
C3-05
Output volt-
age 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
0
No
No
No
A
A
213H