Omron VARISPEED G7 Instruction Manual page 103

Control
Method
Open-loop
vector con-
trol 2
(A1-02 = 4)
* The setting is given for 200 V Class Inverters. Double the voltage for 400 V Class Inverters.
Do not change the Torque Compensation Gain (C4-01) from its default setting of 1.00 when using open-
•
loop vector control 1.
If speeds are inaccurate during regeneration in open-loop vector control 1, enable Slip Compensation Dur-
•
ing Regeneration (C3-04 = 1).
Use slip compensation to improve speed precision during V/f control (A1-02 = 0).
•
Set the Motor Rated Current (E2-01), Motor Rated Slip (E2-02), and Motor No-load Current (E2-03), and
then adjust the Slip Compensation Gain (C3-01) to between 0.5 and 1.5. The default setting for V/f control
is C3-01 = 0.0 (slip compensation disabled).
To improve speed response and stability in V/f control with a PG (A1-02 = 1), set the ASR constants (C5-
•
01 to C5-05) to between 0.5 and 1.5 times the default. (It is not normally necessary to adjust this setting.)
ASR for V/f control with a PG will only control the output frequency; a high gain, such as is possible for
open-loop vector control 2 or flux vector control, cannot be set.
The following user constants will also indirectly affect the control system.
Name (Constant Number)
Dwell function (b6-01 to b6-04)
Droop function (b7-01 to b7-02)
Acceleration/deceleration times
(C1-01 to C1-11)
S-curve characteristics (C2-01 to C2-04)
-18
4
Table 4.4 Adjusted User Constants (Continued)
Name (Constant
Performance
Number)
ASR proportional gain • Torque and speed
1 (C5-01) and response
ASR proportional gain • Controlling hunting
2 (C5-03) and vibration
ASR integral time 1
• Torque and speed
(high-speed) (C5-02)
response
and
• Controlling hunting
ASR integral time 2
and vibration
(low-speed) (C5-04)
Switching the ASR
proportional gain and
ASR switching fre-
integral time accord-
quency (C5-07)
ing to the output fre-
quency
ASR primary delay • Controlling hunting
time (C5-06) and vibration
• Reducing motor
magnetic noise
Carrier frequency
• Controlling hunting
selection (C6-11)
and vibration at low
speeds (3 Hz or less)
Table 4.5 Constants Indirectly Affecting Control and Applications
Factory
mended
Setting
10.00 to
10.00
50.00
0.300 to
0.500 s
1.000 s
0.0 to max.
0.0 Hz output fre-
quency
0.010 s 0.04 to 0.020
Depends
Default
on the
value
capacity.
Application
Used for heavy loads or large machine backlashes.
Used to soften the torque or to balance the load between two motors. Can
be used when the control mode (A1-02) is set to 3 or 4.
Adjust torque during acceleration and deceleration.
Used to prevent shock when completing acceleration.
Recom-
Adjustment Method
Setting
• Increase the setting if
torque or speed response is
slow.
• Reduce the setting if hunt-
ing or vibration occurs.
• Reduce the setting if
torque or speed response is
slow.
• Increase the setting if hunt-
ing or vibration occurs.
Set the output frequency at
which to change the ASR
proportional gain and inte-
gral time when the same val-
ues cannot be used for both
high-speed and low-speed
operation.
Increase the setting if
machine rigidity is low and
the system vibrates easily.
• Increase the setting if
motor magnetic noise is
high.
• Reduce the setting if hunt-
ing or vibration occurs at
low to middle-range
speeds.