Omron SYSDRIVE 3G3RV, User Manual

Page: 251 / 446

Improved Operating Efficiency
6-
35
n
Adjusting Slip Compensation Gain
The
C3-01 parameter is initialized as shown below for the control method.
• V/f
control without PG: 0.0
•
Open
loop vector control: 1.0
Set
C3-01 to 1.0 to compensate the rated slip set using the rated torque output status.
Adjust
the slip compensation gain using the following procedure.
1. Set
E2-02 (Motor Rated Slip) and E2-03 (Motor No-load Current) correctly.
The
motor rated slip is calculated from the values on the motor nameplate using the following formula.
Amount
of motor rated slip (Hz) = Motor rated frequency (Hz) - No. of rated rotations (r/min.) × No. of
motor
poles / 120
Set
the values for rated voltage, rated frequency, and no-load current in the motor unladen current. The
motor
rated slip is set automatically in the vector control using autotuning.
2. In
V/f control, set C3-01 to 1.0. Setting this parameter to 0.0 disables slip compensation.
3. Apply
a load, and measure the speed to adjust the slip compensation gain. Adjust the slip compensation
gain
by 0.1 at a time. If the speed is less than the target value, increase the slip compensation gain, and if
the
speed is greater than the target value, reduce the slip compensation gain.
n
Adjusting Slip Compensation Primary Delay Time Constant
Set
the slip compensation primary delay time constant in ms.
The
factory setting is related to the control method as follows:
•
V/f
control without PG: 2000 ms
• Open
loop vector control: 200 ms
Normally,
there is no need to make these settings. When the slip compensation response is low, lower the set
value.
When the speed is unstable, increase the set value.
n
Adjusting Slip Compensation Limit
Set
the upper limit for the slip compensation amount as a percent, taking the motor rated slip amount as 100%.
If
the speed is lower than the target value but does not change even when you adjust the slip compensation
gain,
the motor may have reached the slip compensation limit. Increase the limit, and check the speed again.
Make
the settings, however, to make sure that the value of the slip compensation limit and reference frequency
does
not exceed the tolerance of the machine.
The
following diagram shows the slip compensation limit for the constant torque range and fixed output range.
Fig 6.34 Slip Compensation Limit
Slip compensation limit
Output frequency
E1-06: Base frequency
E1-04: Maximum output frequency