Omron SYSDRIVE 3G3RV, User Manual

Page: 252 / 446

6
-36
n
Selecting Slip Compensation Function During Regeneration
Set
whether to enable or disable the slip compensation function during regeneration.
For
the slip compensation function operates during regeneration, the braking option (braking resistor, Braking
Resistor
Unit, and Braking Unit) may be useful to momentarily increase the regenerative amount.
n
Selecting Output Voltage Limit Operation
If
output voltage saturation occurs while the output voltage limit operation is disabled, the output current will
not
change, but torque control accuracy will be lost. If torque control accuracy is required, change the settings
to
enable the output voltage limit operation.
If
the output voltage limit operation is enabled, motor magnetic flux current is controlled automatically, and
torque
control accuracy is maintained to limit the output voltage references. Consequently, the output current
will
increase by approximately 10% maximum (with rated load) compared with when the output voltage limit
operation
is disabled, so check the Inverter current margin.
Setting Precautions
• If
using the device at medium to low speed only, if the power supply voltage is 10% or more higher than
the
motor rated voltage, or if the torque control accuracy at high speeds is insufficient, it is not necessary to
change
the output voltage limit operation.
• If
the power supply voltage is too low compared with the motor rated voltage, torque control accuracy may
be
lost even if the output voltage limit operation is enabled.
K K K K
Compensating for Insufficient Torque at Startup and Low-speed Opera-
tion (Torque Compensation)
The
torque compensation function detects that the motor load has increased, and increases the output torque.
V/f
control calculates and adjusts the motor primary loss voltage according to the output voltage (V), and
compensates
for insufficient torque at startup and during low-speed operation. Calculate the compensation
voltage
as follows: Motor primary voltage loss × parameter C4-01.
Vector
control separates the motor excitation current and the torque current by calculating the motor primary
current,
and controlling each of the two separately.
Calculate
the torque current as follows: Calculated torque reference × C4-01