Fuji Electric FRENIC-MEGA, Instruction Manual

Page: 192 / 358

5-73
F42 Drive Control Selection 1
H68 (Slip Compensation 1 (Operating conditions))
F42 specifies the motor drive control.
Data for
F42
Drive control Basic control Speed feedback Speed control
0 V/f control with slip compensation inactive
V/f control
Disable
Frequency control
1
Dynamic torque vector control
(with slip compensation and auto torque boost)
Frequency control
with slip compensation
2 V/f control with slip compensation active
3 V/f control with speed sensor
Enable
Frequency control
with automatic speed
regulator (ASR)
4 Dynamic torque vector control with speed sensor
5 Vector control without speed sensor
Vector control
Estimated speed Speed control
with automatic speed
regulator (ASR)
6 Vector control with speed sensor
Enable
„ V/f control with slip compensation inactive
Under this control, the inverter controls a motor with the voltage and frequency according to the V/f pattern specified by
function codes. This control disables all automatically controlled features such as the slip compensation, so no unpredictable
output fluctuation occurs, enabling stable operation with constant output frequency.
„ V/f control with slip compensation active
Applying any load to an induction motor causes a rotational slip due to the motor characteristics, decreasing the motor
rotation. The inverter’s slip compensation function first presumes the slip value of the motor based on the motor torque
generated and raises the output frequency to compensate for the decrease in motor rotation. This prevents the motor from
decreasing the rotation due to the slip.
That is, this function is effective for improving the motor speed control accuracy.
Function code Operation
P12 Rated slip frequency Specify the rated slip frequency.
P09 Slip compensation gain for driving
Adjust the slip compensation amount for driving.
Slip compensation amount for driving =
Rated slip x Slip compensation gain for driving
P11 Slip compensation gain for braking
Adjust the slip compensation amount for braking.
Slip compensation amount for braking =
Rated slip x Slip compensation gain for braking
P10 Slip compensation response time
Specify the slip compensation response time.
Basically, there is no need to modify the default setting.
To improve the accuracy of slip compensation, perform auto-tuning.
H68 enables or disables the slip compensation function according to the motor driving conditions.
Data for H68
Motor driving conditions Motor driving frequency zone
Accel/Decel Constant speed Base frequency or below Above the base frequency
0 Enable Enable Enable Enable
1 Disable Enable Enable Enable
2 Enable Enable Enable Disable
3 Disable Enable Enable Disable
„
Dynamic torque vector control
To get the maximal torque out of a motor, this control calculates the motor torque matched to the load applied and uses it to
optimize the voltage and current vector output.
Selecting this control automatically enables the auto torque boost and slip compensation function so that it is effective for
improving the system response to external disturbances such as load fluctuation, and the motor speed control accuracy.
Note that the inverter may not respond to a rapid load fluctuation since this control is an open-loop V/f control that does not
perform current control, unlike vector control. Other advantage of this control is that the maximum torque per output current
is larger than that of vector control.