WEG CFW08 Vector inverter User Manual page 78

Parameter
P138
Slip Compensation
This parame-
ter is only available
in V/F control
(P202=0 or 1)
Range
[Factory Setting]
Unit Description / Notes
Output Active
Current (I
The parameter P138 is used in the motor slip compensation function.
0.0...10.0%
[0.0]
This function compensates the drop of the motor speed due to
0.1%
load, which is a inherent characteristic relating to the operation
principle of the induction motor.
This speed drop is compensated by increasing the output frequency
(and voltage) (applied to the motor) as a function of the increase of
the active motor current, as shown in the block diagram and in the
V/F curve below.
Output Active
Current (I
DETAILED PARAMETER DESCRIPTION
Speed
Reference (F*)
)
a
Filer
Figure 6.7 - Block diagram of the automatic torque boost function
Output Voltage
Maximum
(P142)
Compensation
Zone
0
4Hz
Figure 6.8 - V/F curve with automatic torque boost
(automatic IxR compensation )
Frequency
Reference (F*)
)
a
Filter
Figure 6.9 - Block diagram of the slip compensation function
Manual
Torque Boost
P136
Automatic
Torque Boost
P137
Output
Frequency
Field Weakening
(P145)
Slip
F
Compensation
P138
P007
Motor
Voltage
Ramp Input
Frequency (Fe)
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