In order to compensate for low-frequency torque
characteristics, you can make some boost
compensation for the output voltage. P04.01 is
relative to the max. output voltage V
b
.
P04.02 defines the percentage of cut-off
frequency of manual torque boost to the rated
motor frequency f
b
. Torque boost can improve
the low-frequency torque characteristics of V/F.
You need to select torque boost based on the
load. For example, larger load requires larger
torque boost, however, if the torque boost is too
large, the motor will run at over-excitation, which
may cause increased output current and motor
overheating, thus decreasing the efficiency.
When torque boost is set to 0.0%, the VFD uses
automatic torque boost.
Torque boost cut-off threshold: Below this
frequency threshold, torque boost is valid;
exceeding this threshold will invalidate torque
boost.
P04.01 setting range: 0.0%: Automatic;
0.1%–10.0% (of the rated voltage of motor 2)
P04.02 setting range: 0.0%–50.0% (of the rated
voltage of motor 2)
When P04.00=1 (multi-dot V/F curve), you can
set the V/F curve through P04.03–P04.08.
The V/F curve is generally set according to the
load characteristics of the motor.
Note: V1 < V2 < V3, f1 < f2 < f3. Too high
voltage for low frequency will cause motor
overheat or damage and cause VFD overcurrent