Curve 2–4 are suitable for torque-variable load of
fan pump and similar equipment. Users can make
adjustment based on load characteristics to achieve
optimal energy-saving effect.
5: Customized V/F (V/F separation); under this
mode, V is separated from f. Users can adjust f
through the frequency reference channel set by
P00.06 to change the curve characteristic, or adjust
V through the voltage reference channel set by
P04.27 to change the curve characteristics.
Note: The V
b
in the figure below corresponds to
rated motor voltage, and f
b
corresponds to rated
motor frequency.
Output voltage
Output frequency
Linear type
Square type
Torque step-down V/F curve (power of 1.3)
Torque step-down V/F curve (power of 1.7)
Torque step-down V/F curve (power of 2.0)
In order to compensate for low-frequency torque
characteristics, users can make some boost
compensation to the output voltage. P04.01 is
relative to the maximum 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.
Users should select torque boost based on the
load, eg, larger load requires larger torque boost,
however, if the torque boost is too large, the motor
will run at over-excitation, which will cause
increased output current and motor heat-up, thus
degrading the efficiency.
When torque boost is set to 0.0%, the VFD is
automatic torque boost.
Torque boost cut-off threshold: Below this
frequency threshold, the torque boost is valid,
exceeding this threshold will nullify torque boost.
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