Goodrive350-UL Series VFD
Basic operation instructions
-63-
2.
For the load featuring decreasing moment, eg, fan and water pump, as the relation between its
actual torque and speed is squared or cubed, it is recommended to adopt the V/F curve corresponds
to power 1.3, 1.7 or 2.0.
b
f
b
V
Output voltage
Output frequency
Straight-type
Torque -down V/F curve (1.3
th
order)
Square-type
Torque -down V/F curve (1.7
th
order)
Torque -down V/F curve (2.0
th
order)
GD350-UL VFD also provides multi-point V/F curve. Users can alter the V/F curve outputted by VFD
through setting the voltage and frequency of the three points in the middle. The whole curve consists
of five points starting from (0Hz, 0V) and ending in (fundamental motor frequency, rated motor
voltage). During setting, it is required that 0≤f1≤f2≤f3≤fundamental motor frequency, and
0≤V1≤V2≤V3≤rated motor voltage
b
f
Output voltage
f1
f2
f3
V1
V2
V3
b
V
%
100
Output frequency
Hz
GD350-UL VFD provides dedicated function codes for SVPWM control mode. Users can improve the
performance of SVPWM through settings.
1.
Torque boost
Torque boost function can effectively compensate for the low-speed torque performance during
SVPWM control. Automatic torque boost has been set by default to enable the VFD to adjust the
torque boost value based on actual load conditions.
Note:
(1)
Torque boost is effective only under torque boost cut-off frequency;
(2)
If the torque boost is too large, low-frequency vibration or overcurrent may occur to the motor, if
such situation occurs, lower the torque boost value.
