WEG CFW100 Programming Manual page 69

MOTOR CONTROL
The V/f curve is completely adjustable in four different points as according to
the factory default set a curve pre-adjusted for motors 50 Hz or 60 Hz, as options for P204. This format, point P
defines the amplitude applied at 0 Hz, while P
weakening. Intermediate points P
frequency, for instance, in fans where the load torque is quadratic in relation to the frequency. The field weakening
region is determined between P
The factory default setting of the frequency inverter defines a linear relation of the torque with the frequency by
means of three points (P
The points P [P136, 0 Hz], P
0
and frequency relation imposed to the output approximates the ideal curve for the load. Therefore, for loads in
which the torque behavior is quadratic in relation to the frequency, such as in centrifugal pumps and fans, the
points of the curve can be set or the Quadratic V/f control mode can be used so as to save energy. This Quadratic
8
V/f curve is presented in
✓
NOTE!
In frequencies below 0.1 Hz, the output PWM pulses are cut, except when the inverter is in DC Braking
mode.
✓
NOTE!
Read chapter 3 Installation and Connection of the frequency inverter user's manual before installing,
energizing or operating the inverter.
8-20 | Micro Mini Drives
defines the rated amplitude and frequency and beginning of field
2
allow the setting of the curve for a non-linear relationship between torque and
1
and P , where the amplitude is maintained in 100 %.
2 3
Output
voltage (%)
P142
P143
P136
P
0
P146
Figure 8.13: Curve V/f
, P and P ).
0 1 2
[P143, P146], P [P142, P145] and P
1 2
Figure 8.14 on page 8-20.
Output
voltage (%)
P142
P136
Figure 8.14: Quadratic V/f Curve
P
P
2
P
1
P145 P134
[100 %, P134] can be set so that the voltage
3
P145 P134
Figure 8.13 on page 8-20, although
3
Output
frequency (Hz)
Output
frequency (Hz)
0