vacon • 119 Parameters
6
Figure 31.Programmable U/f curve
P3.1.4.3 VOLTAGE AT FWP
Above the frequency at the field weakening point, the output voltage remains at the set maxi-
mum value. Below the frequency at the field weakening point, the output voltage depends on
the setting of the U/f curve parameters. See parameters P3.1.4.1, P3.1.4.4 and P3.1.4.5.
When the parameters P3.1.1.1 and P3.1.1.2 (
Motor Nom Voltg and Motor Nom Freq) are set,
the parameters P3.1.4.2 and P3.1.4.3 are automatically given the corresponding values. If you
need different values for the field weakening point and the maximum output voltage, change
these parameters after setting the parameters P3.1.1.1 and P3.1.1.2.
f the programmed maximum frequency is higher than motor nominal frequency, field weaken-
ing point is automatically set at maximum frequency and fwp voltage is set proportionally high-
er than 100%.
This could allow to exploit the higher voltage possibly coming from the panels.
In this situation the current limit has to be set properly, to prevent a motor overload.
If the drive is fed from mains, maximum output frequency will be limited by actual DC voltage,
according to nominal U/f ratio.
P3.1.4.12.1 I/
F START
If the function is activated, the drive is set to current control mode and a constant current de-
fined by P3.1.4.11.3 is fed to the motor until the drive output frequency exceeds the level de-
fined with P3.1.4.11.2. When the output frequency has increased above I/f Start Frequency
level, drive operation mode is changed smoothly back to normal U/f –control mode.
NOTE! This parameter is forced to value ‘1’ Linear when parameter Motor type is set to
value ‘1’
Permanent Magnet Synchronous Motor (PMSM).
NOTE! When this parameter is changed, parameters P3.1.4.2, P3.1.4.3, P3.1.4.4, P3.1.4.5
and P3.1.4.6 will be automatically set to their default values if parameter P3.1.2.2
is set to ‘0’
Induction Motor (IM).
Un
ID603
ID602
U[V]
f[Hz]
9119.emf
P1
P2
P3
ID604
ID605
ID606
Default: Nominal
voltage of the motor
Field weakening point
Default: Nominal
frequency of the motor