Vacon 100X series, Applications Manual

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vacon • 117 Parameters
6
P3.1.2.11 U
NDER
V
OLT
. C
ONTROL
This parameter allow the undervoltage controller to be switched out of operation. This may be
useful, for example, if the mains supply voltage varies more than -15% and the application will
not tolerate this undervoltage. In this case, the regulator controls the output frequency taking
the supply fluctuations into account.
P3.1.2.13 S
TATOR
V
OLT
A
DJUST
NOTE! This parameter will be automatically set during the identification run. It is recommend-
ed to make the identification run, if possible. See parameter P3.1.2.4.
Stator voltage adjust
parameter is used only when
Permanent magnet synchronous motor
(PMS motor)
has been selected for parameter P3.1.2.2. This parameter has no affect if
Induc-
tion motor
has been selected. With an induction motor in use, the value has been internally
forced to 100% and it cannot be changed.
When the value of parameter P3.1.2.2 (Motor type) parameter is changed to
PMS Motor
, the
parameters P3.1.4.2 (Field WeakngPnt) and P3.1.4.3 (Voltage at FWP) will be automatically ex-
tended up to the limits of the drive's full output voltage, retaining the defined U/f-ratio. This
internal extension is done to avoid running the PMS motor in the field weakening area because
the PMS motor nominal voltage is typically much lower than the full output voltage capability
of the drive.
PMS motor nominal voltage typically represents the motor’s back-EMF voltage at nominal fre-
quency, but depending on the motor manufacturer, it may represent e.g. the stator voltage at
nominal load.
This parameter gives an easy way to adjust the drive’s U/f curve near to the motor’s back-EMF
curve without needing to change several U/f curve parameters. The StatorVoltAdjust parame-
ter defines the drive’s output voltage in percent of the motor’s nominal voltage at the motor’s
nominal frequency.
The U/f curve of the drive is typically tuned slightly above the back-EMF curve of the motor. The
motor current increases the more the drive’s U/f-curve differs from the motor’s back-EMF -
curve.
Figure 29. Principle of Stator voltage adjustment
f
U
(50..200 %)
20
0
%
10
0
%
50
%
-
9208.emf
Field
Weakening
Point
Field Weakening
Point Voltage
Motor Nominal
Voltage
Motor Nominal
Frequency
Stator Voltage Adjust
ba
ck
EM
F