Vacon 100X series, Руководство по применению

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Parameters vacon • 118
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6
P3.1.3.1 C
URRENT LIMIT
This parameter determines the maximum motor current from the AC drive. The parameter
value range differs from size to size.
When the current limit is active the drive output frequency is decreased.
NOTE: This is not an overcurrent trip limit.
6.2.2 Open Loop
P3.1.4.1 U/
F RATIO
Figure 30.Linear and squared change of motor voltage
Table 112.
Selection
number
Selection name Description
0 Linear The voltage of the motor changes linearly as a function of output
frequency from zero frequency voltage (P3.1.4.6) )to the field
weakening point (FWP) voltage (P3.1.4.3) at FWP frequency
(P3.1.4.2) This default setting should be used if there is no special
need for another setting.
1 Squared The voltage of the motor changes from zero point voltage
(P3.1.4.6) following a squared curve form from zero to the field
weakening point (P3.1.4.2) The motor runs undermagnetised
below the field weakening point and produces less torque. Squared
U/f ratio can be used in applications where torque demand is pro-
portional to the square of the speed, e.g. in centrifugal fans and
pumps.
2 Programmable The U/f curve can be programmed with three different points (see
Figure 31 ): Zero frequency voltage (P1), Midpoint voltage/fre-
quency (P2) and Fieldweakening point (P3). Programmable U/f
curve can be used if more torque is needed at low frequencies. The
optimal settings can automatically be achieved with Motor identifi-
cation run (P3.1.2.4).
U[V]
f[Hz]
9094.emf
Un
ID603
ID602
Default: Nominal
voltage of the motor
Linear
Squared
Field
weakening
point
Default:
Nominal frequency
of the motor