Poles ~n
n
@ 50 Hz
~n
n
@ 60 Hz
2
2700–2880
3250–3460
4
1350–1450
1625–1730
6
700–960
840–1153
Table 4.3 Pole Number for Normal Speed Ranges
shows the pole number for normal speed ranges
of various motor types. Define motors designed for other
frequencies separately. The motor pole value is always an
even number because it refers to the total pole number,
not pairs of poles. The frequency converter creates the
initial setting of
parameter 1-39 Motor Poles
based on
parameter 1-23 Motor Frequency
and
1-40 Back EMF at 1000 RPM
Range:
Function:
Size
related
*
[0 - 9000 V]
NOTICE
This parameter is only active
when
parameter 1-10 Motor
Construction
is set to options
that enable PM (permanent
magnet) motors.
Set the nominal back EMF for the
motor when running at 1000 RPM.
Back EMF is the voltage generated
by a PM motor when no frequency
converter is connected and the
shaft is turned externally. Back EMF
is normally specified for nominal
motor speed or for 1000 RPM
measured between 2 lines. If the
value is not available for a motor
speed of 1000 RPM, calculate the
correct value as follows. If back EMF
is for example 320 V at 1800 RPM,
it can be calculated at 1000 RPM:
Example
Back EMF 320 V at 1800 RPM. Back
EMF=(Voltage/
RPM)*1000=(320/1800)*1000=178.
NOTICE
When using PM motors, it is
recommended to use brake
resistors.
1-41 Motor Angle Offset
Range:
Function:
0
*
[-32768 -
32767]
NOTICE
This parameter is only active
when
parameter 1-10 Motor
Construction
is set to
[1] PM,
non-salient SPM
(Permanent
Magnet Motor).
Enter the correct offset angle
between the PM motor and the
index position (single-turn) of the
attached encoder or resolver. The
value range of 0–32768
corresponds to 0–2 x pi (radians).
To obtain the offset angle value:
After frequency converter start-up,
apply DC hold and enter the value
of
into
this parameter.
1-46 Position Detection Gain
Range:
Function:
100 %
*
[20 - 200 %]
Adjusts the amplitude of the test
pulse during position detection at
start. Adjust this parameter to
improve the position measurement.
1-47 Torque Calibration
Option:
Function:
Use this parameter to optimize the
torque estimate in the full speed
range. The estimated torque is
based on the shaft power, P
shaft
=
P
m
- R
s
x I
2
. Make sure that the R
s
value is correct. The R
s
value in this
formula is equal to the power loss
in the motor, the cable, and the
frequency converter. When this
parameter is active, the frequency
converter calculates the R
s
value
during power-up, ensuring the
optimal torque estimate and
optimal performance. Use this
feature in cases when it is not
possible to adjust
parameter 1-30 Stator Resistance (Rs)
on each frequency converter to
compensate for the cable length,
frequency converter losses, and the
temperature deviation on the
motor.
[0]
Off
Parameter Descriptions
Programming Guide
MG06J202
Danfoss A/S © 03/2019 All rights reserved.
39
4
4
Summary of Contents for VLT AutomationDrive FC 361
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