For asynchronous motor, stator resistance and d-axis
inductance values are normally described in technical
specifications as between line and common (startpoint).
For PM motors, they are typically described in technical
specifications as between line-line. PM motors are typically
built for star connection.
(line to common).
This parameter gives stator winding
resistance (R
s
) similar to asynchronous
motor stator resistance. The stator
resistance is defined for line-to-
common measurement. For line-line
data, where stator resistance is
measured between any 2 lines, divide
by 2.
(line to common).
This parameter gives direct axis
inductance of the PM motor. The d-
axis inductance is defined for phase-
to-common measurement. For line-
line data, where stator resistance is
measured between any 2 lines, divide
by 2.
Table 3.9 Parameters Related to PM Motors
NOTICE
Motor manufacturers provide values for stator resistance
(
parameter P-30 Stator Resistance (Rs)
) and d-axis
inductance (
parameter P-37 d-axis Inductance (Ld)
) in
technical specifications as between line and common
(startpoint) or line between line. There is no general
standard. The different set-ups of stator winding
resistance and induction are shown in
GE frequency converters always require the line-to-
common value. The back EMF of a PM motor is defined
as induced EMF developed across any of 2 phases of
stator winding of a free-running motor. GE frequency
converters always require the line-to-line RMS value
measured at 1000 RPM, mechanical speed of rotation.
This is shown in
Illustration 3.21 Stator Winding Set-ups
Illustration 3.22 Machine Parameter Definitions of Back EMF of
PM Motors
P-38 q-axis Inductance (Lq)
Range:
Function:
0.000 mH
*
[0.000 - 1000
mH]
NOTICE
This parameter cannot be
adjusted while the motor is
running.
Set the value of the q-axis
inductance. See the motor
datasheet.
P-39 Motor Poles
Range:
Function:
4
*
[2 -
100]
NOTICE
This parameter cannot be adjusted while the
motor is running.
Enter the number of motor poles.
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 3.10 Pole Counts and Related Frequencies
shows the pole numbers 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 numbers, not pairs of poles.
The frequency converter creates the initial setting of
based on
and
Parameter Description
60
03/2016 All rights reserved.
DET-620D
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