Danfoss VLT Refrigeration Drive FC 103 Programming Manual page 44

Parameter Description
1-37 d-axis Inductance (Ld)
Range:
Size [0.000 -
related 1000.000
*
mH]
3 3
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.
Parameter 1-30 Stator
Resistance (Rs)
(line to common).
Parameter 1-37 d-axis
Inductance (Ld)
(line to common).
Parameter 1-40 Back EMF
at 1000 RPM
RMS (line to line value).
Table 3.4 Parameters Related to PM Motors
42
®
VLT Refrigeration Drive FC 103
Function:
NOTICE
This parameter is only active
when parameter 1-10 Motor
Construction is set to [1] PM,
non-salient SPM.
Enter the value of the d-axis
inductance. Obtain the value from the
PM motor datasheet.
This parameter gives stator winding
resistance (R ) similar to asynchronous
s
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.
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.
This parameter gives back EMF across
stator terminal of PM motor at 1000
RPM mechanical speed specifically. It
is defined between line-to-line and
expressed in RMS value.
Danfoss A/S © 05/2016 All rights reserved.
NOTICE
Motor manufacturers provide values for stator resistance
(parameter 1-30 Stator Resistance (Rs)) and d-axis
inductance (parameter 1-37 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 Illustration 3.6.
Danfoss 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. Danfoss
frequency converters always require the line-to-line RMS
value measured at 1000 RPM, mechanical speed of
rotation. This is shown in Illustration 3.7).
Line to common (starpoint)
Rs and Ld
Illustration 3.6 Stator Winding Set-ups
Permanent magnet motors
Line to Line Back
Emf in RMS Value
at 1000 rpm
Speed (mech)
Illustration 3.7 Machine Parameter Definitions of Back EMF of
PM Motors
1-38 q-axis Inductance (Lq)
Range: Function:
NOTICE
Size related [0.000 - 1000
*
mH]
This parameter cannot be
adjusted while the motor is
running.
Set the value of the q-axis
inductance. See the motor
datasheet.
Line to line values
Rs and Ld
MG16H202