BONFIGLIOLI Active Cube Applications Manual

•
5.1.1.4 Operation with field weakening
The amount of the induced voltage and thus the stator voltage to be applied by the frequency inverter
will increase in PMSM with the torsional frequency. The maximum torsional frequency of the PMSM is
limited initially by the maximum output voltage of the frequency inverter.
The torsional frequency of the PMSM can be increased further if the effective field is weakened by
superposition (field weakening). To that end, the modulation controller impresses a negative Isd cur-
rent in the machine, once the frequency inverter reaches the modulation limit.
If the speed is increased beyond the rated speed as the result of field weakening, the
open
-circuit voltage of the machine will also increase with the speed.
NOTE
When the frequency inverter is stopped in the field weakening
process, the frequency inverter or
other connected parts may be damaged, when no further measures are taken.
• For operation of a PMSM in the field weakening range, a sufficiently dimensioned brake chopper
must be connected to the frequency inverter, also refer to Chapter 5.1.3 “Brake chopper moni-
toring”.
To activate operation in the field weakening range, Parameter
Ref. Isd Lower Limit 744 is set to a
suitable negative value. This value depends on the characteristics of the machine and the desired field
weakening factor. The negative
Rated Current 371 of the machine would be a practicable setting.
NOTE
If the value is set too high, the magnets might be demagnetized and the machine might be dam-
aged.
Parameter
Unit
Setting range
Default settings
No.
Identifier
744
Ref. Isd lower limit
A
-o·I
FIN
.. o·I
FIN
0.0
5.1.2 Operation with encoder
In the speed sensor mode can be evaluated different systems.
Encoder system
Evaluation unit
Assigned speed sensor
Resolver
EM-RESxx
2
Incremental encoder
EM-ENCxx
2
SinCos encoder
EM-ABS-01
2
Reference pulse encoder
Digital input S6IND
1
30 ACU Spindle Applications 11/13

BONFIGLIOLI Active Cube Specifications

General

Brand	BONFIGLIOLI
Model	Active Cube
Category	Inverter
Language	English