Lenze i950

13.7.1 Correcon of the stator leakage inductance (Lss)...
...and the curr
ent controller parameters by means of the saturaon characterisc
For the most part, the electrical characteriscs of the motor are the relevant factors for an
opmal current controller seng (Vp, Ti), especially the stator resistance and the stator leak-
age inductance (Lss). However, modern motors have their stator leakage inductance changed
along with the current level so that it is impossible to have an opmal current controller set-
ting for all working points at all mes.
For applicaons with operang phases that involve very dierent current and torque require-
ments and, at the same me, high requirements on dynamic drive behaviour, the i700 servo
inverter provides the possibility of the correcon of the stator leakage inductance and the cur-
rent controller sengs by means of the adjustable saturaon characterisc.
The saturaon characterisc is a typical characterisc of motors of one type/size. It does not
depend on the maximum process current of the motor in the prevailing applicaon. Thus the
dened values should be based on the key data of the motors. These are rated motor current,
peak motor current for a limited me and the ulmate motor current.
NOTICE
Impact of the saturaon
characterisc on the current controller feedforward control
▶
The saturaon characterisc is not only used to correct the current controller, but it also
inuences the current controller feedforward control (can be acvated via parameter
0x2941).
The following picture shows a typical saturaon
characterisc of an MCS motor:
0 % 10 % 20 % 30 % 40 % 50 % 60 % 70 % 80 % 90 % 100 %
0 %
20 %
40 %
60 %
80 %
100 %
120 %
I/I
max
L/L
n
The saturaon
characterisc represents the change in inductance (L/Ln) as a funcon of the
motor current (I/Imax). The variables of both axes which were scaled to a reference value are
represented as percentages.
•
When a Lenz
e motor is selected, the
saturaon characterisc is already lled with values
typical of the series.
Conguring the motor control
Fine adjus
tment of the motor model
Correcon of the stator leakage inductance (Lss)...
275