Siemens SIMOREG DC-MASTER Operating Instructions Manual page 46

Commissioning
PNU Description
U578 Voltage setpoint for the pre-charging of the SIMOREG CCP quenching
(2578) capacitors
To successfully turn off the thyristors, the set voltage value defines the
minimum charge voltage required for the quenching capacitors in the
SIMOREG CCP. This value is used as setpoint for the two-level controller,
which precharges the quenching capacitors from the line supply.
The maximum pre-charging voltage that can be reached is limited by the -
average rectified value of the line supply voltage that is connected
(minimum value according to the lower tolerance limit as defined by P351).
The value to be set at the parameter U578 should be determined as follows
using the characteristic diagrams provided in the Appendix of these
operating instructions.
To start, the number of the associated characteristic diagram is selected
from the following table for the SIMOREG CCP being used (MLFB
according to parameter n570 or according to the rating plate) and for the
rated armature voltage of the motor according to parameter P101.
MLFB
SIMOREG CCP
6RA7085-6FC00-0
6RA7091-6FC00-0
6RA7095-6FC00-0
6RA7090-6KC00-0
6RA7095-6KC00-0
Then, for the specified values of P111 and r072i002, a search is made for
the associated voltage value in the characteristic diagram.
Below is an example for determining U578 for
n570 = 6RA7091-6FC00-0 (characteristic number = 251)
P101 = 470 V
P111 = 0.23 mH
r072i002 = 890,0 A
According to n570 and r071 characteristic diagram 4 (4A) should be used.
As abscissa value, as an approximation, instead of P111 = 0.23 mH the
next lower grid value of 0.22 mH is used. For r072i002 = 890.0 A, a linear
interpolation is made in the associated current range 800 A to 900 A. The
next higher ordinate grid value for 380 V is used here as an approximation.
As a consequence, U578 = 380 V should be set.
If the armature circuit inductance according to P111 exceeds the value
range shown in the characteristic diagram, then the value should be
determined for the maximum value of P111 that is shown.
Depending on the values of P111 and r072i002, the voltage value being
searched for can lie outside the upper or lower limit shown in the
characteristic diagram.
The upper limit shown in the characteristic diagram is valid for a value of
P351 = -20 % of P078i001 (according to the factory setting). The following
upper limit applies for a value of P351 that deviates from the factory setting:
. 1 35
Upper limit =
46
ENGLISH
MLFB P101
characteristic [V]
number (n570)
250 420
470
251 420
470
252 420
470
253 520
600
720
254 520
600
720
⎛ ⎞
P 351
∗ ∗ ⎜ ⎜ + ⎟ ⎟
P 078 . 001 1
100 %
⎝ ⎠
. 1 073
SIMOREG DC-MASTER Converter Commutation Protector
Value range
[dimension]
Graduation
145 to 830
[V]
[from SW 2.2]
1 V
No. of the associated
characteristic diagram
1, 1A
2, 2A
3, 3A
4, 4A
5, 5A
6, 6A
7.0, 7.0A
7, 7A
8, 8A
9.0, 9.0A
9, 9A
10, 10A
12.2010
No. of See/
indices change
Factory (Access /
setting (FS) state)
Type
Ind: None P052 = 3
FS=145 P051 = 40
Type: O2 online
Siemens AG 6RX1700-0DD74
Operating Instructions