2.3 Power System Data 1
35
7UM61 Manual
C53000-G1176-C127-3
Iee Transformation
Ratios
For conversion of the ground current Iee in primary quantities, the device requires the
primary/secondary transformation ratio of the transformer. This is set at address
213
FACTOR IEE
.
Nominal Values of
Voltage Transform-
ers
At addresses
221
Unom PRIMARY
and
222
Unom SECONDARY
, information is entered
regarding the primary nominal voltage and secondary nominal voltages (phase-to-
phase) of the connected voltage transformers.
Voltage Connec-
tion U
E
At address
223
UE CONNECTION
the user specifies to the device which type of
voltage is connected to the UE input. The device establishes from this information how
to process the input signal. The following table shows the interdependencies for each
protection function.
Table 2-1
Setting Options for the UE Input and their Impact on the Protection Functions
UE Transformation
Ratio
For conversion of the displacement voltage U
E
to primary quantities, the device re-
quires the primary/secondary transformation ratio of the transformer delivering the UE
voltage. With the exception of the rotor earth fault protection, the
224
FACTOR UE
has
an impact on those protection functions which process the UE input directly, as shown
in Table 2-1. For this ratio
224
FACTOR UE
the following generally applies:
In this context, U
VT, prim
is the primary voltage (generally phase-ground voltage) and
U
E, sec
is the secondary displacement voltage applied to the device. If a voltage divider
is used, its division ratio also influences this factor. The following equation results for
the example in Section 2.1, unit transformer connection figure, with the power system
data selected there and an 1:5 voltage divider ratio
Setting for UE CONNEC-
TION (Addr. 0223)
90% Stator Earth Fault
Protection
Stator Earth Fault Protec-
tion with 3rd Harmonic
not connected
Processing of U0 computed
value (exactly:
√
3 U0)
The 3rd harmonic is deter-
mined from the computed
U0 voltage (U0 3rd harm >
stage only usable).
UE connected to any trans-
former
Processing of UE input
(e.g. earth fault protection
on transformer side)
–
UE connected to broken
delta winding
Processing of UE input
Processing of UE input
UE connected to neutral
transformer
Processing of UE input
Processing of UE input
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Содержание Siprotec 7UM611
Страница 16: ...Contents 16 7UM61 Manual C53000 G1176 C127 3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 232: ...2 Functions 232 7UM61 Manual C53000 G1176 C127 3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 292: ...3 Mounting and Commissioning 292 7UM61 Manual C53000 G1176 C127 3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 410: ...A Appendix 410 7UM61 Manual C53000 G1176 C127 3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 412: ...Literature 412 7UM61 Manual C53000 G1176 C127 3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...