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Nominal Values of
Voltage
Transformers
Voltage Connection
U
E
Table 2-3
Setting Options for the UE Input and their Impact on the Protection Functions
Setting of
UE CONNECTION
(Addr. 0223)
not connected
Processing of U0
measured value
(precisely: √3 U0)
UE connected to
Processing of U0
loading resistor
measured value
(precisely: √3 U0)
UE connected to any
Processing of UE in-
transformer
put (e.g. earth fault
protection on trans-
former side)
UE connected to
Processing of UE in-
broken delta winding
put
UE connected to
Processing of U0
rotor
measured value
(precisely: √3 U0)
UE connected to
Processing of UE in-
neutral transformer
put
Transformation
Ratio U
E
7UM62 Manual
C53000-G1176-C149-3
At addresses 0221 Unom PRIMARY and 0222 Unom SECONDARY, information is
entered regarding the primary nominal voltage and secondary nominal voltages
(phase-to-phase) of the connected voltage transformers.
At address 0223 UE CONNECTION the user specifies to the device which type of volt-
age is connected to the U
processing the input signal. The U
protection functions or for rotor earth fault protection using rated frequency voltage in-
jection (see Section 2.30). Table 2-3 shows the interdependencies for each protection
function.
90-%-Stator Earth
Fault Protection
(Section 2.26)
Determination of 3rd har-
monics from calculated
U0 voltage
(Only U0 3rd harm >
stage usable).
–
–
Processing of UE input
–
Processing of UE input
For the conversion of the displacement voltage U
requires the primary/secondary transformation ratio of the transformer delivering the
voltage. With the exception of the rotor earth fault protection, the 0224 FACTOR
U
E
UE has an impact on those protection functions which process the U
shown in Table 2-3. For this ratio 0224 FACTOR UE the following general formula
applies:
0224 FACTOR UE
In this context, U
VT, prim
displacement voltage applied to the device. If a voltage divider is used, its divider ratio
also influences this factor. The following equation results for the example in Figure 2-
1b with the power system data selected there and an 1:5 voltage divider ratio:
0224 FACTOR UE
input. The device derives from this information the way of
E
input is used for either the various stator earth fault
E
Stator Earth Fault
Protection with
3rd Harmonics
(Section 2.28)
–
Processing of UE input
–
Processing of UE input
–
Processing of UE input
U
VT, prim
---------------------- -
=
U
E, sec
is the primary voltage and U
⁄
(
6.3 kV
-------------------------------- -
=
500 V 5 ⁄
Power System Data 1
100-%-Stator Earth
Rotor Earth Fault
Fault Protection
Protection (R, fn)
(20 Hz)
(Section 2.29)
–
–
–
–
Processing of UE
input
–
in primary quantities, the device
E
input directly, as
E
is the secondary
E, sec
)
3
= 36.4
(Section 2.30)
29
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