Siemens SIPROTEC 7UM62, Руководство пользователя

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Functions
190
7UM62 Manual
C53000-G1176-C149-3
1.
Ue connected to neutral transformer
: Connection of the U
E
input to the
voltage transformer in the machine starpoint
2.
Ue connected to broken delta winding
: Connection of the U
E
input to
the broken delta winding
3.
Not connected
: Calculation of the displacement voltage by means of the three
phase-earth-voltages, if the U
E
input is not connected
4.
Ue connected to any VT
: measuring of any other voltage; the function 100–
%–stator earth fault protection is blocked.
5.
Ue connected to Rotor
: measuring of any other voltage; the function 100–
%–stator earth fault protection is blocked.
6.
Ue connected to loading Resistor:
The UE-input is used by the 100–
%–stator earth fault protection with 20–Hz–injection. The function 100–%–stator
earth fault protection with 3rd harmonics is blocked.
Ue Connected to
Neutral
Transformer As an earth fault in the starpoint causes a reduction of the measured 3rd harmonic
compared with the faulty case, the protective function is implemented as undervoltage
stage (
5202 U0 3.HARM<
). This arrangement is the preferred application.
Ue Connected to
Broken Delta
Winding If no neutral transformer exists, the protective function is based on the zero
component of the 3rd harmonic of the terminal voltages. This voltage increases in
case of a fault. In this case, the protective function is an overvoltage stage (
5203 U0
3.HARM>
).
Not Connected;
Calculation of U
0
Like for the connection to the broken delta winding, an increase of the 3rd harmonic in
case of a fault also results for the calculated voltage. The
5203 U0 3.HARM>
parameter is also relevant for this application.
Ue Connected to
any VT
Ue Connected to
Rotor With these connection types the function 100–%–stator earth fault protection is
blocked.
Figure 2-91 illustrates the logic diagram of the 100– %–stator earth fault protection.