Siemens SIPROTEC 7UM62, Manual

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A Appendix
500
7UM62 Manual
C53000-G1176-C149-3
A.5.1 Protection Settings
The settings recommended are the same as in Section 2.29. In addition, the correction
angle (address
5309 PHI I SEF
) and the ohmic contact resistance of the voltage
transformer must be determined during the primary tests, and set at address
5310A
SEF Rps
.
The conversion factor for the resistance (secondary – primary and vice versa) is:
Example:
Primary load resistor: R
L
= 1250
Ω
Voltage transformer: ü
VT
= 10.5 kV/
√
3/500 V
Ohmic divider: ü
Divider
= 1650
Ω
/660
Ω
(5:2)
Current transformer: ü
CT
= 1A/1A
Trip stage: primary 2 k
Ω
, secondary 66
Ω
Alarm stage: primary 5 k
Ω
, secondary 165
Ω
A.5.2 Commissioning
The procedure is the same as described in Section 3.3. Measurements are carried out
with the generator at standstill, and randomly selected tests are then repeated with the
generator running. The following paragraph describes the method of adjustment. A
decade resistor (0 to 10 k
Ω
) is required for the tests.
Generator at
Standstill 1. After checking the connections, a supply voltage is applied to the 20 Hz generator
and the protection device. The following parameters must be set as follows (deliv-
ery settings): address
5309 PHI I SEF
=
0 °
and address
5310A SEF Rps
=
0 Ω
. In fault-free condition (R
E
infinite), read out the angle
j
SEF= from the oper-
ational measured values, and set the appropriate correction angle (see below).
Due to the capacitive earth current, the angle measured must be negative. If it is
not, the connection at the current input must be rotated.
The correction angle is: Phi corr = –90 Grad –(Phi measured)
Example:
Phi measured = –47 Grad, Phi corr = –90 ° + 47 ° = –43 °
The correction angle is set at address
5309 PHI I SEF
.
2. Create a short-circuit (R
E
= 0
Ω
) in the generator starpoint, and read out the mea-
sured fault resistance (address
00764 R SEF=
) from the operational measured
values. This resistance is set at address
5310A SEF Rps
.
FACTOR R SEF
ü
VT
ü
Divider
⋅
ü
CT
---------------------------------
=
FACTOR R SEF
10.5 kV
3 500 V
⋅
----------------------------
5
2
---
⋅
1 A
1 A
---------
------------------------------------
30.3 = =
SEF100I>> 0 1 ,
U
N.Genera tor
3
----------------------------------
R
L
ü
CT
⋅
----------------------------------
⋅
0 1 ,
10.5 kV
3
--------------------
1250
Ω
1A/1A
⋅
-----------------------------------------
⋅
500 mA
≈
= =
urrent stage: