Sel 411L - Table 3.30 87 L Applications with In-Line Transformers Winding Configuration Settings

P.3.81
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
87L Differential Elements
Detailed Description of Settings
E87XFMR
This setting enables the in-line transformer feature of the relay, and it must be
set to Y in all relays of the 87L scheme, including outstation relays
(E87CH = 3SS) when protecting in-line transformers.
87MVA
This setting specifies the rated MVA rating of the in-line transformer. The
relay uses this setting to calculate correct tap compensation values for the 87L
currents.
Consider the example shown in Figure 3.44. All three relays must use
87MVA = 200 MVA in this example.
Table 3.30 87L Applications With In-Line Transformers Winding
Configuration Settings
Setting Description Range Default
E87XFMR Enable in-line transformer differential
protection
Y, N N
87MVA MVA rating of the in-line transformer
(MVA)
1–5000 200
87VTWL Line-to-line nominal voltage of the trans-
former winding associated with the
W-terminal current (kV)
1–1000 230
87VTXL Line-to-line nominal voltage of the trans-
former winding associated with the
X-terminal current (kV)
1–1000 230
87CTCWL Vector group compensation matrix for the
W-terminal currents
0–12 0
87CTCXL Vector group compensation matrix for the
X-terminal currents
0–12 0
87XFMRM Lowest ratio of the transformer full load
current to CT primary of the same wind-
ing, among all currents of the 87L zone
0.35–3.5 1
87TTAPW
a
a
Read-only setting.
CT tap for the current Terminal W 1.75–17.5 @ 5A,
0.35–3.5 @1A
2.51
87TTAPX
a
CT tap for the current Terminal X 1.75–17.5 @ 5A,
0.35–3.5 @1A
2.51