GE L90 Instruction Manual page 368

SYSTEM SETUP
and
POSITIVE ZERO SEQUENCE CAPACITIVE REACTANCE
the protected line are required for charging current compensation calculations. The line capacitive reactance values are
entered in primary kilo-ohms for the total line length.
If shunt reactors are also installed on the line, the resulting value entered in the
SEQ CAPACITIVE REACTANCE
Three-reactor arrangement — Three identical line reactors (X
5
Four-reactor arrangement — Three identical line reactors (X
connected between reactor-bank neutral and the ground.
where
X = the total line positive-sequence capacitive reactance
1line_capac
X = the total line zero-sequence capacitive reactance
0line_capac
X = the total reactor inductive reactance per phase. If identical reactors are installed at both line ends, the value of the
react
inductive reactance is divided by 2 (or 3 for a three-terminal line) before use in the previous equations. If the reactors
installed at both ends of the line are different, the following equations apply:
For two terminal line:
For three terminal line:
where
5-144
Figure 5-64: Charging current compensation configurations
— The values of positive and zero-sequence capacitive reactance of
settings are calculated as follows:
POS SEQ CAPACITIVE REACTANCE
) solidly connected phase to ground:
react
) wye-connected with the fourth reactor (X
react
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
and
ZERO
Eq. 5-8
)
react_n
Eq. 5-9
Eq. 5-10
Eq. 5-11