638 D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
DISTANCE ELEMENTS CHAPTER 15: THEORY OF OPERATION
Figure 553: Typical ground distance settings window
Assume the following signals are injected into the D90
Plus
:
Eq. 69
Based on these signals and the programmed settings, the D90
Plus
calculates the following
values:
Eq. 70
From the assumed steady-state injection, the D90
Plus
also calculates the following:
Eq. 71
The following sub-sections describe the operation of each of the distance characteristics
with respect to these values.
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