GE D30 Instruction Manual page 309

CHAPTER 5: SETTINGS
Figure 5-95: Power swing detect quadrilateral operating characteristics
The FlexLogic output operands for the power swing detect element are as follows:
•
POWER SWING OUTER, POWER SWING
are auxiliary operands that facilitate testing and special applications
POWER SWING TMR4 PKP
• blocks selected protection elements, such as distance functions
POWER SWING BLOCK
• blocks those protection elements that are intended to be blocked under power swings, but
POWER SWING UN/BLOCK
subsequently unblocked when a fault occurs after the power swing blocking condition has been established
• indicates that an adaptive disturbance detector integrated with the element has picked up. This
POWER SWING 50DD
operand triggers on faults occurring during power swing conditions. This includes both three-phase and single-pole-
open conditions.
• indicates an unstable power swing with an incoming locus (the locus enters the inner
POWER SWING INCOMING
characteristic)
• indicates an unstable power swing with an outgoing locus (the locus leaving the outer
POWER SWING OUTGOING
characteristic). This operand can be used to count unstable swings and take certain action only after a pre-defined
number of unstable power swings.
• is a trip command
POWER SWING TRIP
The settings for the power swing detect element are as follows.
— This setting enables and disables the power swing detection element. The setting applies to
POWER SWING FUNCTION
both power swing blocking and out-of-step tripping functions.
— The source setting identifies the signal source for both blocking and tripping functions.
POWER SWING SOURCE
— This setting selects the shapes (either "Mho" or "Quad") of the outer, middle, and inner
POWER SWING SHAPE
characteristics of the power swing detect element. The operating principle is not affected. The "Mho" characteristics use
the left and right blinders.
— This setting selects between the two-step and three-step operating modes and applies it to both
POWER SWING MODE
power swing blocking and out-of-step tripping functions. The three-step mode applies if there is enough space between
the maximum load impedances and distance characteristics of the relay that all three (outer, middle, and inner)
D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
X
FWD RCA
MIDDLE, POWER SWING INNER, POWER SWING TMR2
GROUPED ELEMENTS
R
PKP, and
PKP, POWER SWING TMR3
5
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