Grouped Protection Elements; Line Pickup - GE D90 Plus Instruction Manual

CHAPTER 7: PROTECTION
Example use of sources

Grouped protection elements

Line pickup

PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Figure 157: Disturbance detector logic scheme
Plus
Consider a D90 connected as shown below. This configuration could be used on a
transmission line connected into a breaker-and-a-half system. The following figure shows
the arrangement of sources used to provide the functions required in this application, and
the AC module inputs used to provide the data.
Each protection element can be assigned up to six different sets of settings according to
setting group designations 1 to 6. The performance of these elements is defined by the
active setting group at a given time. Multiple setting groups allow the user to conveniently
change protection settings for different operating situations (for example, altered power
system configuration or season of the year). The active setting group can be preset or
selected via the Settings > Protection > Control > Setting Groups menu item.
The line pickup feature uses a combination of undercurrent and undervoltage to identify a
line that has been de-energized (line end open). Alternately, the user may assign a
FlexLogic™ operand that specifies the terminal status. Three instantaneous overcurrent
Figure 158: Example use of sources
GROUPED PROTECTION ELEMENTS
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