GE D90 Plus Instruction Manual page 237

CHAPTER 7: PROTECTION
Negative-sequence overvoltage
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Block
Range: any FlexLogic™ operand or shared operand
Default: Off
Assertion of the operand assigned to this setting blocks the neutral overvoltage
element.
Events
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the logging of neutral overvoltage events in the
sequence of events recorder.
The logic for the neutral overvoltage element is shown below. The logic is identical for all
neutral overvoltage elements.
Figure 181: Neutral overvoltage scheme logic
The negative-sequence overvoltage element may be used to detect loss of one or two
phases of the source, a reversed phase sequence of voltage, or a non-symmetrical system
voltage condition.
Select the Settings > Protection > Elements > Group 1 > Voltage > Negative Sequence
OV menu item to open the negative-sequence overvoltage configuration window.
Figure 182: Negative-sequence overvoltage configuration settings
The following settings are available for each negative-sequence overvoltage element.
Function
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the negative-sequence overvoltage protection
element.
GROUPED PROTECTION ELEMENTS
229