Stator Ground - GE G30 Instruction Manual

5.6 GROUPED ELEMENTS
a) MAIN MENU

PATH: SETTINGS GROUPED ELEMENTS
 STATOR
 GROUND
Third harmonic neutral undervoltage protection that responds to the third harmonic in the voltage at the machine neutral
point is provided as a means of stator ground protection.
This element is configured through its individual setting menu. The
source used to provide current and voltage signals for stator ground fault protection. The third harmonic neutral undervolt-
age function is configured as follows:
• Phase voltages measured at the terminal of the machine shall be configured as phase VT banks. The element uses
the voltages to measure the power at the machine terminals for power supervision.
• Phase currents measured at the terminal of the machine shall be configured as phase CT banks. The element uses
the currents to measures the power at the machine terminals for power supervision.
• Voltage measured at the neutral of the machine shall be configured as the auxiliary VT bank. The element extracts the
third harmonic of the auxiliary voltage from the source in order to operate.
b) THIRD HARMONIC NEUTRAL UNDERVOLTAGE (ANSI 27TN)
5

PATH: SETTINGS GROUPED ELEMENTS
 3RD HARM NTRL
 UNDERVOLTAGE
The third harmonic neutral undervoltage function detects a loss of third harmonic voltage at the generator neutral. The per-
centage of stator winding covered by this function depends on the pickup setting and the amount of third harmonic gener-
ated by the machine at the time of the fault. A settable window of forward power can supervise this element for enhanced
security. The element is also supervised by positive-sequence voltage measured at the generator output terminals. This
element can be used with either wye or delta connected VTs on the terminal side and requires the machine neutral voltage
to be connected via an auxiliary voltage channel of a relay VT bank.
5-212

SETTING GROUP 1(6)

STATOR GROUND

SOURCE: SRC1
 3RD HARM NTRL
MESSAGE
 UNDERVOLTAGE

SETTING GROUP 1(6)
3RD HARM NTRL UV
FUNCTION: Disabled
3RD HARM NTRL UV
MESSAGE
PICKUP: 0.3000 pu
3RD HARM NTRL UV PKP
MESSAGE
DELAY: 0.00 s
3RD HARM NTRL UV MAX
MESSAGE
POWER: 0.200 pu
3RD HARM NTRL UV MIN
MESSAGE
POWER: 0.200 pu
3RD HARM NTRL UV
MESSAGE
VOLT SUPV: 0.500 pu
3RD HARM NTRL UV BLK:
MESSAGE
Off
3RD HARM NTRL UV
MESSAGE
TARGET: Self-reset
3RD HARM NTRL UV
MESSAGE
EVENTS: Disabled
G30 Generator Protection System

STATOR GROUND
Range: SRC 1, SRC 2, SRC 3, SRC 4
See page 5–212.
STATOR GROUND SOURCE
 
STATOR GROUND 3RD HARM NTRL UNDERVOLTAGE
Range: Disabled, Enabled
Range: 0.0000 to 3.0000 pu in steps of 0.0001
Range: 0.00 to 600.00 s in steps of 0.01
Range: 0.000 to 1.250 pu in steps of 0.001
Range: 0.000 to 1.250 pu in steps of 0.001
Range: 0.000 to 1.250 pu in steps of 0.001
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
5 SETTINGS
5.6.14 STATOR GROUND
setting specifies a signal
GE Multilin