GE Multilin G650 Manual page 213

5.4 PROTECTION ELEMENTS
Table 5–71: VOLTS PER HERTZ ELEMENT SETTINGS
SETPOINT > PROTECTION ELEMENTS > VOLTAGE ELEMENTS > VOLTS PER HERTZ >
VOLTS PER HERTZ 1> VOLTS PER HERTZ 2 > VOLTS PER HERTZ 3
SETTING DESCRIPTION
Function permission
V/Hz Source for element calculations
V/Hz Minimum operating Voltage
V/Hz Pickup Level
V/Hz Curve
V/Hz TD Multiplier
V/Hz Reset Delay
Snapshot Event generation
• Function: This setting allows enabling or disabling the Volts per Hertz element.
• V/Hz Source: This setting allows the user to select the voltage used to calculate the Volt/Hz ratio. If V/Hz source is
configured as "PHASE", the maximum phase among the three voltage channels at any given point in time is the input
voltage signal for element operation (Va, Vb, Vc for WYE conection or Vab, Vbc, Vca for DELTA conection). If V/Hz
source is configured as "AUX VOLTAGE", the element will use the voltage measured through the fourth voltage
transformer (A11-A12).
• V/Hz Minimum Voltage: Minimum operating voltage for this unit, if the voltage in any of the phases or in the auxiliary
voltage input (depending on the V/Hz source setting) is below this value the function will be inhibited.
5
• V/Hz Pickup Level: This setting defines the Volts/Hz level to operate. The unit used for this setting is pu value defined
as 1 pu = Nominal Voltage Setting/ System frequency Setting.
• V/Hz Curve: This setting allows the user to select between "Definite Time" or "Inverse Curve" types A, B or C.
• V/Hz TD Multiplier: In case of having selected "Definite Time", this setting defines the time in seconds. Instantaneous
trips are obtained settings a zero value. Otherwise is the TD multiplier for the inverse curve selected in V/Hz curve
setting.
• V/Hz T-Reset Delay: The element has a linear reset characteristic. The reset delay can be programmed to match the
cooling characteristics of the protected equipment. The element will fully reset from the trip threshold in Volts/Hz T-
Reset seconds.
• Snapshot events:The snapshot event setting enables or disables the snapshot event generation for this element.
Table 5–72: VOLTS PER HERTZ INTERNAL SIGNALS
5.4.9.8 GROUND OVERVOLTAGE ELEMENT (59G)
G650 provides one ground overvoltage element. This function takes the measurement from the auxiliary voltage VTwhen
VG is selected as Auxiliary Voltage in General Settings. The time delay for the 59G element can be set from 0 to 900
seconds, the element has a reset time setting that can be programmed from 0 to 900 seconds.
5-70
NAME
Function
V/Hz Source
V/Hz Minimum Voltage 40.00
V/Hz Pickup Level
V/Hz Curve
V/Hz TD Multiplier
V/Hz Reset Delay
Snapshot Events
Signal Comment
Volts/Hz (1, 2,3) BLOCK Input used to block the (1, 2, 3) element externally
(configurable in Setpoint>Relay
Configuration>Protection Elements)
Volts/Hz (1, 2,3) PKP Output used to indicate a pickup of the (1, 2, 3)
element
Volts/Hz (1, 2,3) OP Output used to indicate an operation of the (1, 2, 3)
element.
G650 Generator Protection & Control System
DEFAULT VALUE STEP
DISABLED N/A
PHASES N/A
0.01 V
1.00 0.01 pu
DEFINITE TIME
1.00 0.01
1.0 0.1 s
ENABLED N/A
5 SETTINGS
RANGE
[DISABLED – ENABLED]
[PHASES – AUX VOLTAGE]
[30.00 : 500.00]
[0.80 : 4.00]
[DEFINITE TIME-CURVE A-
CURVE B – CURVE C]
[0.05 : 600.00]
[0.0 : 900.0]
[DISABLED – ENABLED]
GEK-113285A