GE T60 User Manual

5-214 T60 Transformer Protection System GE Multilin
5.6 GROUPED ELEMENTS 5 SETTINGS
5
b) PERCENT DIFFERENTIAL
PATH: SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  TRANSFORMER  PERCENT DIFFERENTIAL
The calculation of differential (I
d
) and restraint (I
r
) currents for the purposes of the percent differential element is described
by the following block diagram, where “” has as its output the vector sum of inputs, and “max” has as its output the input of
maximum magnitude; these calculations are performed for each phase.
The differential current is calculated as a vector sum of currents from all windings after magnitude and angle compensation.
(EQ 5.27)
The restraint current is calculated as a maximum of the same internally compensated currents.
(EQ 5.28)
The element operates if I
d
> PKP and I
d
/ I
r
> K, where PKP represents a percent differential pickup setting and K is a
restraint factor defined by the relays settings Slope 1, Slope 2, and a transition area between breakpoint 1 and breakpoint 2
settings.
 PERCENT
 DIFFERENTIAL
PERCENT DIFFERENTIAL
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
PERCENT DIFFERENTIAL
PICKUP: 0.100 pu
Range: 0.050 to 1.000 pu in steps of 0.001
MESSAGE
PERCENT DIFFERENTIAL
SLOPE 1: 25%
Range: 15 to 100% in steps of 1
MESSAGE
PERCENT DIFFERENTIAL
BREAK 1: 2.000 pu
Range: 1.000 to 2.000 pu in steps of 0.001
MESSAGE
PERCENT DIFFERENTIAL
BREAK 2: 8.000 pu
Range: 2.000 to 30.000 pu in steps of 0.001
MESSAGE
PERCENT DIFFERENTIAL
SLOPE 2: 100%
Range: 50 to 100% in steps of 1
MESSAGE
INRUSH INHIBIT
FUNCTION: Adapt. 2nd
Range: Disabled, Adapt. 2nd, Trad. 2nd
MESSAGE
INRUSH INHIBIT
MODE: Per phase
Range: Per phase, 2-out-of-3, Average
MESSAGE
INRUSH INHIBIT
LEVEL: 20.0% fo
Range: 1.0 to 40.0% of f
0
in steps of 0.1
MESSAGE
OVEREXCITN INHIBIT
FUNCTION: Disabled
Range: Disabled, 5th
MESSAGE
OVEREXCITN INHIBIT
LEVEL: 10.0% fo
Range: 1.0 to 40.0% of f
0
in steps of 0.1
MESSAGE
PERCENT DIFF BLOCK:
Off
Range: FlexLogic operand
MESSAGE
PERCENT DIFFERENTIAL
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
PERCENT DIFFERENTIAL
EVENTS: Disabled
Range: Disabled, Enabled
I
d
I
1
comp
I
2
comp
I
3
comp
I
4
comp
I
5
comp
++++=
I
r
max I
1
comp
I
2
comp
I
3
comp
I
4
comp
I
5
comp
,,,(, )=

GE T60 Specifications

General

Frequency	50/60 Hz
Mounting	Panel Mount
Protection Functions	Overcurrent
Communication Protocols	DNP3
Operating Temperature	+70°C
Enclosure	IP54 (front panel)