Percent Differential - GE T60 Instruction Manual

5.6 GROUPED ELEMENTS
b) PERCENT DIFFERENTIAL

PATH: SETTINGS
 PERCENT
 DIFFERENTIAL
5
The calculation of differential (I
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.
The restraint current is calculated as a maximum of the same internally compensated currents.
The element operates if I
restraint factor defined by the relays settings Slope 1, Slope 2, and a transition area between breakpoint 1 and breakpoint 2
settings.
5-214

GROUPED ELEMENTS SETTING GROUP 1(6)

PERCENT DIFFERENTIAL

FUNCTION: Disabled
PERCENT DIFFERENTIAL
MESSAGE
PICKUP:
PERCENT DIFFERENTIAL
MESSAGE
SLOPE 1:
PERCENT DIFFERENTIAL
MESSAGE
BREAK 1: 2.000 pu
PERCENT DIFFERENTIAL
MESSAGE
BREAK 2: 8.000 pu
PERCENT DIFFERENTIAL
MESSAGE
SLOPE 2: 100%
INRUSH INHIBIT
MESSAGE
FUNCTION: Adapt. 2nd
INRUSH INHIBIT
MESSAGE
MODE: Per phase
INRUSH INHIBIT
MESSAGE
LEVEL: 20.0% fo
OVEREXCITN INHIBIT
MESSAGE
FUNCTION: Disabled
OVEREXCITN INHIBIT
MESSAGE
LEVEL: 10.0% fo
PERCENT DIFF BLOCK:
MESSAGE
Off
PERCENT DIFFERENTIAL
MESSAGE
TARGET: Self-reset
PERCENT DIFFERENTIAL
MESSAGE
EVENTS: Disabled
) and restraint (I ) currents for the purposes of the percent differential element is described
d r
I I
= +
d 1
comp
I max I
(
=
r 1
comp
> PKP and I / I > K, where PKP represents a percent differential pickup setting and K is a
d d r
T60 Transformer Protection System

TRANSFORMER
Range: Disabled, Enabled
Range: 0.050 to 1.000 pu in steps of 0.001
0.100 pu
Range: 15 to 100% in steps of 1
25%
Range: 1.000 to 2.000 pu in steps of 0.001
Range: 2.000 to 30.000 pu in steps of 0.001
Range: 50 to 100% in steps of 1
Range: Disabled, Adapt. 2nd, Trad. 2nd
Range: Per phase, 2-out-of-3, Average
Range: 1.0 to 40.0% of f
Range: Disabled, 5th
Range: 1.0 to 40.0% of f
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
I I I I
+ + +
2 3 4 5
comp comp comp comp
I I I I
, )
, , ,
2 3 4 5
comp comp comp comp
5 SETTINGS

PERCENT DIFFERENTIAL
in steps of 0.1
0
in steps of 0.1
0
(EQ 5.27)
(EQ 5.28)
GE Multilin