GE t60 Instruction Manual page 283

5 SETTINGS
b) PERCENT DIFFERENTIAL
PATH: SETTINGS GROUPED ELEMENTS
PERCENT
DIFFERENTIAL
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The calculation of differential (I
by the following block diagram, where "Σ" 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.
In the above equations, K is the restraint factor for the setting and restraint characteristics, accordingly. The element oper-
ates if I > PKP and I > I , where PKP represents a differential pickup setting.
d d r
GE Multilin
SETTING GROUP 1(6)
PERCENT DIFFERENTIAL
FUNCTION: Disabled
PERCENT DIFFERENTIAL
PICKUP: 0.100 pu
PERCENT DIFFERENTIAL
SLOPE 1: 25%
PERCENT DIFFERENTIAL
BREAK 1: 2.000 pu
PERCENT DIFFERENTIAL
BREAK 2: 8.000 pu
PERCENT DIFFERENTIAL
SLOPE 2: 100%
INRUSH INHIBIT
FUNCTION: Adapt. 2nd
INRUSH INHIBIT
MODE: Per phase
INRUSH INHIBIT
LEVEL: 20.0% fo
OVEREXCITN INHIBIT
FUNCTION: Disabled
OVEREXCITN INHIBIT
LEVEL: 10.0% fo
PERCENT DIFF BLOCK:
Off
PERCENT DIFFERENTIAL
TARGET: Self-reset
PERCENT DIFFERENTIAL
EVENTS: Disabled
) and restraint (I ) currents for the purposes of the percent differential element is described
d r
I = I + I + I
d 1 2 3
comp comp comp
×
I = K max I ( , I ,
r 1 2
comp comp
T60 Transformer Protection System
TRANSFORMER PERCENT DIFFERENTIAL
Range: Disabled, Enabled
Range: 0.050 to 1.000 pu in steps of 0.001
Range: 15 to 100% in steps of 1
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
4 5
comp comp
I , I , I )
3 4 5
comp comp comp
5.6 GROUPED ELEMENTS
in steps of 0.1
0
in steps of 0.1
0
(EQ 5.27)
(EQ 5.28)
5-151
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