GE MiCOM P747 Agile, Техническое руководство

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Symbol Description Units
I
f Maximum secondary through-fault current A
I
f max Maximum secondary fault current (same for all feeders) A
I
f max int Maximum secondary contribution from a feeder to an internal fault A
I
f Z1 Maximum secondary phase fault current at Zone 1 reach point A
I
fe Maximum secondary through fault earth current A
I
feZ1 Maximum secondary earth fault current at Zone 1 reach point A
I
fn Maximum prospective secondary earth fault current or 31 x I> setting (whichever is lowest) A
I
fp Maximum prospective secondary phase fault current or 31 x I> setting (whichever is lowest) A
I
m Mutual current A
I
M64
InterMiCOM
64
.
I
Mx
InterMiCOM
64
bit (x=1 to 16)
I
n
Current transformer nominal secondary current.
The rated nominal current of the relay: Software selectable as 1 amp or 5 amp to match the line CT input.
A
I
N Neutral current, or residual current: This results from an internal summation of the three measured phase currents. A
I
N> A neutral (residual) overcurrent element: Detects earth/ground faults. A
I
N>1 First stage of ground overcurrent protection: Could be labeled 51N-1 in ANSI terminology. A
I
N>2
Second stage of ground overcurrent protection: Could be labeled 51N-2 in ANSI terminology. A
I
s Value of stabilizing current A
I
S1 Differential current pick-up setting of biased differential element A
I
S2 Bias current threshold setting of biased differential element A
I
SEF> Sensitive earth fault overcurrent element. A
I
sn
Rated secondary current (I secondary nominal) A
I
sp Stage 2 and 3 setting A
I
st Motor start up current referred to CT secondary side A
K Dimensioning factor
K1 Lower bias slope setting of biased differential element %
K2 Higher bias slope setting of biased differential element %
Ke Dimensioning factor for earth fault
km Distance in kilometers
Kmax Maximum dimensioning factor
Krpa Dimensioning factor for reach point accuracy
Ks Dimensioning factor dependent upon through fault current
Kssc
Short circuit current coefficient or ALF
Kt Dimensioning factor dependent upon operating time
kZm
The mutual compensation factor (mutual compensation of distance elements and fault locator for parallel line coupling
effects).
kZN The residual compensation factor: Ensuring correct reach for ground distance elements.
L
Inductance A
mi Distance in miles.
N Indication of "Neutral" involvement in a fault: i.e. a ground (earth) fault.
P1
Used in IEC terminology to identify the primary CT terminal polarity: Replace by a dot when using ANSI standards.
P2 Used in IEC terminology to identify the primary CT terminal polarity: The non-dot terminal.
Pn Rotating plant rated single phase power W
PN> Wattmetric earth fault protection: Calculated using residual voltage and current quantities.
MiCOM P747 Appendix A - Symbols and Glossary
P747-TM-EN-1 417
P747-TM-EN-1.1