Calculation Of Vk For Distance Zone 1 Close-Up Fault - GE MiCOM P40 Agile Technical Manual

Chapter 16 - Current Transformer Requirements
6.13

CALCULATION OF VK FOR DISTANCE ZONE 1 CLOSE-UP FAULT

SIR = Z /Z =3.32/38.73, which is less than 2, so we need to calculate Vk.
s zone1
Close-up fault current = 40kA primary, = 33.33A secondary
³ K ´ I
V (R + R
k max fmax CT
> 1.4 ´ 33.3 ´ (R
V + R
k CT
V > 46.67(R + R )
k CT L
6.14 CALCULATION OF VK FOR DISTANCE TIME DELAYED ZONES
V > I (R + R )
k f CT L
´ (R
V > I + R ), therefore:
k fthrough CT L
V > 2.14(R + R )
k CT L
6.15 OVERCURRENT ELEMENTS
Phase Elements
³ 0.5I
V (R
K CP CT
Ground Elements
³ 0.5I
V (R
K CN CT
6.16 OVERCURRENT ELEMENTS
³ 0.5I
V (R
K CN CT
426
)
L
), therefore:
L
+ R + R )
L rp
+ 2R + R + R )
L rp rn
+ 2R + R )
L rn
P543i/P545i
P54x1i-TM-EN-1