ABB Relion 620 Series - Page 607

I A A A A
prim
= ⋅ + ⋅ +
( )
≈1000 0 020 2 0 0085 0 37. .
(Equation 123)
The power of the stabilizing resistor is calculated as follows.
P
V
W≥
( )
≈
323
3900
27
2
Ω
(Equation 124)
Based on Equation 112 and Equation 113 , the need for voltage dependent resistor is
checked.
U
A
kV
max
. . . .=
⋅
⋅ + + +
( )
≈
12 770
1000
3900 15 3 1 73 0 10 36 2Ω Ω Ω Ω
(Equation 125)
˘
.u V V V kV= ⋅ ⋅ −
( )
≈2 2 323 36200 323 9 6
(Equation 126)
The voltage dependent resistor, one for each phase, is needed in this case because
the voltage during the fault is much higher than 2 kV.
The leakage current through the varistor at the stabilizing voltage can be available
from the varistor manual, assuming that to be approximately 2 mA at stabilizing
voltage.
Iu A≈ 0 002.
(Equation 127)
The sensitivity of the protection can be re-calculated taking into account the
leakage current through the varistor as per Equation 110 .
I A A A A
prim
= ⋅ + ⋅ +
( )
≈1000 0 020 2 0 0085 0 002 39. . .
(Equation 128)
4.3.6.8 Signals
Table 532: MHZPDIF Input signals
Name Type Default Description
ID_A REAl 0.0 Differential current
amplitude (DFT)
phase A
ID_B REAL 0.0 Differential current
amplitude (DFT)
phase B
Table continues on the next page
1MRS757644 H Protection functions
620 series
Technical Manual
607