ABB RELION REX640 Technical Manual page 499

1MRS759142 F
Table 566: Operation criteria
Operation mode
Yo
Bo
Go
Yo, Go
Yo, Bo
Go, Bo
Yo, Go, Bo
The options for the
"Reverse".
Figure 282
supported by EFPADM and the settings relevant to that particular characteristic.
The most typical characteristics are highlighted and explained in details in
Chapter 4.2.4.6 Neutral admittance characteristics
calculated neutral admittance Yo moves outside the characteristic (the operation
area is marked with gray).
Y
pri
ni
CT
nu
VT
Example: Admittance setting in the secondary is 5.00 milliSiemens. The CT ratio is
100/1 A and the VT ratio is 11547/100 V. The admittance setting in the primary can
be calculated.
Y
pri
REX640
Technical Manual
Directional mode setting are "Non-directional", "Forward" and
Figure 283
, and
The settings defining the admittance characteristics are given in primary
milliSiemens (mS). The conversion equation for the admittance from
secondary to primary is:
ni
CT
Y
= ⋅
sec
nu
VT
CT ratio for the residual current Io
VT ratio for the residual voltage Uo
100
A
1
mS
5 00 . 4 33
= ⋅ =
11547
V
100
Description
Admittance criterion
Susceptance criterion
Conductance criterion
Admittance criterion combined with the conductance criteri-
on
Admittance criterion combined with the susceptance criteri-
on
Conductance criterion combined with the susceptance crite-
rion
Admittance criterion combined with the conductance and
susceptance criterion
Figure 284
illustrate the admittance characteristics
mS
.
Protection functions
. Operation is achieved when the
(Equation 69)
(Equation 70)
499