ABB REG316 4 Series Operating Instructions Manual page 152

ABB Switzerland Ltd
E. Setting instructions
Settings:
Reference current
Multiplier
Continuously permissible NPS
Minimum operating time
Maximum operating time
Resetting time
This protection is intended for large generators. It is especially
recommended where the level of NPS varies frequently, be-
cause in such cases, higher levels of NPS are permissible for
short periods.
Providing compensation using the reference value of the A/D
channel has not been made, the reference current IB for the
protection is calculated from the rated currents of the generator
I and the c.t's I
GN N1
I
N2
=
IB I
GN
I
N 1
The setting is the ratio IB/I
protection, otherwise "IB-Setting" would be 1.0 I
The following two parameters are required from the manufac-
turer of the generator in order to set k1 and k2:
· the continuously permissible NPS component i
· the permissible energy of the NPS component i
Factor k1 equals the permissible energy:
2
=
k 1 i t
2
Factor k2 equals the continuously permissible component i
k2 = i
2 ¥
3-114
REG 316*4 1MRB520049-Uen / Rev. F
and I as follows:
N2
, where I
N N
IB-Setting
k1-Setting
k2-Setting
t-min
t-max
t-Reset
is the rated current of the
.
N
2 ¥
2
t
2
[p.u.]
[p.u.]
:
2 ¥