ABB REQ650 User Manual

For the time delay characteristic, definite time is used in this network.
3. Set I3> to 80% of IBase (800 A primary current).
4. Set t3 to 1.2 s.
The time delay is set longer than zone 3 (0.8 s) of the distance protection in the
system.
3.1.6 Calculating settings for instantaneous residual overcurrent
protection EFPIOC
The instantaneous residual overcurrent protection shall give very fast fault clearance
of line short circuits close to the substation.
1. Set GlobalBaseSel to 1
The settings are made in primary values. These values are given in the base
settings in Global base 1.
2. Set IN>> to 250% of IBase.
The protection shall not overreach the line and it shall not trip for short circuits
in the reverse direction.
A three-phase short circuit at the remote line end and low source impedance
results in the following fault current to the protection:
0,Re 0,Re
0, ,
0,Re 0, 0, 1 0,Re , 0,
3
3 3
2
ph
sc m sc m
prot o fault
sc m Line sc Home o sc m o Line sc Home
U
Z Z
I I
Z Z Z Z Z Z Z Z
×
= × = ×
+ + × + + +
EQUATION2345 V1 EN
Z
s0Rem
is the zero sequence source impedance at the remote line end, Z
0,Line
is
the line zero sequence impedance and Z
sc0,Home
is the zero sequence source
impedance at the local line end.
A single-phase in the remote busbar (forward fault) results in the following fault
current to the protection:
2.1 87
sc
I kA= Ð - °
EQUATION2346 V1 EN
A single-phase in the local busbar (reverse fault) results in the following fault
current to the protection:
2.1 87
sc
I kA= Ð - °
EQUATION2347 V1 EN
Z
sc
is the positive sequence source impedance of the remote substation and Z
line
is the positive sequence impedance of the line.
3. Set II>> to 2.5 kA .
4. Set IP>> to 250 % of IBase (2500 A primary).
Section 3 1MRK 505 291-UEN A
REQ650 setting examples
52
Application manual

ABB REQ650 Specifications

General

Brand	ABB
Model	REQ650
Category	Protection Device
Language	English