Calculating Settings For Breaker Failure Protection Hv-Side, Ccrbrf - ABB Relion 650 Series Applications Manual

Section 3
RET650 setting examples
Z R
= 3
0 N
As the Petersen coil is tuned the zero sequence impedance is:
Z R
= 3
0 N
The Residual voltage at resistive earth-fault in the 22 kV system is:
U
=
U
o
+
1
GUID-AD49C138-F37B-4690-9E37-BA2BAD678A17 V1 EN-US
In our case the requirement is that earth-faults with resistance up to 5 000 Ω shall be
detected. This gives:
U
0
U
phase
GUID-42D376ED-052F-4E9B-B4D9-8D679127BC0C V1 EN-US
Step 1 and step 2 is given the same voltage setting but step 2 shall have longer time delay.
The residual earth-fault protection shall have definite time delay. The time setting is set longer
than the time delay of the earth-fault protection of the outgoing feeders having maximum 2 s
delay. Time delay for step 1 is set to 3 s and the time delay for step 2 is set to 4 s.
1. Set
The settings are made in primary values. These values are given in the base settings in
Global base 2.
2. Set
3. Set
4. Set
5. Set
6. Set
3.1.10 Calculating settings for breaker failure protection HV-side,
CCRBRF
The breaker failure protection can use either contact function in the circuit breaker or current
measurement to detect correct breaker function. For line protections it seems to be most
suitable function is to use current measurement breaker check.
1. Set
The settings are made in primary values. These values are given in the base settings in
Global base 1.
2. Set
3. Set
In the current measurement the three-phase currents out on the line is used. It is also
possible to measure the residual current (analogue input 4). The logics to detect failure
of the circuit breaker can be chosen:
50
j 3 X // — jX Ω / phase
//
N C
Ω / phase
U 1
Phase 0
=
or
× ×
3 R 3 R
U
f f
phase
+
1
Z Z
0 0
1
= =
0 20 .
×
3 5000
+
1
×
3 1270
GlobalBaseSel to 2
Characteristic1 to Definite time
U1> to 20 % of UBase
t1 to 3.0 s
U2> to 20 % of UBase
t2 to 4.0 s
GlobalBaseSel to 1
FunctionMode to Current
BuTripMode to 1 out of 4
© Copyright 2011 ABB Power Grids. All rights reserved
1MRK 504 124-UEN B
(Equation 23)
(Equation 24)
GUID-6BA169D9-043A-42E9-A760-800723945A91 v2
Transformer protection RET650
Application manual