Out Of Step 78; Identification; Function Block; Functionality - ABB RELION 620 Series Technical Manual

1MAC504801-IB E
4.7.2
4.7.2.1
4.7.2.2
4.7.2.3
620 series ANSI
Technical Manual

Out of step 78

Identification

This function is available in REM620 Ver.2.1 only.
Function description
Out of step protection

Function block

78
V
1
I SWING
1
I
2
DISABLE OSB_Z2
BLOCK SWING_TR
GUID-6D60F825-38E4-4EC1-B8C2-98E237845DA8 V1 EN
Figure 239: Function block

Functionality

The out of step protection function 78 detects out of step conditions by monitoring
impedance.
The protection uses two impedance measurement elements known as inner and outer
blinders on mho characteristics with a timer. The function calculates the impedance. If the
measured impedance stays between inner and outer blinder for a predetermined time and
moves farther inside the inner blinder, then an out of step condition is indicated. Trip is
generated if out of step is indicated and impedance moves out of mho characteristics. The
mho characteristic can be divided into two zones so separate trips can be generated based
on the zone. Tripping can also be selected to occur when the impedance is on the way into
the zone or for when the impedance is on the way out of the zone.
The function contains a blocking functionality. It is possible to block function outputs, the
definite timer or the function itself, if desired.
IEC 61850
identification
OOSRPSB
TRIP
OSB
Section 4
Protection functions
IEC 60617 ANSI/IEEE C37.2
identification device number
φ> 78
503