Out-Of-Step Protection Oosppam - ABB REG670 Applications Manual

1MRK 502 071-UEN -
8.5
8.5.1
8.5.2
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
For the TripAngle it is recommended to set this parameter to 90° to assure limited
stress for the circuit breaker.
If the centre of pole slip is within the generator block set N1Limit to 1 to get trip at first
pole slip.
If the centre of pole slip is within the network set N2Limit to 3 to get enable split of the
system before generator trip.

Out-of-step protection OOSPPAM

Identification
Function description
Out-of-step protection
Application
Under balanced and stable conditions, a generator operates with a constant rotor
(power) angle, delivering an active electrical power to the power system, which is
equal to the mechanical input power on the generator axis, minus the small losses in
the generator. In the case of a three-phase fault electrically close to the generator, no
active power can be delivered. Almost all mechanical power from the turbine is under
this condition used to accelerate the moving parts, that is, the rotor and the turbine. If
the fault is not cleared quickly, the generator may not remain in synchronism after the
fault has been cleared. If the generator loses synchronism (Out-of-step) with the rest
of the system, pole slipping occurs. This is characterized by a wild flow of
synchronizing power, which reverses in direction twice for every slip cycle.
The out-of-step phenomenon occurs when a phase opposition occurs periodically
between different parts of a power system. This is often shown in a simplified way as
two equivalent generators connected to each other via an equivalent transmission line
and the phase difference between the equivalent generators is 180 electrical degrees.
Impedance protection
IEC 61850 IEC 60617
identification identification
OOSPPAM
Section 8
ANSI/IEEE C37.2
device number
78
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