Centre of Pole Slip
en07000003.vsd
Angle = 90°
Angle = -90°
IEC07000003 V1 EN
Figure 105:
The centre of pole slip
The centre of the pole slip can occur in the generator itself or somewhere in the power
system. When a pole slip occurs within the generator it is essential to trip the
generator. If the centre of pole slip occurs outside any generator the power system
should be split into two different parts that could have the ability to get stable
operating conditions.
Pole slip protection (PSPPPAM) function in the IED can be used both for generator
protection application as well as, line protection applications.
The situation with pole slip of a generator can be caused by different reasons.
A short circuit may occur in the external power grid, close to the generator. If the fault
clearing time is too long, the generator will accelerate so much, that the synchronism
cannot be maintained.
Undamped oscillations occur in the power system, where generator groups at different
locations, oscillate against each other. If the connection between the generators is too
weak the magnitude of the oscillations will increase until the angular stability is lost.
The operation of a generator having pole slip will give risk of damages to the
generator, shaft and turbine.
•
At each pole slip there will be significant torque impact on the generator-turbine
shaft.
•
In asynchronous operation there will be induction of currents in parts of the
generator normally not carrying current, thus resulting in increased heating. The
consequence can be damages on insulation and stator/rotor iron.
The Pole slip protection (PSPPPAM) function shall detect pole slip conditions and trip
the generator as fast as possible if the locus of the measured impedance is inside the
generator-transformer block. If the centre of pole slip is outside in the power grid, the
Section 7
1MRK502052-UEN B
Impedance protection
252
Technical manual
Содержание Relion REG670
Страница 1: ...Relion 670 series Generator protection REG670 2 0 IEC Technical manual ...
Страница 2: ......
Страница 44: ...38 ...
Страница 58: ...52 ...
Страница 80: ...74 ...
Страница 106: ...100 ...
Страница 482: ...476 ...
Страница 548: ...542 ...
Страница 570: ...564 ...
Страница 600: ...594 ...
Страница 608: ...602 ...
Страница 630: ...624 ...
Страница 862: ...856 ...
Страница 1094: ...1088 ...
Страница 1226: ...1220 ...
Страница 1250: ...1244 ...
Страница 1297: ...1291 ...