| 3. Requirements for the excitation system of synchronous generators-2 |
5.2 |
3.2. During generator operation in the grid or at no-load, stable operation of the excitation system must be ensured within the limits from 0.5 to 1.1 of the generator's nominal excitation.3.3. High speed of response
Thyristor excitation systems must provide voltage rise from Ur.nom up to 1.9 Ur.nom in a time of no more than 0.08 s.
According to GOST 21558-76, twofold excitation forcing must be provided when the positive sequence voltage at the generator terminals drops to 0.8 Ug.nom.
3.4. Regulation accuracy
The excitation system with AVR must ensure:
- accuracy of maintaining the positive sequence voltage no more than
1.0%;
- accuracy of maintaining the positive sequence voltage during short-term frequency changes of the synchronous machine voltage from +10% to minus 20% fn
- ±10% instead of 20%;
- range of setpoint change from 0.8 to 1.1 Ug.nom at a setpoint change rate of 0.3 ... 0.4% of nominal voltage per second;
- accuracy of automatic matching of the turbogenerator voltage setpoint to the grid voltage ±0.5% of the nominal voltage of the synchronous machine.
3.5. Statism
Voltage statism on the station busses when compensating for the
reactive resistance of the step-up transformer -
2...5% with statism by the turbogenerator voltage level up to minus 2%.
|