44. What is performance diagram of a Generator? What are the limiting factors?

The curve between MW (Generator) vs MVAR is the basic performance cuve.

  

The limitations are :

1. Minimum excitation
2. Practical stability limit
3. Rated current
4. Rated MW output
5. 90 deg. Rotor angle
6. Maximum excitation
7. Minimum MW output
8. Transformer Tap limit
9. Generator transformer overfluxing lmit