Effects of Future Turbine-Generator Characteristics on Transient Stability

Future turbine-generator unit designs, particularly for the larger ratings, are expected to have greater generator reactances and lower unit inertias. Transient stability limits are determined for the future designs in terms of critical fault clearing times for faults on the high voltage transmission lines at the power plant substation. Transient stability limits of the future designs are compared with representative existing generating unit designs. Stability performance of future turbine-generator designs will be very similar to existing designs when considering their respective breaker failure (backup) relay system capabilities. Approximate gains in transient stability critical fault clearing times are also listed when applying various feasible stability control techniques.