Question

1a) Compare and contrast phasor diagrams of synchronous generators having round rotors versus those having projecting-pole rotors.

1b) How accurately does simpler cylindrical-rotor theory predict the steady-state performance of the salient-pole machine?

Answer 1

b) ans:,,Saliency introduced reluctance power where improve stability, inertia supply energies during transient making the transient stability higher for salient pole generator and lower for rotor generator,more inertia in salient pole generator,less rotor speed,large diameter,small axial length,less speed hence it has better steady state performance as compared to cylindrical rotor generator

It has been observed that the values of the magnetizing reactances in both d- and q-axis are reduced significantly from their corresponding unsaturated values as a result of nonlinearities introduced by saturation under both steady-state and transient operations. In the round rotor synchronous machine, q-axis magnetic circuit saturates appreciably more than that along the d-axis because of the presence of the rotor teeth. The saturated values of the d- and q-axis self magnetizing reactances and mutual cross magnetizing reactances between the two orthogonal axes under the steady-state operation. Finally, the effect of saturation, particularly the effect of q-axis saturation, on the power system transient stability .