Question

A 125 MVA 11 kV three phase 50 Hz synchronous generator has a synchronous reactance of 1.33 p.u. The generator achieves rated open circuit voltage at a field current of 325 A. The generator is connected to a network with an equivalent line-line voltage of 11 kV and an equivalent impedance of 0.17 pu on the generator base. The generator is loaded to a real power of 110 MW.

a- Find the generated voltage Eaf in p.u. such that the network is operating at unity power factor at the external network equivalent voltage. Find the corresponding field current, the generator terminal voltage and power factor.

b- Assume that the generator is operating at its rated terminal voltage. Find the generated voltage Eaf in p.u., the corresponding field current, the generator terminal current and power factor.

Answer 1