A synchronous generator is rated at 645 MVA, 24 kV, 0.9 power factor lagging. It has a synchronous reactance of 1,2 ohm. The generator feeds full load at 0,9 power factor with excitation emf E_f=1.99∠37.5o . Assume Base MVA = 645 MVA, Base kV = 24 kV. Calculate load angle for following conditions: (ii) If excitation is reduced by 50% at half real load,

H.W Q1) A four pole, three-phase synchronous generator is rated 250 MVA, its terminal voltage is 24 kV, the synchronous reactance is: 125%. ERI • Calculate the synchronous reactance in ohm. Calculate the rated current and the line to ground terminal voltage. Draw the equivalent circuit. • Calculate the induced voltage, E., at rated load and pf = 0.8 lag.

A 3-phase, 50 Hz, 16 pole generator with concentrated windings has 144 slots with 10 conductors per slot. The flux/pole of 24.8 mWb is sinusoidally distributed. The coil is full pitched. Find the line emf.

A generator is connected through a transformer to a synchronous motor as shown in the following figure. (All values in this problem are per unit.) Before the fault V,=0.9,1=1 with power factor 0.8 lagging. jX, P + jX ds jX" dm + E. E The reactances are Xd=0.15 , X,=0.1 , X âm=0.35. A symmetric fault occurs at P. Find the per-unit current magnitudes in the fault, the generator and the motor (a) using subtransient voltages. (b) using a Thevenin equivalent.