1. Thyristor-Switched Series Reactor (TSSR) for power factor improvement

Eo(LL) (V) a) 3000 b) 2500 2000 1500 1000 500 0 No-load excitation curve @3600rpm 0 1 2 3 4 5 6 DC Excitation current (A) 7 The figure above shows the no-load excitation (LL) curve of a 3-ph, 2-pole, 60 Hz, 1000 kVA, 2.3 kV synchronous alternator at rated speed. The alternator has negligible resistance and Synchronous Reactance Xs = 1.2 n/phase. If the alternator is synchronized to the Power Grid at 2.3 kV (Line to Line), calculate the following: 8 9 10 The value of excitation current required for full load current at 0.7 pf lagging (over-excited). |EO(LL)I IF The alternator current and reactive power when it is delivering 80% rated power (0.8 MW) and its DC excitation current is 4 A. IL Q3ph

A transformer on no-load has a core-loss of 20 W, draws a current of 1 A (rms) and has an induced emf of 110 V (rms). a) Determine the no-load power factor, b) Determine the core-loss current and magnetizing current. c) Draw the phasor relationship of induced emf, flux and exciting current. d) Calculate the no-load circuit parameters G; and Bm of the transformer. e) Draw the circuit model of transformer on no-load (exciting current). Secondary terminals N1 N2 e2 open Secondary Primary Core (magnetic material)

A 3Ø, Y-connected alternator is rated at 1,600KVA, 13.5KVv. The armature effective AC resistance per phase is 1.50. The percentage regulation for a load of 1,280kW at unity power factor is 3.5%. Determine: (a) synchronous reactance of the alternator (b) %VR at full-load 0.8pf leading (c) What is the effect on %VR value if taken at half-load lagging pf? Justify and explain briefly your answer on one(1) sentence.