I Sing1e phase Transformers : Operation of practical transformer under no-load and on-load with phasor diagrams. Open circuit and Short circuit tests, calculation of equivalent circuit parameters and predetermination of efficiency-commercial and all-day efficiency. Voltage regulation and its significance. Three-phase Transformers : Introduction, Constructional features of three-phase transformers. Choice between single unit three-phase transformer and a bank of three single-phase transformers. Transformer connection for three phase operation-star/star, delta/delta, star/delta, zigzag/star and V/V, comparative features. Phase conversion-Scott connection for three-phase to two-phase conversion. Labelling of three-phase transformer terminals, vector groups. 2 Tests, Parallel Operation of Transformer & Auto Transformer : Polarity test, Sumpner's test, separation of hysteresis and eddy current losses Parallel Operation of Transformers : Necessity of Parallel operation, conditions for parallel operation Single phase and three phase. Load sharing In case of similar and dissimilar transformers. Auto transformers and Tap changing transformers : Introduction to autotransformer - copper economy, equivalent circuit, no load and on load tap changing transformers. 3 Three-Winding Transformers & Cooling of Transformers : Three-winding transformers. Cooling of transformers. Direct current Generator : Armature reaction, Commutation and associated problems, Synchronous Generators : Armature windings, winding factors. e.m.f equation. Harmonics-causes. reduction and elimination. Armature reaction. Synchronous reactance, Equivalent circuit. 4 Synchronous Generators Analysis : Alternator on load. Excitation control for constant terminal voltage. Voltage regulation. Open circuit and short circuit characteristics, Assessment of reactance-short circuit ratio, synchronous reactance, Voltage regulation by EMF. MMF and ZPF. 5 Synchronous Generators (Salient Pole) :
