Constructional features of a DC machines – Principles of operation of DC generator – EMF equation –Types – methods of excitation – no load and load characteristics of DC generators –armature reaction and commutation.
Principles of operation of DC motor, back EMF – torque equation –Types –characteristics of DC motors – starting methods – speed control
Losses and efficiency – Testing of DC machines- Brake test, Swinburne’s and Hopkinson’s tests – Applications of DC Machines
Principles of operation – constructional features of single phase and three phase transformers – EMF equation – transformer on no load and load – effects of resistance and leakage reactance of the windings – phasor diagram – equivalent circuit – regulation
Losses and efficiency – all day efficiency – testing using design thinking – polarity test – open circuit and short circuit tests –Auto transformer –three phase transformers connections – Tap changing. Applications: Instrument, Isolation, Distribution and Power Transformers.
Reference Book:
P. C. Sen., “Principles of Electrical Machines and Power Electronics”, John Wiley & Sons, 1997 . Syed A. Nasar, “Electric Machines and Power Systems: Volume I”, Mcgraw-Hill College; International Edition, January 1995. Deshpande M. V., “Electrical Machines” PHI Learning Pvt. Ltd., New Delhi, 2018. P.S. Bimbhra, “Electrical Machinery”, Khanna Publishers, 2013. Fitzgerald. A.E., Charles Kingsely Jr, Stephen D.Umans, “Electric Machinery”, Sixth edition, Tata McGraw Hill Books Company, 2016.
Text Book:
Nagrath I. J and Kothari D. P. “Electric Machines”, Fourth Edition, Tata McGraw Hill Publishing Company Ltd, 2016. (UNIT I-V)