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.
Text Book:
Nagrath I. J and Kothari D. P. “Electric Machines”, Fourth Edition, Tata McGraw Hill Publishing Company Ltd, 2016. (UNIT I-V) K.Murugesh Kumar, “D.C Machines and Transformers” Vikas publishing house private limited ,New Delhi. 2014. (UNIT I-V)