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:
Bimbhra P.S., “Electrical Machineryâ€, R.C. Khanna & Vineet Khanna, Khanna Publishers, 1st Edition, 2021. Fitzgerald. A.E., Charles Kingsely Jr, Stephen D.Umans, “Electric Machineryâ€, Tata McGraw Hill Books Company, 6th Edition, 2017. Stephen D. Umans, “Fitzgerald & Kingsley's Electric Machineryâ€, McGraw Hill Education India Limited, 7th Edition, 2020. Deshpande M. V., “Electrical Machinesâ€, PHI Learning Pvt. Ltd., New Delhi, 2018. Theordore Wildi, “Electrical Machines, Drives and Power Systemsâ€, Pearson India Education, 2023. Ashfaq Husain, Harroon Ashfaq, “Electric Machines Paperbackâ€, Dhanpat Rai & Co, 3rd Edition, 2020.
Text Book:
Nagrath I. J., Kothari D. P. “Electric Machinesâ€, Tata McGraw Hill Publishing Company Ltd, 5th Edition, 2018. (UNIT I-V) Murugesh Kumar, K., “D.C Machines and Transformers†Vikas publishing house private limited, New Delhi, 9th Reprint, 2014. (UNIT I-V)
