Course Details

Subject {L-T-P / C} : EE2001 : Electrical Machines - I {3-1-0 / 4}
Subject Nature : Theory
Coordinator : Dr. Shubhobrata Rudra


A brief recapitulation of single-phase transformer working principle, different types of tests for determining parameters and specification of a single-phase transformer, a thorough analysis of the harmonics of a single-phase transformer, 3-phase transformers – types – phasor groups. Effects of unbalanced loading, generation of harmonics by
transformers and their suppression, 3-phase to 2-phase and 3-phase to multiphase transformation. 3-winding transformers – parameters estimation, voltage regulation – applications. Parallel operation of transformers. Autotransformers, Analysis of harmonics in a three-phase transformer. ( 15L)

DC Machine:
  A brief recapitulation of the working principle of dc machines,  a detailed discussion on the armature reaction and compensation of the same, Basic starting and speed control scheme of DC motors. (5L)
Mid-sem Exam
Electro-Mechanical Energy conversion Principle: Forces and Torques in MagneticField Systems, Energy Balance, Energy in the Singly-Excited Magnetic FieldSystems, Determination of Magnetic Force and Torquefrom Energy, Determination of Magnetic Force and Torquefrom Conery, Multiply-Excited Magnetic FieldSystems,Forces and Torques in Systems withPermanent Magnets (4L)
Fundamental Theory of Rotating Machines:EMF of Elementary Alternator, Relation between PolarFlux and Airgap Flux Density,  EMF ofElementary Multipolar Alternator, Frequency of Alternation, Factors Affectingthe Induced EMF, Fourier Analysis of Airgap Flux Density and MMF Distribution,Armature Windings, Fractional-pitch Windings, Fractional-slot Windings, InducedEMF in Full-pitch Distributed Windings, Induced EMF in Fractional-pitchWindings, Wave Form of EMF, Nonsinusoidal Field Distribution, Tooth Ripples. Skewing of Slots, Armature Reaction, MMF of Armature Reaction, TheRotating Magnetic Field, Effect of Distributed and Fractional-pitch Windings onArmature Reaction, Space Harmonics of MMF. Travelling Waves of MMF Due to TimeHarmonics, Resolution of Travelling Waves into Standing Waves (16L)

Course Objectives

  1. To Present an insightful concise yet comprehensive discussion of the single and three-phase transformers.
  2. To discuss the details of armature reaction and compensation techniques,
  3. To explain the fundamental concepts of energy conversion
  4. To discuss the design details and fundamentals of Rotating machine

Course Outcomes

After attending the course the students should be able to:
Interconnect different single-phase transformers with multiple tap-setting to realize any balanced multiphase supply, and also recommend a connection pattern to accomplish desired harmonics elimination
Determine the cause responsible for the deterioration in a given DC machine performance
Carry out the energy flow analysis in any given electromechanical systems,
Understand the constructional details of any rotating and linear machine, and recommend a particular winding specialization to achieve a desired harmonic attenuation/elimination.

Essential Reading

  1. Alexandar S Langsdorf, Theory of Alternating Current Machinery, McGrawhill
  2. A.E. Fitzgerald, C. Kingsley, S.D. Umans, Electric Machinery, McGrawhill

Supplementary Reading

  1. D.C. White and H.H.Woodson, Electromechanical Energy Conversion, John Wiley and Sons
  2. M. G. Say, The Performance and Design of Alternating Current Machines, CBS publications

Journal and Conferences

  1. IEEE Transaction on Energy Conversion
  2. Cigre Annual Conference