
Introduction
to Machines
Subject Code: 
EPM1026 
Aim of Subject: 
To introduce the basic concepts, general operating
principles and construction
of electrical machines. 
Learning Outcome of Subject: 
At the completion of the subject, students should be
able to:
 Recognize the fundamental principles of electrical
machines and threephase systems.
 Explain the construction, operation and applications
of various generators, motors and transformers.
 Distinguish the constructional details of induction
machines and synchronous machines.
 Construct the equivalent circuits and phasor diagrams
for transformers and induction motors.
 Analyse the torquespeed characteristics of
threephase induction motors.

Programme Outcomes: 
 Ability to acquire and apply fundamental principles
of science and engineering. (60%)
 Capability to communicate effectively. (10%)
 Acquisition of technical competence in specialised
areas of engineering discipline. (10%)
 Ability to identify, formulate and model problems and
find engineering solutions based on a systems approach. (10%)
 Understanding and commitment to professional and
ethical responsibilities. (5%)
 Ability to work effectively as an individual, and as
a member/leader in a team. (5%)

Assessment Scheme: 
 Lab Experiments  work in group of 2, lab report
writing, oral assessment at the end of lab(10%)
 Tutorial / Assignment  group assignment, focus group
discussion at tutorial, to enhance understanding of basic concepts in
lecture(10%)
 Test Quiz  written exam(20%)
 Final Exam  written exam(60%)

Teaching and Learning Activities: 
53 hours (lectures, tutorials and laboratory
experiments) 
Credit Hours: 
3 
PreRequisite: 
ECT1016: Circuit Theory and
ECT1026: Field Theory 
References: 
 S. J. Chapman, "Electric Machinery Fundamentals" –
4th edition, McGraw Hill Higher Education, 2004. (Textbook)
 B.S. Guru and H.R. Hiziroglu, "Electric Machinery and
Transformers"3rd edition, Oxford University Press, 2001.
 T. Wildi, "Electrical Machines, Drives, and Power
Systems"5th edition, Prentice Hall, 2002.
 P.C. Sen, "Principle of Electric Machines and Power
Electronics"2nd edition, John Wiley & Sons, 1997.

Subject Contents

Introduction to Machinery Principles
Introduction to electrical machines and transformers. Rotational
motion,
Newton's law, and power relationships. Magnetic field, Fraday’s law,
induced
voltage on a conductor moving in a magnetic field, production of force
on a wire in a magnetic field.
 Threephase Circuits
Threephase systems. Relation between line and phase quantities.
Analysis of Balanced threephase circuits. Y? transformation. Power
and reactive power calculations.
 D.C. Machines
Principles of operation and construction of DC machines, simple
armature
windings: lap and wave. Emf equation and principle of commutation. DC
generators:
Separately excited, shunt wound, series wound and compound wound
generators.
Conditions for selfexcitation of shuntgenerator. Load characteristics
and voltage regulation. DC motors: Torque equation, characteristics of
shunt, series and compound motors. Starting and speed control. Tests,
measurement
and efficiencies of DC machines.
 Transformers
Singlephase transformers: Construction, principle of operation and
equivalent circuit, phasor diagram, efficiency and regulation. Short
and
open circuit tests. Parallel operation. Three phase transformers:
Construction,
Connections, and Parallel operation Autotransformers, Instrument
transformers.
 Induction Machines
Principles of operation and construction of threephase induction
motor. Slip equation, equivalent circuit, determination of equivalent
circuit parameters by noload and blockedrotor tests. Losses,
efficiency and torque. Torquespeed characteristics, starting torque
and maximum torque. Starting methods. Introduction to singlephase
induction motors.
 Synchronous Machines
Principle of operation of Synchronous generators, Synchronous impedance
and equivalent circuit. Shortcircuit and opencircuit tests. Voltage
regulation. Synchronizing procedures and parallel operation of
synchronous machines. Principle of operation of synchronous motors,
starting methods.
Laboratory
1. Load Test on DC Motors
2. Single Phase Transformer
