|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
- Recognize the fundamental principles of electrical
machines and three-phase 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 torque-speed characteristics of
three-phase induction motors.
- 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
- Test Quiz - written exam(20%)
- Final Exam - written exam(60%)
|Teaching and Learning Activities:
||53 hours (lectures, tutorials and laboratory
||ECT1016: Circuit Theory and
ECT1026: Field Theory
- 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.
Introduction to Machinery Principles
Introduction to electrical machines and transformers. Rotational
Newton's law, and power relationships. Magnetic field, Fraday’s law,
voltage on a conductor moving in a magnetic field, production of force
on a wire in a magnetic field.
- Three-phase Circuits
Three-phase systems. Relation between line and phase quantities.
Analysis of Balanced three-phase circuits. Y-? transformation. Power
and reactive power calculations.
- D.C. Machines
Principles of operation and construction of DC machines, simple
windings: lap and wave. Emf equation and principle of commutation. DC
Separately excited, shunt wound, series wound and compound wound
Conditions for self-excitation of shunt-generator. Load characteristics
and voltage regulation. DC motors: Torque equation, characteristics of
shunt, series and compound motors. Starting and speed control. Tests,
and efficiencies of DC machines.
Single-phase transformers: Construction, principle of operation and
equivalent circuit, phasor diagram, efficiency and regulation. Short
open circuit tests. Parallel operation. Three phase transformers:
Connections, and Parallel operation Autotransformers, Instrument
- Induction Machines
Principles of operation and construction of three-phase induction
motor. Slip equation, equivalent circuit, determination of equivalent
circuit parameters by no-load and blocked-rotor tests. Losses,
efficiency and torque. Torque-speed characteristics, starting torque
and maximum torque. Starting methods. Introduction to single-phase
- Synchronous Machines
Principle of operation of Synchronous generators, Synchronous impedance
and equivalent circuit. Short-circuit and open-circuit tests. Voltage
regulation. Synchronizing procedures and parallel operation of
synchronous machines. Principle of operation of synchronous motors,
1. Load Test on DC Motors
2. Single Phase Transformer