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Electrical Machines (EE3283)
Prerequisite(s)
Basic Electronics (EE2223)
Recommended Book(s)
Electric Machinery Fundamentals by Stephan J. Chapman, 4^{th} Ed.
Reference Book(s)
Electric Machines by Charles I. Hubert
Course Objectives
The main focus of this course is to understand the magnetic field, the reluctance of magnetic materials and air. The voltagecurrent characteristics, voltage regulation of DC generators, torque speed characteristics, speed regulation of DC motors and the generalized concepts of electromechanical energy conversion are included mainly in this course. Working principles, construction and operation of single phase and three phase transformers will be studied. This course includes AC machines fundamentals and production of rotating magnetic field. In this course working principles, construction, characteristics and equivalent circuit of three phase synchronous generators, synchronous motors and induction motors, Single phase and special purpose motors are discussed in detail.
Course Learning Outcomes (CLO)
CLO 1: Explain operating principles of fundamental components of Electric Machines: motors, generators and transformers including synchronous, asynchronous, DC and special purpose motors, AC, DC generators and autotransformers, CTs, PTs, stepup and stepdown transformers. (Level: C2)
CLO 2: Examine the magnetic field, reluctance of magnetic materials, flux and mmf in magnetic circuits and perform transformer analysis using standard testing procedures including opencircuit & shortcircuit tests, voltage regulation, efficiency and circuit analysis involving transformers. (Level: C4)
CLO 3: Examine construction, working principles, characteristics and equivalent circuit of three phase synchronous generators, synchronous motors and induction motors, Single phase induction and special purpose motors. (Level: C4)
CLO 4: Analyze voltagecurrent characteristics, commutation of DC generators, torque speed characteristics and speed regulation of DC motors. (Level: C4)
Course Contents
DC Machines Topics
Introduction to Machinery Principles
 Rotational motion
 Newton’s Law and power relationships
 The Magnetic field
 Magnetic Circuit with air gap
 Faraday’s law
 Production of induced force on wire
 Induced voltage on a conductor moving in a magnetic field
 Linear DC machine
DC Machinery Fundamentals
 Simple rotating loop between curved pole faces
 Commutation
 Construction
 Simple armature winding
 Armature reaction
 Interpoles, compensating winding and brush shifting
 Internal generated voltage and induced torque equations of real machines
DC Generators
 Introduction
 Voltage regulation
 Magnetization curve
 Equivalent circuits
 Working and characteristics of separately excited, shunt, series and compounded generators
 Parallel operations of direct current generators
DC Motors
 Introduction
 Speed regulation
 Equivalent Circuits
 Working and Characteristics of separately excited, Shunt and Permanent magnet
 Working and Characteristics of series and compounded motors
 Torque–speed Equations
 Efficiency calculations
 Stepper Motor and Drive circuit
AC Machines Topics
Transformer Fundamentals
 Importance of transformers
 Types and construction
 The ideal transformer
 Leakage reactance
 Theory and operation of single phase transformer
 Losses and phasor diagram
 The equivalent circuit of a real transformer
 No load and short circuit test
 The per unit system
 The transformer voltage regulation and efficiency
 Tapping the autotransformer
 Three phase Transformers
 Construction of power Transformer
 Three phase connections and harmonics suppression
 Vector groups
 Three phase transformer using two transformers
 Transformer ratings and related problems
AC Machines Fundamentals
 A simple loop in a uniform magnetic field
 Review of three phase generation
 The rotating magnetic field
 The relationship between electrical and mechanical degree
 The relationship between electrical frequency and the speed of the magnetic field rotation Induced voltage and induced torque
 Losses and power flow diagram
 Voltage regulation and speed regulation
Synchronous Generator
 Construction
 Excitation system
 Equivalent circuit of Synchronous Generator
 Phasor diagram, Power & Torque
 Measurement of model parameters
 Effect of load changes on a generator
 Parallel operation of generators
Synchronous Motor
 Basic principle of motor operation
 Equivalent circuit
 Torque speed characteristics
 Power and torque equation
 Phasor diagram
 The effects of load change, and field current change
 Vcurves of synchronous motor & power factor correction
 Starting of synchronous motor
 Synchronous motor ratings
Three Phase Induction Motor
 Construction
 Basic concepts and working principles
 Synchronous speed
 Slip and its effect on rotor frequency and rotor voltage
 Equivalent circuit
 Power and torque
 Torque speed characteristics
 losses, efficiency and power factor
Single Phase and Special Purpose Motors
 The Universal motor
 Introduction to single phase induction motor
 Starting single phase induction motors
 Split phase windings
 Capacitor start motor
 Permanent split capacitor motor
 Capacitor start and capacitor run motors
 Shaded pole motors
 Reluctance motors
 The Hysteresis motor
Mapping of CLOs to Program Learning Outcomes
CLOs/PLOs 
CLO:1 
CLO:2 
CLO:3 
CLO:4 
PLO:1 (Engineering Knowledge) 
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PLO:2 (Problem Analysis) 

√ 
√ 
√ 
PLO:3 (Design and Development of Solutions) 




PLO:4 (Investigation) 




PLO:5 (Modern Tool Usage) 




PLO:6 (The Engineer and Society) 




PLO:7 (Environment and Sustainability) 




PLO:8 (Ethics) 




PLO:9 (Individual and Team Work) 




PLO:10 (Communication) 




PLO:11 (Project Management) 




PLO:12 (Life Long Learning) 



