Electrical Technology III
 
 
Subject Code: EET2186
Aim of Subject: To provide the students with basic understanding of electrical technology.
Learning Outcome of Subject: At the completion of the subject, students should be able to:
  • understand the principles and construction of DC Machines, Transformers, Induction Machines and Synchronous Machines.
  • calculate the speed, torque, power, efficiency etc. of DC, induction and synchronous machines.
  • compare the functionality of single-phase and three-phase transformers.
  • understand the equivalent circuit model of machines and transfomers.
  • select suitable machines for various applications.
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%)
  • Ability to work independently as well as with others in a team(10%)
Assessment Scheme:
  • Lab Experiments - work in group of 2,lab report writing(10%)
  • Tutorial / Assignment - group assignment,to enhance understanding of basic concepts in lecture(15%)
  • Test/Quiz - written exam(15%)
  • Final Exam - written exam(60%)
Teaching and Learning Activities : 53 hours (lectures,tutorials and laboratory experiments)
Credit Hours: 3
Pre-Requisite: EET1176 Electrical Technology II
References:
  • Electrical Machines, Drives and Power Systems, T. Wildi, Prentice Hall (Textbook)
  • Advanced Electrical Technology by H. Cotton
  • Principles of Electrical Machines and power electronics by PC Sen

Subject Contents

  • Introduction to D.C. Machines (11 hours)
    Principles and construction of D.C. machines. Simple armature windings and E.M.F. equation. Armature reaction and commutation. D.C. generators: excitation and load characteristics of separately-excited, shunt-wound, series-wound and compound-wound generators. Critical resistance. Voltage regulations. D.C. motors: speed and torque. Starting and control. Testing, measurements and efficiencies of D.C. machines.
     
  • Transformers (10 hours)
    Single-phase 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 (10 hours)
    Three-phase induction motor: Production of rotating magnetic field. Principle of action and construction of motor. Slip. Equivalent circuit, losses and efficiency. Winding resistance, reactance and torque. Output characteristics, starting torque and maximum torque. Starting method. Tests and efficiency. Equivalent circuit and measurement of equivalent circuit components. Power, torque and slip equations. Starting and braking of induction motors.
     
  • Synchronous Machines (9 hours)
    Equivalent circuit, voltage regulation, short circuit and open circuit tests. Power chart and operation unit. Principle of operation. Starting procedures. Load characteristics. Torque and power equation. Constant power lines.
      
     

Laboratory

Experiment 1: Characteristics of DC motors.
Experiment 2: Single phase transformer.
Experiment 3: Induction Machines.