Introduction to Power System
Subject Code: EPM3046
Aim of Subject: To introduce the basic concepts of electric power systems, in particular discuss the operation, control and protection of power systems.
Learning Outcome of Subject: At the completion of the subject, students should be able to:
  • Understand the basics of various types of electric power generation plants.
  • Apply the basics of real, reactive and complex powers in single-phase and three-phase systems.
  • Analyse three-phase balanced systems.
  • Use the basics of inductance and capacitance and apply them in single-phase and three-phase transmission lines.
  • Perform power flow calculations for short, medium and long transmission lines.
  • Derive bus admittance and bus impedance matrices for a given power system network and perform power flow analysis using Gauss-Seidal method.
  • Calculate symmetrical fault currents in a simple power system.
  • Appreciate the basics of power system protection, grounding practice in power systems and the operating principles of overcurrent relays.
  • Do simple calculations based on the basics of electrical installation in buildings and the operating principles of various substation components.
Programme Outcomes:
  • Ability to acquire and apply fundamental principles of science and engineering(40%)
  • Capability to communicate effectively(5%)
  • Acquisition of technical competence in specialised areas of engineering discipline(5%)
  • Ability to identify, formulate and model problems and find engineering solutions based on a systems approach(10%)
  • Ability to conduct research in chosen fields of engineering(5%)
  • Understanding of the importance of sustainability and cost-effectiveness in design and development of engineering solutions(5%)
  • Understanding and commitment to professional and ethical responsibilities(5%)
  • Ability to work independently as well as with others in a team(10%)
  • Ability to be a multi-skilled engineer with good technical knowledge, management, leadership and entrepreneurship skills(5%)
  • Awareness of the social, cultural, global and environmental responsibilities as an engineer(5%)
  • Capability and enthusiasm for self-improvement through continuous professional development and life-long learning(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(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: ECT1016: Circuit Theory
  • Hadi Saadat, "Power System Analysis", WCB/McGraw-Hill, 1999. (Textbook)
  • T. Wildi, "Electrical Machines, drives and power systems", Prentice-Hall, 1997.
  • J.J. Grainger and W. D. Stevenson, Jr. "Power System Analysis", McGraw-Hill, 1994.

Subject Contents

  • Introduction to Power System

  • Generation of electrical power: Various types of conventional and non-conventional generation plants. Power, reactive power and complex power. Single-phase and three-phase power calculations. Analysis of three-phase balanced circuits. Per-unit quantities, Single-line diagram and impedance diagram of power systems. Simple models of generators and transformers.
  • Transmission Lines

  • Calculation of inductances of single-phase and three-phase lines. GMR and GMD. Bundled conductors. Calculation of capacitance of single-phase and three-phase lines. Current and voltage relations: Short, medium and long lines. Power-flow through short and medium lines.
  • Network Equations and Calculations

  • Representation of power system components. Derivations of bus admittance and bus impedance matrices.
  • Introduction to Power-flow Analysis

  • Power-flow equations. Power-flow solution using Guess-seidel method.
  • Symmetrical Fault Calculations

  • Types of faults, fault calculations, fault levels. Circuit breaker ratings. Means of reducing fault currents.
  • Basic Protection

  • Objective and approach of power system protection. Basic principles and components of protection including fuses. Operating principles of overcurrent relays. Instantaneous and time grading relays. Safety grounding, Grounding practice in power systems.
  • Distribution System

  • Substations: Substation components, circuit breakers, air-break switches, disconnect switches, Medium-voltage and low-voltage distribution, Grounding electrical installation, electric shock, electrical installation in buildings.


1. Power-Flow Through Transmission Lines
2. Power-Flow analysis