30220334 (Electric Machinery Fundamentals)

Course Name: Electric Machinery Fundamentals

Course Number: 30220334

Program: Undergraduate program

Type: Required

Credits: 4

Term Offered: Spring

Prerequisite(s): Physics, Principles of Electric Circuits

Instructor(s): Xudong Sun, Shanming Wang, Jianyun Chai

Textbook(s):

Xudong Sun, Shanming Wang. Electric machinery. Tsinghua University Press, 2006. (in Chinese)

Reference(s):

A. E. Fitzgerald, C. Kingsley, S. D. Umans. Electric machinery (6th Edition). McGraw-Hill, 2003.

S. J. Chapman. Electric machinery fundamentals (4th Edition). McGraw-Hill Higher Education, 2005.

S. J. Chapman. Electric machinery and power system fundamentals. McGraw-Hill, 2002.

T. Wildi. Electrical machines, drives, and power systems (6th Edition). Prentice Hall, 2006.

M. E. El-Hawary. Principles of electric machines with power electronic applications (2nd Edition). IEEE Press, 2002.

Xudong Sun, Shanming Wang. A study guide to electric machinery. Tsinghua University Press, 2007. (in Chinese)

Qiansheng Hu, Minqiang Hu. Electric machinery (2nd Edition). China Electric Power Press, 2009. (in Chinese)

Chenglin Gu, Qiaofu Chen, Yongqian Xiong. Electric machinery (2nd Edition). Huazhong University of Science and Technology Press, 2005. (in Chinese)

Course Description:

     The course is about the foundation of the theory and analysis methods of electric machinery, key terminologies of electric engineering, and some substantial ideas as electrical engineers. It covers the basic electromagnetic principles of transformers and typical rotating machinery including both AC and DC machines, together with their steady-state performances. The basic concepts, theories and analysis methods are introduced in-depth. A good grasp of the basic knowledge of electric machinery and the ability to apply it to solve relevant problems are emphasized.

Course Objectives and Outcomes:

The chief objective of the courses is to build a strong foundation in the basic principles of electric machinery. Its emphasis has been on analytical techniques and ability in the areas of electric machinery and electric engineering.

Mastery of the material covered in the courses combined with the laboratory sessions should prepare individuals in the electric machinery area with adequate prerequisite foundation for proceeding on to elective undergraduate and more advanced graduate courses in power systems, and electric machinery design and control.

The course should enable the students to do the following upon completion of it. Numbers in brackets are linked to department educational outcomes.

1.Understand the electromagnetic and mechanical fundamentals such as force, torque, power, Ampere’s Law, Faraday’s Law, magnetic circuit, understand the operational fundamentals of basic transformers and rotating AC and DC machines and their connection, and thus raise the ability to apply basic electromagnetic theories to practice. [1]

2.Gain working knowledge of the theories of the practical transformers and rotating machines, their equivalent circuit models and basic test methods, and the contemporary engineering aspects of practical electric machine performance, operation and electromagnetic design. [1, 2, 3, 5, 10]

3.Skillfully master the methods for analyzing typical electric machines, and have the ability to apply them to solve the problems arising from engineering reality. [5]

4.Be familiar with various intuitive ideas in electrical engineering, e.g. equivalent transform perspective, abstract perspective, and engineering approximation perspective. [3, 5, 11]

5.Be familiar with a certain number of terminologies, which will be used repeatedly in the successive learning and studying. [5]

Course Topics:

1.Introduction to the applications of electric machines. The concept of electric machine. The basic laws applied to electric machinery.

2.Transformers: basic physical structure, rating, analysis of no-load and load steady operation, equivalent circuits and engineering aspects of transformer analysis, open-circuit test and short-circuit test, per unit system, performance.

3.Three-phase transformers: magnetic circuit construction and winding connection, parallel operation.

4.Basic principles of AC machines: elementary concepts, introduction to AC machines.

5.AC windings: concentrated and distributed windings, EMF generated in AC windings, pulsating MMF and rotating MMF.

6.Synchronous machines: type, applications, basic physical structure and rating, analysis of no-load operation and load operation, armature reaction, two-reaction theory, reactances and equivalent circuits of non-salient and salient machines, vector diagram and phasor diagram, open- and short-circuit characteristics, steady-state operating characteristics, power-angle characteristics, parallel operation and regulation of active and reactive power, synchronous motor.

7.Induction machines: type, applications, basic physical structure and rating, analysis of steady-state operation, vector diagram and phasor diagram, equivalent circuit, parameter determination from no-load and blocked-rotor tests, power equation, electromagnetic torque and torque equation, speed-torque characteristics of induction motors, effect of rotor resistance, starting, braking and speed control of induction motors, induction generators.

8.DC machines: basic principle, basic physical structure and rating, features of armature windings, magnetic field and magnetic circuit, armature reaction and commutation, induced EMF and electromagnetic torque, analysis of steady-state performance, steady-state operating characteristics, starting, braking and speed control of DC motors.

9.Engineering aspects of practical electric machine performance and operation, such as losses, rating and heating, efficiency, power factor.

Experiment(s): Offered by another course “Experiments for Electric Machinery” (30220351)

Project(s):

The projects are optional, besides the common requirements of the course. They are designed for the students who want to study in depth and further develop the ability to analyze and solve practical problems.

Four projects are presented to the students in sequence, which cover the problems in transformers, AC windings, synchronous machines and induction machines, respectively. An oral exam is held for an individual student who completes the project to qualify him/her for the next project. Usually different projects are given in three successive years.

Some examples of the projects are as follows:

Analysis of the harmonics in the currents and EMFs of a three-phase transformer bank, considering magnetic saturation

 Understand the concept of harmonics generated in EMFs and currents of the primary and secondary windings, utilize adequate methods to analyze the problem, and design a flow chart for calculating the harmonics with circuit simulation software.

Scheme design of a multiphase AC winding

 Use the theories of AC windings and their EMF and MMF to analyze the EMF and MMF of a set of AC windings for a 12 phase synchronous machine, solve the basic design problem and present the optimum scheme for suppressing harmonics.

Analysis of a three phase induction motor in fault

 For an induction motor while an open-phase fault occurs, utilize the relevant theories and methods to develop its equivalent circuit and torque-speed characteristics, solve the problems such as variation in its parameters and torques, and the effects of harmonics.

Course Assessment:

       Homework measures, 20 points.

       Mid-term exam score, 30 points.

       Final exam score, 50 points.