Course detail

Electrical Machines

FEKT-BKC-ESBAcad. year: 2022/2023

The basic laws and equations used in the theory of electrical machines. Magnetic circuits of electrical machines. The basic voltage equations, equivalent circuit diagrams, phasor diagrams, the basic electrical connections of electrical machines. Energy and power flow diagrams, losses and efficiency. Torque equation. Electrical machines' performance. Nonsymmetrical loading. Influence of higher harmonics. Basic characteristics of electrical machines.

Language of instruction

Czech

Number of ECTS credits

6

Mode of study

Not applicable.

Guarantor

doc. Ing. Jan Bárta, Ph.D.

Department

Department of Power Electrical and Electronic Engineering (UVEE)

Learning outcomes of the course unit

Subject graduate should have been able:
- describe main parts of electric machines,
- know classes of insulation and electrical machines costruction,
- describe construction of transformer,
- explain transformer losses,
- understand and explain single and multiphase transformer operation,
- calculate parameters of transformer equivalent circuit from no-load and short – circuit tests,
- draw and explain phasor diagrams of transformer at no load, at short circuit and generally loaded.
- transformer winding connection and phasor diagram for different hour angle,
- explain and calculate transformer voltage regulation,
- describe and explain construction and principle of operation of induction machine with wound rotor and with squirrel cage,
- describe revolving magnetic field generation,
- define basic kinds of AC machine windings,
- sketch curve of magnetic field of AC winding distributed in more slots,
- draw equivalent induction machine circuit diagram, derive torque equation and draw torque - speed characteristic ,
- describe connection of induction motor into public utility network and speed control,
- describe construction and principle of operation of single phase induction motor,
- describe principle operation and construction of nonsalient synchronous machine,
- draw simplified circuit diagram, derive torque equation and draw phasor diagram,
- explain synchronous generator operation with isolated load and with public utility network, use phasor diagram for explanation,
- explain synchronous compensator principle of operation,
- describe DC machine construction and principle of operation,
- describe basic types of DC machine windings,
- derive torque and induced voltage equations,
- explain properties of DC motors and generators,
- describe construction and explain principle of operation of AC single phase commutator machines.

Prerequisites

Student should have been able to:
-explain and define basic terms magnetic field, electric field, magnetic field, circuits with lumped and distributed parameters,
- solve DC, AC and magnetic circuits,
- solve three phase AC circuits,
- define the terms work and energy,
- describe and explain basic properties soft and hard magnetic materials.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

Teaching methods depend on the type of course unit as specified in the article 7 of BUT Rules for Studies and Examinations.

Assesment methods and criteria linked to learning outcomes

Control tests - 20 points
Laboratory and computer exercises - 15 points
Final Exam - 65 points

Course curriculum

1. Introduction, motivation, repetition of the basics of magnetism and solving magnetic circuits.
2. Transformers. Ideal transformer, real transformer, basic equations.
3. Principle of operation and design of power transformers.
4. Three-phase transformers, winding connection, parallel operation.
5. Magnetic circuit and windings of rotating electrical machines. Principle of operation of asynchronous machine, generation of rotating field.
6. Equivalent circuit, basic equations and moment characteristics.
7. Starting three-phase asynchronous motors from the mains, speed control.
8. Single-phase asynchronous motor. Three-phase asynchronous motor on single-phase network.
9. Synchronous machine. Principle of operation, design.
10. Theory of non-salient pole machine. Torque characteristics, synchronous machine operating into independent load and in parallel with the network.
11. Synchronous machines with salient poles and permanent magnets.
12. DC machines. Principle of operation and design, derivation of basic equations.
13. Operating characteristics of DC machines in steady state.
 

Work placements

Not applicable.

Aims

To acquaint the students with the principle of operation and performance of transformers, induction machines, DC machines and synchronous machines. The theoretical knowledge are proved in laboratory excerscises

Specification of controlled education, way of implementation and compensation for absences

The content and forms of instruction in the evaluated course are specified by a regulation issued by the lecturer responsible for the course and updated for every academic year.

Recommended optional programme components

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

Fitzgerald,Kingsley,Kusko::Electric Machinery,McGraw-Hill
Měřička,Haňka,Voženílek.::Elektrické stroje,ČVUT Praha
O'Kelly:Performance and Control of Electrical Machines,McGraw-Hill

Recommended reading

Not applicable.

Classification of course in study plans

  • Programme BKC-SEE Bachelor's 2 year of study, summer semester, compulsory

Type of course unit

 

Lecture

39 hod., optionally

Teacher / Lecturer

doc. Ing. Jan Bárta, Ph.D.

Syllabus

1. Basic laws of electromagnetism related to electrical machines.
2. Principle of electromechanical energy conversion.
3. Transformers. Ideal transformer, actual transformer, basic equations.
4. Principle of operation and construction of power transformers.
5. Three-phase transformers, winding connection, parallel operation.
6. Magnetic circuit and winding of electrical machines.Principle of operation of induction machine, generation of revolving magnetic field.
7. Equivalent circuit diagram, fundamental equations and torque characteristics.
8. Starting of induction machines speed control.
9. Single-phase induction machine. Three-phase induction machine in single-phase mains. The higher harmonics influence.
10. Synchronous machine. Principle of operation and construction.
11. Theory of nonsalient machine. Torque characteristic, synchronous machine with individual load and parallel operation.
12. DC machines. Principle of operation and construction, fundamental equations.
13. DC machines steady -state performance.

Laboratory exercise

26 hod., compulsory

Teacher / Lecturer

doc. Ing. Jan Bárta, Ph.D.

Syllabus

1. Safety considerations.
2. The main parts of rotary electrical machines. Assembly and disassembly of electrical machines.
3. No load a short circuit transformer test.
4. Winding connection. Load test a efficiency, measurement of a transformer.
5. Three-phase induction motor. Winding connection. No load and blocked rotor test. Induction motor parametr determination.
6. Measurement of induction motor torque charakteric.
7. Induction motor starting.
8. Synchronous machine parallel operating with mains.
9. Measurement of torque characteristics.
10. Parametr determination of synchronous machine with salient poles and with nonsalient rotor.
11. DC machine. No load test. Selfexcitation of shunt generator.
12. Connection of DC motor to mains. Speed control characteristics of DC motors.
13. Evalation.