Kalender

Introduction to electrical machines and drives, course information and study tips

Lecture 1 OH

course information

Operating principle of DC machines, equivalent circuit (comp. chpt 8-8-4)

homework before:

1- Control your pre-requisites by reading handouts Magnetic Circuits and Electromechanical Energy Conversion from  [SEN]. 

2- Go to  Chalmers visualisation program , choose electrical machines and go through "magnetic" and "DC current".

4- Study pages 237-251 (pp1-15 in pdf file of chapter 5) in [LED] .Read beginning of chapter 8 in EJ2200 book, including section 8.4. 

Alt. 4- corresponding contents in [SEN] (chapter 4 pp121-166) and/or [FIT] (chapter 7).

References details are given at https://www.kth.se/social/course/EJ2201/page/other-sources/

DC machines, compensation, variable speed, dynamic model (comp. chpt 8.5-8.7)

homework before

1- Read beginning of chapter 8 in EJ2200 book (again), AND from section 8.5 to end of chapter. 

Alt. corresponding contents in [SEN] (chapter 4 pp167-197) and/or [FIT] (chapter 7 and section 11.1, not covering all in compendium).

Problems 8.4, 8.3, 8.7, 8.12, 8.11

Teachers: Naveed, Rúdi

Induced voltage and winding factor, air gap mmf and three-phase mmf, multiple pole pairs (comp. chpt 3)

Homework before lecture 4 

1- Go to the visualization tool from Chalmers, http://webfiles.portal.chalmers.se/et/Files/elkraft/Engelsk/start/index.html. Select "electric machines". Go to "travelling flux" and vary frequency, current amplitudes and direction. Can you write mathematical equations describing what you see? The answers can be found in reading the course literature. Have a look at the YouTube videos, to see real windings and how they are manufactured (fascinating!)

2- Read book

Alt. 1 course compendium chapter 3, defining the concepts you should understand and the notations we should use to communicate within the course.

Alt.2 [SEN] pp569-578 and pp209-216. No corresponding video lecture  [DEL] :-(

Alt. 3 [FIT] pp188 (202) to pp213 (228).

3- Work on your list of technical terms and notations, checking the new introduced variables and finding their equivalent in your mother language.

Windings

Problems 3.6, 3.1, 3.7, 3.4

Teachers: Naveed, Rúdi

Operating principle of the induction machine, magnetisation and torque production in induction machines, equivalent circuit  (comp. 2-2.4)

Homework before lecture 5 on 22nd Sept @10

1- Reading:

alt. 1 compemdium EJ2200 pages 2-1 to 2.21 (including section 2.6), concentrate on the phenomena described, how the torque, rather than on each single equation. You need to be able to draw the complete equivalent circuit looks like and why the different components are there. Then you can derive most of all the equations from it when you solve problems.

alt. 2 [SEN] chapter 5, sections 5.1 to 5.4 (includes a revision of rotating magnetic field from last week) pp207-220, and section 5.7 pp222-228. Derivation of equivalent circuit easier to follow than compendium but equations 5.37 and 5.39 to 5.43 seem to forget the machine has three phases!

alt. 3 [FIT] chapter 6, pp306-327 (pp321-342 iin pdf file).

 2-  Video DELFT, #6. DC Machine drivers and Induction machines until 56min

If you choose only alt. 1, you do not get any pictures of real induction machines, check YouTube vidoes or open other books on electrical machines. You can not understand machines if you do not know how they look like inside!

Problems 2.1, 2.4, 2.11, 2.10

Teachers: Naveed, Rúdi

Preparation of lab 1 with teacher interaction

homework before the class activity

1- Read the hand-out for lab 1

2- (re)-read chapter 2 (2.1-2.6) and chapter 3 of the compendium EJ2200, if necessary. 

3- Read pages 2-31 to 2-34 (including example) to learn about unbalanced voltages.

Homework after the class activity

Finish the preparatory work and submit a pdf file in course webb (left menu assignment) before 15:00 on Friday the 25th of September.

occasion 1

E2C lab, Teknikringen 33, 1 floor down 

occasion 2

E2C lab, Teknikringen 33, 1 floor down

Induction machines: Leakage inductance, starting, reversing, generator operation (comp. 2-.5-2.8)

Homework before lecture

1- Read compendium EJ2200 pages 2-18 to 2.27 (including sections 2.5 and 2.6 again).

Complement with [SEN] chapter 5, sections 5.5, 5.9 to 5.12  pp233-254. The power flow diagrams are really good!

[FIT] chapter 6 section 6.5-6.8, pp322-347 (pp337-362 in pdf file).

2- Add new variables in your own list of notations (with corresponding words in mother language).

Problems 2.5, 2.12, 2.18, 2.19

Teachers: Naveed, Rúdi

occasion 3

E2C lab, Teknikringen 33, 1 floor down

occasion 4

E2C lab, Teknikringen 33, 1 floor down

occasion 5

E2C lab, Teknikringen 33, 1 floor down

Induction machines: variable working point and variable speed control 

Homework  after tutorial 4 and before lecture 7 

1- Re-do problem(s) done in class and make sure you know how to solve 2.12, 2.18 and 2.19. Solve as well as other problems.

2- Read:

alt. 1 compendium

Revision: starting of IM, sections 2.7.1 and 2.7.2 pp2-21 to 2-24,

New: sections 2.9 to 2.11  pp 2-27 to 2-37 (section 2.11 had to be read for lab 1)

alt. 2 [SEN] sections 5.11 to 5.13 pp 248-270 and chapter 7 about single phase IM section 7.1 is enough, but interesting until section 7.3 (out of scope course though!). OBS nothing about unbalanced voltages in this book so check compendium

alt. 3 [FIT] does not cover all parts of compendium but following pages could be studied (V/f control and field weakening are missing)

pp340-348 rotor resistance, pp201-202 +/- waves of single-phase winding, pp452-455 single-phase IM, pp471-473 unbalanced (diffrent from compendium), pp595-603 rotor and voltage influence on working point

3- Watch [DELFT] lecture 8, slides 17 to 35.

Problems 2.8, 2.14, 2,16

Teachers: Naveed, Rúdi 

solving problems from old exam with teachers available for questions

Juan introduces the project, followed by introduction to Simulink for those who have never used in student room.

DC machines and induction machines

Vector representation of induction machines, dynamics

Vector representation of induction machines and tutorial chapter 4 (problems 4.1 and 4.2) 

Homework before:

1- reproduce derivations of key equations like voltages, power and torque in different reference frames i.e. the ones in the formula sheet EJ2200 about chapter 4, to revise beginning of chapter 4

2- read end of chapter 4 from section 4.8.

Vector control of induction machines

Covers contents of Chapter 5 in compedium  and project

Synchronous machines #1

Homework

1- Read chapter 6 in compendium, section 6.1

2- Complement with

[SEN] chapter 6, sections 6.1 to 6.8

[FIT] chapter 5, pp260-281, watch out with factor 3 not appearing in power equations and read carefully explanation p267

Phasor diagrams 4 cases

problems 6.1, 6.6

Teachers: Tim, Rúdi

Synchronous machines #2

Homework

Read chapter 6 in compendium, (re-read 6.1) sections 6.2 and 6.3 as well appendix C

Complement with 

[SEN] chapter 6, sections 6.9 to 6.13 (not 6.12), 

[FIT] chapter 5, sections 5.6 to 5.9, pp282-296, watch out with factor 3 not appearing in power equations and read carefully explanation p267

Problems 6.2, 6.7, 6.8

Teachers: Rúdi

Time harmonics in induction machines

Before class activity;

1. Watch videos of lecture and problem 7.1 and 7.11 in scalable learning 

2- Read compendium, check chapter 3 again and then chapter 7, sections 7.1, 7.2, 7.3, 7.6 and 7.7

[SEN] chapter 5 induction machines section 5.15 (5.15.2 not in EJ2201) + appendix A pp 569-581 BEWARE! error in sentence at bottom of p575 "these harmonics flux denisties induce harmonics voltages in the windings". The stator space harmonics create  induced voltages at fundamental frequency (n tops per spatial period rotating at w1/n -> fundamental). It is the rotor space harmonics that create time harmonics in the stator windings.

Solve an old exam with teachers in the room to answer questions

Opportunity to ask questions about videos for chapter 4 (lecture and tutorial).

Synchronous machines (chapter 6) and vector representation (chapter 4)