EJ2221 Design of Permanent Magnet Synchronous Machines 7.5 credits

Konstruktion av permanentmagnetiserade synkronmaskiner

The aim of the course is to understand how to make an electromagnetic and thermal design of permanent magnet synchronous machines from any given set of specifications. The knowledge is applied by designing a machine for an industrial application.

  • Education cycle

    Second cycle
  • Main field of study

    Electrical Engineering
  • Grading scale

    A, B, C, D, E, FX, F

Information for research students about course offerings

PhD students are recommended to apply to FEJ3221, given every year in parallel with EJ2221. Take contact with course responsible.

Intended learning outcomes

After the course, the student should be able to:

  • list different existing topologies of permanent magnet machines
  • describe and compare distributed and concentrated windings
  • explain the principle of field-weakening for permanent magnet synchronous motors
  • choose the appropriate permanent magnet materials for a given construction with regard to functionality, operating conditions, economical and environmental factors
  • explain and compare the properties of iron laminations and soft magnetic composites in relation to their use in electrical machines
  • enumerate different loss components in a machine and relate them to different existing models
  • develop a simple analytical model of the thermal behaviour of a machine taking into account the relevant losses for the application
  • explain all the tasks in the design procedure and apply them to a surface mounted permanent magnet motor with distributed windings with simplified analytical models
  • explain discrepancies between results from different analytical methods through knowledge about the various approximations they are based on
  • describe the concepts of finite element software tools and apply them in the analysis of permanent magnet synchronous machines
  • report and present the results of the design project that has been conducted for a chosen application
  • do a critical evaluation of the report and presentation of the specific studies conducted by the other students

Course main content

Synchronous electrical machines, permanent magnets, iron lamination, soft magnetic composite, models for losses, thermal modelling, field-weakening, windings, design procedure, finite-element method simulations.


  • Lectures   12 hours      
  • Tutorials  28 hours       
  • Project   36 hours

The main activity in the course is the project.


Completed Bachelor's degree (180 higher education credits), or equivalent academic qualifications. Documented proficiency in English corresponding to English B/English 6.

Recommended prerequisites

basic course in electrical machines and drives EJ2200 or equivalent course at master level (1st year)


Kurs pärm Design of Permanent Magnet Synchronous Machines, KTH, 2008.

Kurslitteraturen består huvudsaklingen av aktuella forskningsartiklar som utdelas vid kursstart.

Dessutom tillkommer relevant kurslitteratur beroende på vald projektuppgift. Föregående läsårs lista av referenser finns tillgänglig på kursens hemsida.

Required equipment



  • PRO1 - Project Report, 3.0, grading scale: P, F
  • PRO2 - Assignments, 1.5, grading scale: P, F
  • TEN1 - Examination, 3.0, grading scale: A, B, C, D, E, FX, F

Oral examination (TEN1; 3 credits), project reports (PRO1; 3 credits), oral presentations with opposition (PRO2; 1.5 credits)

Requirements for final grade

All the different moments have to be passed before the course credits are registered.

Offered by

EECS/Electrical Energy Engineering


Juliette Soulard


Juliette Soulard <soulard@kth.se>

Supplementary information

Course language: English

Limited number of participants. Priority given to students with passed pre-requesites course with highest grade.

This course is intended for students doing their second year of a master program.

Add-on studies

EJ210X Master's Project in Electrical Machines and Drives


Course syllabus valid from: Autumn 2010.
Examination information valid from: Spring 2019.