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FEJ3221 Design of Permanent Magnet Synchronous Machines 9.0 credits

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.

Course offering missing for current semester as well as for previous and coming semesters
Headings with content from the Course syllabus FEJ3221 (Spring 2012–) are denoted with an asterisk ( )

Content and learning outcomes

Course contents

Function and components of electric drive systems, application specifications, energy conversion in PM machines, torque derivation, loss, thermal constraints, modelling, permanent magnet materials, magnetic materials, topologies of PM machines (radial, axial and transverse), distributed and concentrated windings, field-weakening.

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, economic 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 disposition

12 hours lecture, 2 hours tutorial, 82 (42+40) hours project, 15 hours project meetings

Literature and preparations

Specific prerequisites

No information inserted

Recommended prerequisites

basic course in electrical machines and drives EJ2200


No information inserted


Course folder EJ2221 Design of Permanent Magnet Synchronous Machines, 2011.

Examination and completion

If the course is discontinued, students may request to be examined during the following two academic years.

Grading scale

P, F


    Based on recommendation from KTH’s coordinator for disabilities, the examiner will decide how to adapt an examination for students with documented disability.

    The examiner may apply another examination format when re-examining individual students.

    At least 1 full-time week of project activity is preferably linked to the student’s own research.

    Other requirements for final grade

    • 6 status reports
    • 5 oral presentations
    • 5 opposition reports
    • Final report and oral examination

    Opportunity to complete the requirements via supplementary examination

    No information inserted

    Opportunity to raise an approved grade via renewed examination

    No information inserted


    No information inserted

    Ethical approach

    • All members of a group are responsible for the group's work.
    • In any assessment, every student shall honestly disclose any help received and sources used.
    • In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.

    Further information

    Course web

    No information inserted

    Offered by

    EECS/Electric Power and Energy Systems

    Main field of study

    No information inserted

    Education cycle

    Third cycle

    Add-on studies

    No information inserted

    Postgraduate course

    Postgraduate courses at EECS/Electric Power and Energy Systems