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EJ2201 Electrical Machines and Drives 6.0 credits

The course deals with the principle of operation and modelling of electrical machines (motors and generators), togheter with the basic control structures used in electric drives. The content of the course is shaped in such a way that students with a background in physics, electromagnetics and electrical circuits should be able to grow their knowledge and understand how different types of electrical machines operate, how to choose an electrical machine and a drive for a specific application, and what are the inherent differences in using a machine with or without a frequency converter. Practical experience in laboratory is part of the course flow.

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Choose semester and course offering to see current information and more about the course, such as course syllabus, study period, and application information.

Headings with content from the Course syllabus EJ2201 (Autumn 2021–) are denoted with an asterisk ( )

Content and learning outcomes

Course contents

  • Electromagnetism and electromechanical models with application to rotating electric machines
  • Principles of electromechanical energy conversion.
  • Dc machines and their electric drive system.
  • Rotating magnetic fields and AC windings.
  • The space vectors and the dq0 reference frame.
  • Operating principles for synchronous machines.
  • Operating principles for asynchronous machines.
  • Introduction to three-phase electric drive systems.

Intended learning outcomes

After passing the course, the student shall be able to
•    describe the basic principles of electromechanical conversion
•    explain the principles of rotating magnetic field generation through the construction of AC windings
•    explain the operating principles of DC machines, synchronous machines and induction machines
•    use analytical models for describing the operation of DC machines, synchronous machines and induction machines
•    use the space vector theory and the reference frame theory to describe the operation of AC machines
•    describe the most important parts of a DC electric drive and a three-phase electric drive.

Course disposition

No information inserted

Literature and preparations

Specific prerequisites

Knowledge in Electric Power Systems, 6 higher education credits, equivalent completed course EJ1200.

Recommended prerequisites

• Electrical circuit analysis (for example EI1110 Electrical circuit analysis, extended course or EI1120 Electrical circuit analysis for the energy and environment program)
• Electromagnetic theory (for example EI1220 Electromagnetic theory E or EI1225 Electromagnetic theory, introductory course for energy and environment)


No information inserted


No information inserted

Examination and completion

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

Grading scale

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


  • LAB2 - Laboratory work, 0.5 credits, grading scale: P, F
  • PROA - Project work, 5.5 credits, grading scale: A, B, C, D, E, FX, 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.

Opportunity to complete the requirements via supplementary examination

No information inserted

Opportunity to raise an approved grade via renewed examination

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

Further information about the course can be found on the Course web at the link below. Information on the Course web will later be moved to this site.

Course web EJ2201

Offered by

Main field of study

Electrical Engineering

Education cycle

Second cycle

Add-on studies

EJ2120 Electric energy conversion, project course

EJ2222 Design of Electrical Machines

EJ2230 Control in Electrical Energy Conversion

EJ2311 Modulation of Power Electronic Converters

EJ2420 Seminars in Electrical Machines and Power Electronics

EJ2440 Electric Transportation

Transitional regulations

The earlier assessing items were LAB1 (0.5 higher education credits, P/F), PRO1 (1.5 higher education credits, P/F) and TEN1 (4.0 higher education credits, A-F). Students who have not completed the course with the earlier examination should follow the new examination rules. However, final mark and course credits are given for TEN1 and PRO1 if a Pass grade is received from the new examination PROA.

Supplementary information

Replaces EJ2200.

In this course, the EECS code of honor applies, see: