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EJ2301 Power Electronics 6.0 credits

Electricity plays a vital role in supplying energy to computers, electronics, industrial processes, trains and many other applications. They all have in common that the electrical energy has to be converted and controlled in a precise manner.
This course provides in depth knowledge of power converter topologies, their characteristics and principles for their control. The course also covers the basics of modern power semiconductors.

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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 EJ2301 (Autumn 2022–) are denoted with an asterisk ( )

Content and learning outcomes

Course contents

Today electricity plays a central role when providing energy to computers, electronics, industrial processes, and trains. They have in common that the electric energy must be converted and controlled accurately. This course provides a deep understanding of the function of power converters, structure and how they are controlled. The course also covers the basics of modern power semiconductor devices

Intended learning outcomes

After passing the course, the student shall be able to

  • describe the function of DC-DC converters, line-commutated converters, switch-mode inverters, and switch-mode power supplies by means of basic equations for inductances and capacitances
  • calculate average values, RMS values, ripple and fundamental components of voltages and currents
  • calculate instantaneous values, average values, active, reactive, and ripple powers of above-mentioned power converters
  • describe different operation modes for above-mentioned power converters and decide whether the converter works in continuous or discontinuous operation mode if applicable
  • schematically describe the control of the power converter
  • describe the function of power semiconductor devices and how they are controlled and be protected
  • describe the function of a DC motor
  • dimension a step-down DC-DC converter both electrically and thermally such that given specifications are fulfilled
  • apply state-space averaging to control a step-down DC-DC converter

in order to

  • learn tools to describe and analyse circuits and control methods for power converters
  • be able to describe and apply power semiconductor devices and their control and protection circuits.

To obtain higher grades, the student shall be able to

  • analyse the function of DC-DC converters, net commuted converter, switch-mode inverters, and switch-mode power supplies to decide limits for discontinuous operation, evaluate multi-quadrant operation and decide values for circuit element such that given specifications for stationary and transient operation are fulfilled
  • analyse complex waveforms for convert quantities by means of Fourier analysis such that harmonics and their impact on the operation can be evaluated
  • analyse transient operation of DC-DC converters, line-commutated converters, switch-mode inverters, switch-mode power supplies, and DC motors by means of linear ordinary differential equations
  • calculate magnetomotive forces, flux densities, magnetic fluxes, inductances and winding turns of magnetic circuits that are exposed to quantities from power converters

Course disposition

Lectures 28 h
Exercises 20 h
Web task 10 h
Seminars 10 h
Laboratory class 2x4 h
Project 15 h

Literature and preparations

Specific prerequisites

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

Recommended prerequisites

EJ1200 Electric Power Systems basic course or equivalent.


No information inserted


Mohan/Undeland/Robbins: Power Electronics: Converters, Applications, and Design, John Wiley & Sons

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


  • LAB1 - Laboratory Class, 0.5 credits, grading scale: P, F
  • PRO1 - Project Work, 1.0 credits, grading scale: P, F
  • SEM1 - Peer Assessment, 0.5 credits, grading scale: P, F
  • TEN1 - Written Exam, 3.5 credits, grading scale: A, B, C, D, E, FX, F
  • XUP1 - Web-based Module, 0.5 credits, 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.

Other requirements for final grade

The final mark is based on the written examination but bonus point can be received from LAB1, PRO1, SEM1, and from the exercises.

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 EJ2301

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

Supplementary information

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