EJ2400 Electric Traction 6.0 credits

Elektrisk traktion

The course gives an introduction to electric railway traction including traction mechanics, rail systems, electrical drives, and power supplies.

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Offering and execution

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Course information

Content and learning outcomes

Course contents *

Historical survey. General principles of electric traction and traction systems. Tractive and braking effort. Power requirements and energy consumption. Traction vehicles; electric drives, transformers and converters, control and mechanical transmission. Power supply systems; AC and DC supplies, power capacity, overhead catenary systems, overvoltages, line interferences and electromagnetic compability, EMC.

Intended learning outcomes *

After the examination the student should be able to:

  • describe fundamental system issues in electric railway traction including running resistance, tractive effort, adhesion, power and energy consumption.
  • calculate tractive effort, power, acceleration and velocity of rail vehicles
  • describe different components of an electric traction vehicle and their for traction purposes important characteristics
  • make estimations of voltages, currents and power of electrical drives for rail vehicles with induction motors or dc motors.
  • be familiar with other types of electric drives for rail vehicles,
  • describe the design of ac and dc power supplies for electric traction
  • calculate the power capacity for different railway power supply systems
  • Describe the background to electromagnetic interferences (EMI) in electric railway traction and define important concepts and parameters.

Course Disposition

24 h Lecture + 3 Assignments

Literature and preparations

Specific prerequisites *

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

Recommended prerequisites

One of the following courses are recommended; EJ2200 Electrical Machines and Drives, EJ1200 Electric Power Systems or EJ2300 Power Electronics.


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Östlund, S., Elektrisk Traktion KTH 2005

Examination and completion

Grading scale *

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

Examination *

  • INL1 - Assignment, 0.5 credits, Grading scale: P, F
  • INL2 - Assignment, 0.5 credits, Grading scale: P, F
  • INL3 - Assignment, 0.5 credits, Grading scale: P, F
  • TENA - Examination, 4.5 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

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Opportunity to raise an approved grade via renewed examination

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Stefan Östlund

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 EJ2400

Offered by

EECS/Electrical Energy Engineering

Main field of study *

Electrical Engineering

Education cycle *

Second cycle

Add-on studies

No information inserted


Stefan Östlund

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.

Supplementary information

N.B. Courses EJ2400 Electric Traction and EJ2440 Electric Transportation, contain to a certain extent the same material. It is therefore not possible to include both courses for the same degree. A complementary course to EJ2400 Electric Traction can be EJ2410 Hybrid Vehicle Drives.

In this course, the EECS code of honor applies, see: http://www.kth.se/en/eecs/utbildning/hederskodex.