Fundamentals of Three-Phase Electrical Transformers

This course covers electromagnetism, voltage and current transformation, ratios & polarity, potential & current transformers, 3-phase transformer construction, transformer classifications, losses & cooling, per unit, etc. 9 lessons in 5h 37min total course length.

Course Description

This course will teach you the fundamentals of electrical transformers in terms of electromagnetism, voltage and current transformation, ratios, and polarity, potential and current transformers, 3-phase transformer construction, transformer classifications, losses, and cooling, per unit, etc.

Electromagnetic forces interact with electrically charged particles and electromagnetic fields; this course will study how these forces lead to voltage and current transformation. Ratios and polarity are also studied leading to the introduction of potential transformers & current transformers, and their use in conjunction with the relevant instruments such as ammeters, voltmeters, wattmeters, and energy meters.

We will cover transformer core construction along with losses and cooling mitigation techniques. 3-phase transformer configurations are studied along with harmonic distortion, CT saturation, and on-load tap-changer problems and how these problems are dealt with.

Overcurrent and restraint differential transformer protection is explained in detail, along with a look at some examples of “Old School relays” as well as modern IEDs (intelligent Electrical Devices).

Transformer Connections: (Y–Y; Delta-Delta; Y-Delta; Delta-Y and Y-Zag Zig) are examined along with Transformer Clock System Vector Nomenclature. Oil Analysis and the Buchholz Relay are also studied.

Course Summary

  1. Introduction
  2. The Ideal Transformer
  3. The Real Transformer
  4. Instrument Transformers
  5. Three-Phase Power Transformers
  6. Transformer Clock System Vector Nomenclature
  7. Transformer Construction and Cooling
  8. Transformer Protection
  9. Transformer Relays
  10. The Final Exam With 24 Questions

Who Is This Course For

  • Electrical Engineers
  • Technologists
  • Technicians
  • Electricians
  • Managers and Supervisors
  • Superintendents
  • Electrical Engineering Students


Basic Electrical Mathematics, Trigonometry

Downloadable course materials

After purchasing the course, students can download the following guides and papers:

  • Transformers and equipment in underground distribution systems (PDF)
  • The basics of power transformers in transmission and distribution grids (PDF)
  • Current and Voltage Instrument Transformers – Technical and Application Guide (PDF)
  • Construction and Maintenance of High Voltage Power Transformers For Students (PDF)
  • Distribution transformers analysis and maintenance practices (PDF)
  • Protection Of MV/LV Substation Transformers (PDF)
  • Protection of HV Transformers (PDF)

About Instructor

Graham Van Brunt P. Eng., B.Sc.

An entire career in the power sector of engineering, Graham graduated from Queen's university coupled with subsequent studies with Wilfrid Laurier University to travel the globe and apply his skills and garner his protection and control experience internationally. His passion for staying in touch with his profession and his kinship for mentoring has kept him in front of an audience of learners.

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Course Includes

  • 9 Lessons
  • 9 Topics
  • 1 Quiz
  • Course Certificate
  • Lifetime Access