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Symmetrical Components in Three-Phase Systems

This free online course will teach you about 3-phase networks and the analysis of short-circuit fault conditions.

Publisher: Graham Van Brunt
This free online course will introduce you to the concept of symmetrical components developed by Charles Fortescue. You will learn about the three-phase networks and the analysis of short-circuit fault conditions with the help of symmetrical components. Also, by studying this free course, you will discover exactly what symmetrical components are, their major benefits and how manufacturers of equipment utilise them in the power industry.
Symmetrical Components in Three-Phase Systems
  • Duration

    1.5-3 Hours
  • Students

  • Accreditation






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This course will provide you with a basic understanding of symmetrical components. The analysis of a steady-state three-phase electrical system using a per-phase equivalent circuit is relatively simple.  But, this method is only valid when the voltages and currents are balanced with each phase having the same impedance. The analysis becomes much difficult when the phase voltages and currents are unbalanced during faults and short circuits. In such conditions, the symmetrical components are used for the analysis of asymmetrical currents and voltages. It is a powerful mathematical technique used in power system protection as It helps to analyse the power system faults. In this course, you will be taught how to represent a set of unbalanced phasors into three independent sets of balanced phasors or symmetrical components and analyse the fault conditions. But first, you will be getting an overview of what the symmetrical components are, who developed them and how the phasors are described in terms of symmetrical components.

Next in the course, you will be introduced to the basics of the symmetrical components as described by Fortescue and learn the standard notation used to represent the components. You will learn about the properties of the positive, negative and zero sequence components of the electrical system and their mathematical interpretations. Thereafter, you will learn to resolve an unbalanced network of three related vectors into three sets of independent vectors. As there are three sets of symmetrical components and also three phases, you will learn about the 3X3 = 9 different ways of representing the unbalanced fault condition. Upon that, you will be shown how equations are developed with symmetrical components and used in the analysis of different unbalanced faults. You will also be apprised of the properties of the ‘a’ operator that is used to re-describe the phasors of the various components in terms of the ‘a’ phase that further simplifies the analysis. The course will also help you understand how symmetrical components are used to analyze electric systems through problems and their solutions worked out.

In today’s power industry, complex system problems are analyzed using computer algorithms. This course will help you understand how the symmetrical components are applied to solve such problems in the power system. Anyone with a knack for learning new skills can take this course. However, a basic understanding of the laws and theorems related to 3-phase electrical power systems and basic maths is essential. This course will be most beneficial to electrical engineers, technologists, substation engineers, maintenance workers in the electrical power protection industry and others who want to understand how electric power systems are modeled. An understanding of the use of the symmetrical components technique will also enable you to work on all the fundamentals of power system protection and control. This course will also help you in studying power protection systems for a career in power engineering and electrical engineering. So why wait? Enrol now and study for free!

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