3T-Basic Fundamentals of AC Circuit Analysis

Overview

Credit: 2 technical hours

The method of symmetrical components is used to simplify asymmetrical three-phase voltages and current by converting the unbalanced system into two sets of balanced phasors and a set of single-phase phasors, or symmetrical components. These sets of phasors are called the positive, negative, and zero sequence components. An understanding of this method is essential for the understanding of fault analysis and modern-day protection schemes. This course will provide you with the knowledge to comprehend the concept and how it is applied.

In this course, you will learn what symmetrical components are, their main advantages, and how manufacturers of equipment use them. You will learn how to use symmetrical components to simplify asymmetrical three-phase voltages and current and understand fault analysis. In the case of three-phase systems, the resulting “symmetrical” components are referred to as direct (or positive), inverse (or negative), and zero (or homopolar). The analysis of power systems is much simpler in the domain of symmetrical components because the resulting equations are mutually linearly independent if the circuit itself is balanced.

You can later apply this knowledge to single-phase to ground, two-phase to ground, phase-to-phase, and three-phase fault conditions. This course may be considered a prerequisite to the course “Short Circuit Analysis for High-Voltage Three-Phase Systems.”

Specific Knowledge or Skill Obtained

This course teaches the following specific knowledge and skills:

• Discern the make-up of each of the components
• Simplify Asymmetrical 3-phase quantities using the Synthesis Equations
• Analyze Asymmetrical 3-phase problems using Symmetrical Components
• How to utilize the “a” operator
• The utilization of Symmetrical Components