Print this page Print this page

Switching Transients Analysis Fundamentals

Velimir Lackovic, MScEE


Course Outline

Switching transients severe enough to cause problems in industrial power systems are most often associated with inadequate or malfunctioning breakers or switches and the switching of capacitor banks and other frequently switched loads. The arc furnace system is most frequently studied because of its high frequency of switching and the related use of capacitor banks.

By properly using digital computer programs these problems can be detected early in the design stage. In addition to these types of switching transient problems, digital computer programs can be used to analyse other system anomalies such as lightning arrester operation.

This course begins with a discussion of the switching transient phenomena, describes root causes and explains system operation is affected. A detailed explanation of modelling and calculation procedure is offered. Selection and sizing of surge arrester is covered in details. Explained techniques can be implemented in any commercial power system software package.

This course includes a multiple choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will:

Intended Audience

This course is intended for electrical engineers.

Benefit to Attendees

Attendees of this course understand basic theory behind switching transient analysis and how switching transients affect power system operation. Also attendee will understand consequences of excessive switching transient levels and what mitigation measures can be applied.

Course Introduction

An electrical transient occurs on a power system each time an abrupt circuit change occurs. This circuit change is usually the result of a normal switching operation, such as breaker opening or closing or simply turning a light switch on or off. Bus transfer switching opera­tions along with abnormal conditions, such as inception and clearing of system faults, also cause transients.

Most power system transients are oscillatory in nature and are characterized by their transient period of oscillation. Despite the fact that these transient periods are usually very short when compared with the power frequency of 50 Hz or 60 Hz, they are extremely important because at such times, the circuit components and electrical equipment are subjected to the greatest stresses resulting from abnormal transient voltages and currents. While over-voltages may result in flashovers or insulation breakdown, overcurrent may damage power equipment due to electromagnetic forces and excessive heat generation.

Course Content

In this lesson, you are required to download and study the following course content in PDF format:

Switching Transients Analysis Fundamentals

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

Course Summary

Clear understanding of the electrical circuits during transient periods is essential in the formulation of steps required to minimize and prevent the damaging effects of switching transients. This course introduces basic terms, equations and calculation methodologies that are used to assess electrical transients in the power systems.

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

Take a Quiz

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.