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System Failure – Anatomy of a Blackout

Part II – Cascading Failure of the Power System

Lee Layton, P.E.


Course Outline

The course begins with an overview of how the Eastern Interconnect is structure in the northeastern part of the United States.  How the cascade affected such a wide area is discussed and how the cascade evolved into a high speed event that was virtually impossible to control is reviewed.  Then we look at how the system finally found equilibrium and the system returned to stability leaving 50 million people in the dark.

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

Learning Objective

After taking this course you should:

Intended Audience

This course is generally written at a non-technical level and is suitable for anyone interested in how a complex electrical system failure due to human error.

Benefit to Attendees

The lessons learned from this failure are beneficial to any technical field.  The human and technologies of the August 14, 2003 blackout are similar to failures in many industries, from structural engineering to the space program.

Course Introduction

On August 14, 2003, just after 4 p.m. Eastern Daylight Time (EDT), the North American power grid experienced its largest blackout ever. The blackout affected an estimated 50 million people and more than 70,000 megawatts (MW) of electrical load in parts of Ohio, Michigan, New York, Pennsylvania, New Jersey, Connecticut, Massachusetts, Vermont, and the Canadian provinces of Ontario and Québec.

Although power was successfully restored to most customers within hours, some areas in the United States did not have power for two days and parts of Ontario experienced rotating blackouts for up to two weeks.

This course looks at the conditions on the bulk electric system that existed prior to and during the blackout, and explains how the blackout occurred. Note that since this report was originally written, several of the companies and organizations mentioned in the report have merged or r organized.

Immediately following the blackout, NERC assembled a team of technical experts from across the United States and Canada to investigate exactly what happened, why it happened, and what could be done to minimize the chance of future outages. The scope of NERC’s investigation was to determine the causes of the blackout, how to reduce the likelihood of future cascading blackouts, and how to minimize the impacts of any that do occur. NERC focused its analysis on factual and technical issues including power system operations, planning, design, protection and control, and maintenance.

This course is Part II of a two part series about the August 14, 2003 blackout.  Part I covered the events leading up to the black and gave an overview of the conditions prior to the start of the system failure and described the conditions for the hours preceding the cascading failure of a large part of the Eastern Interconnect.  Part II covers the actual cascading failure and describes how it spread, and finally stopped.

Course Content

This course content is in the following PDF document:

System Failure – Anatomy of a Blackout: Part II – Cascading Failure of the Power System

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

The August 14 blackout had many similarities with previous large-scale blackouts, including the 1965 Northeast blackout that was the basis for forming NERC in 1968, and the July 1996 outages in the West.

Common factors include: conductor contacts with trees, inability of system operators to visualize events on the system, failure to operate within known safe limits, ineffective operational communications and coordination, inadequate training of operators to recognize and respond to system emergencies, and inadequate reactive power resources.

Quiz

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

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.