We have a number of recognized transmission and distribution experts serving on our board of "Grid Masters." Several times each month we’ll post what we judge to be the toughest questions that also have high interest to our readers. At least one of our experts will respond. Want to challenge our Grid Masters for a chance to win?

Q: I am an electrical engineer, graduating years ago. I forgot how to determine the symmetrical components and unbalanced fault using a five bus system with motors and generators on the five different buses. Could you please explain how to calculate the unbalanced fault for the five bus system?
John Grzesiak (USA)

A: John, I'm afraid this excellent question is a bit too complex to answer in the space that we have. However, several experts recommended references that can bring you up to speed. See below.

Paul Mauldin
Editor- Grid Optimization

Here's an excellent text book – Power System Analysis & Design by J. Duncan Glover and Mulukutla Sarma. I used this all through graduate school and it has excellent examples on how to use symmetrical components. I am still using it in my consulting work when I need a reminder.

Gene Wolf, PE
Lone Wolf Engineering, LLC

In addition to the text suggested by Gene, there is a text by Edith Clarke of GE - Circuit Analysis of A-C Power Systems, which is an excellent reference on Symmetrical Components.

Michael Bahrman
HVDC Business Development
ABB

The text by Edith Clarke is considered a bible. She was the first female professor of EE at University of Texas.

Dr. Mietek Glinkowski, P.E
Global Head of Technology
ABB