Short Circuit Analysis - X/R ratio given in symmetrical components

Status
Not open for further replies.

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
Prof, Backburn was my teacher and mentor!

Wow, I'm impressed. You must have worked for Westinghouse in the 60s - 70s?

I met him at a seminar in Everett, Wa - mid 70s, maybe 1975. I'd guess he was 60+ at the time.

I was still using a third edition Applied Relaying until about 5 years ago when someone decided they needed it more. (snarl - whine)

ice
 

Phil Corso

Senior Member
Iceworm,

Reur question... No! I was working for Celanese Plastics, at the time! I was also pursuing a MSEE (Power Opt) at Newark College of Engineering! He was Course Instructor, and the grandaddy of Protective Relaying, "Silent Sentinals @ $3.00" was the text!

Phil
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Wow, I'm impressed. You must have worked for Westinghouse in the 60s - 70s?

I met him at a seminar in Everett, Wa - mid 70s, maybe 1975. I'd guess he was 60+ at the time.

I was still using a third edition Applied Relaying until about 5 years ago when someone decided they needed it more. (snarl - whine)

ice

Do happen to have a pdf version of that? I lost mine years ago/ :(
 

Bugman1400

Senior Member
Location
Charlotte, NC
Uhh....are we still talking about sym comp? And, I assume you guys are referring to Lewis Blackburn.

For me, the power industry application of A+jB (sometimes written as A+Bj or A+iB or A+Bi) makes more sense as R+jX. The R is the resistance of the wire and the X is the reactance of the wire. The impedance (Z) is typically written as Z=R+jX and refers to something that has both a resistive (R) and reactive (X) component.
 

Phil Corso

Senior Member
Gentlepeople,

Anyone interested in the how a supply voltage imbalance affects an operating motor's temperature. Specifically, how that temp-rise can be determined using Symmetrical Components?

Phil Corso
 

rcwilson

Senior Member
Location
Redmond, WA
Symmetrical Components Example

Symmetrical Components Example

For a great visual example of Symmetrical components, search for Alex McAherns Power Quality Teaching Toy (https://www.powerstandards.com/PQTeachingToyIndex.php) and download the simulation.

It shows how the positive, negative and zero sequence vectors add to form the unbalanced vectors.

(BTW, Phil, my copy of Blackburn's "Symmetrical Components" is autographed by "J Lewis Blackburn - Oct 1993". That autograph helped me once or twice in relaying discussions with utility engineers).
 

vicdog

Member
Gentlepeople,

Anyone interested in the how a supply voltage imbalance affects an operating motor's temperature. Specifically, how that temp-rise can be determined using Symmetrical Components?

Phil Corso

I would. I have a motor that keeps overheating yet never runs above nameplate.
 

Phil Corso

Senior Member
Vicdog,

If you provide the motor's three phase-to-phase voltages, and the three line-currents, I can demonstrate the process for determining the degree of imbalance! Also include nameplate data, and if known, its operating Power-Factor!

Regards, Phil Corso
 
Status
Not open for further replies.
Top