Symmetrical Components and sequence circuits

[Engineer1916]

Hello Everybody,
I have a pretty goo understanding of the symmetrical components(atleast the mathematical part). What confuses me is the symmetrical component circuits of different pieces of equipment. Like oh we have a wye-delta transformer, here is the zero sequence, positive and negative sequence circuit will look like.
Any good reference with explanation to the circuit part will be highly appreciated.

Thank you.

 

[davidbeach]

See faq238-1287. In particular the Blackburn Symmetrical Components and Anderson Analysis of Faulted Power Systems books will be of great value. Should be on everybody here's library shelf.

 

[WHiPCPL]

Electrical Transmission and Distribution reference book has all the two-circuit transformer, two-circuit autotransformer, three-circuit transformer and three-circuit autotransformer; positive and zero sequence equivalent circuit. There's also derivation of some of them, but not all.

Be warned it's an expensive book if you want the 1964 edition (haven't found the 2008 edition on Amazon although it might be on Ebay). The 1950 edition is currently half the price of the 1964 edition, although I can't say for sure how different they are aside from the 1964 edition having three extra chapters and the 2008 edition has one extra chapter compared to the 1964 edition. Although aside from that ABB didn't update the information in when they remade the 1964 edition with a 2008 edition as far as I know.

 

[Engineer1916]

Thank you people for the help.
I checked these books out. Blackburn Symmetrical component is a very good book.

ps: YOu can find these books on scribd, if you have the scribd membership.

 

[prc]

1)Zero sequence impedance of transformers with different connections is given in IEC 60076-8 Application Guide.

2)Westinghouse Electric Corporation, Central Engineering Group published the classic "The Electrical Transmission and Distribution Reference Book" way back in 1942.Several editions came out and the last was ed5.0 under ABB in 1997.Unfortunately this classic prepared with so much hard work was never revised, probably as no one was prepared to spare the hard work required. Now, within couple of months, ABB power division will be taken over by Hitachi and let us see what will happen.

3) A little personal story- I first saw this book,more than 55 years back when I was in college studying Electrical Engineering in India. One of my class mates brought this volume to class. He got it from his father who was a senior engineer at local electric utility. He had been to Canada for training at some factory and purchased the volume from there. We were really impressed by the quality of the book ( A4 size weighing more than half Kg)and I decided to have this once I started earning. Soon after joining a transformer factory, I could purchase this volume as US government was giving subsidy for printing Indian edition of such classics from the export of wheat to India under PL-480 law of senate. We were paying for wheat in Indian rupees as we had no foreign exchange.(today Indian population doubled, but our wheat production increased so much that we are exporting grain-that is the greatness of scientific revolution) I got the volume for Rs20(less than USD 3 at the then exchange rate) but great sum for me then as it costed almost 8 % of my monthly earnings!

 

[Engineer1916]

prc,
than you for the IEC reference. I will check it out. Right now I am going through blackburn book recommended in the top. It is answering my questions so far.
Thank you for sharing your story. It is fascinating how it takes few clicks now to get the same book within minutes.

And also thank you very much for being an active member and answering the questions of young engineers like myself. I have seen your responses on couple of my threads.

 

[cuky2000]

Transformers and transmission lines usually Z[sub]1[/sub]=Z[sub]2[/sub]≠Z[sub]0[/sub]. The zero sequence impedance for a 3-phase transformer is obtained exiting the unit with a single-phase source and measuring the current such as Z[sub]0[/sub]=V/I[sub]1Φ[/sub].
Rotating machines Z[sub]1[/sub]≠Z[sub]2[/sub]≠Z[sub]0[/sub]
For illustration, here is an animation of the sequent components in wave and vector form Link