How to Calculate Number of Feeder for Substation?

TO

If you want to know how to calculate the no. of feeders in your question .... i would suggest first that know your connected loads first... it logical my friend ... make some assumptions to your system and you know how to put-up a no. of feeders in your system.

dear ,

not only the electrical load details, but the concentric load pockets - geographically distributed, also to be considered....!

In general, I may derive a formula from your question....

No. of out going feeders = no. of concentric load pockets + future spares+space for 2 feeders if required for un known reasons.

Is this a theoretical exercise, school assignment or general interest? I hope you are not working for a power or consultancy company and actually trying to create a design for an actual substation by yourself when you don't know how to size busbars and feeders.

Can you please provide more information on why you are asking these basic questions, I am not comfortable about the legal and ethical ramifications of providing even basic advise that may result in the loss of life and/or destruction of property.

Jack - A Substation Engineer (among other things)

Dear sir ,

I am a final year student.My ambition will go to substation Design .So i would like to know this all basic thing.I hope you are worked as substaion Engineer.

so you have lot exposure on the substaion..can you provide some information regarding substaion design...

In your College Library ask for a book titled "Electrical Sub-station Design" by Mr. M.V. Deshpande and study the same.

Thank you for clarifying this point, many similar questions are asked on CR4 and not all of them are from students interested in general knowledge.

There are plenty of good resources available on the internet for free. I would recommend the following ebooks and websites which cover the topics you are interested in (to varying degrees).

http://www.energy.siemens.com/us/en/energy-topics/publications/power-engineering-guide/

http://www.schneider-electric.com/sites/corporate/en/products-services/technical-publications/technical-publications.page

http://www.idc-online.com/

http://ecmweb.com/

Additionally an internet search will give you plenty more.

For determining number of feeders from 33/11 KV substation you have to do the followoing exercise.

1- Determine the number of load centers according to the geografical existance and the catagory of the loads to be fed.

2-Determine if you want your feeders to form a ring with the same substation, ofcourse with the different bus section.

3- Determine the size of the each feeder and that again interdepends on the size of the building i.e how many 11 kv panels it can accommodate, because each 11 kv cubical will require approximately 1 meter space. If you have space consstraint you have to have less number of feeders with higher rating.

there are other factors which are to be taken in account, but most vital are the above factors who should decide the number of feeders.

Say if you have 2 nos. incoming source, 2 nos 11/415V distribution transformer, 4 nos. other 11kV loads and 2 nos. spare for future

The no. of outgoing feeders will be 8, 2 incomers and a bus-sectionaliser.

Total no. of 11kV switchgear panels will be 11.