Transmission at Medium Voltage 4160V

[burnt2x]

Hi,
I have a proposal to upgrade a distribution line 4 km long that is now loaded up. The load has increased from the design load of 600 kVA to around 1.3 MW (almost 2X) so that they opted to install gensets to the newer buildings.
Other than going into a higher transmission voltage (13.8), is there any other economical ways to meet a load of around 1.3 MW (do away with the gensets)?
Any comment would be helpful.

Respectfully,

burnt2x

 

[itsmoked]

What could cost less than 13.8?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[davidbeach]

A lot more detail is necessary. Like what voltage are you at now? Distribution line suggests something higher than 480V, but 600kVA suggests something even possibly lower.

 

[burnt2x]

David,
Thanks for the response.
Transmission voltage is currently at 4160V. Existing OH line is #4 ACSR, spaced 0.6 m horizontal. I have done initial investigations and the receving voltage at the 4 km end is at 3740V corresponding to a load of 76A/line. Any more load and the voltage goes down further. I was thinking upgrading to 13.8 kV. Just want to know if somebody has done similar upgrades.

 

[waross]

4 km of insulators and a lot of labor to change them does increase the cost.
But this is probably still a good idea.
4160 is usually a wye system with 2400V transformers.
If you are using 4160 transformers in delta, you can increase the power by a factor of 1.73 by going to a wye connection, but I doubt that you are in delta.
As I understand it, the origin of the 4160 voltage was the reconnection of 2400 volt delta systems to increase capacity.
From experience, if you go to 12.7kV, 13.2kV, 13.8kV or any of the other voltages that you may find in the 15kV class, buy 7 transformers. You may have trouble finding an exact voltage match if you lose a transformer and need a replacement in a hurry. Have a replacement on hand and you will have time to shop for a reasonably priced replacement at the correct voltage if you lose a transformer.
Again, after consulting for a small independent utility that ran 13.2kV in a country that used 13.8kV on the main grid, I would first check what voltages are in use by surrounding utilities and I would check with the local distributors as to what voltage transformers are in stock.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[burnt2x]

waross, good points. I will keep those in mind.
And thanks a lot!

 

[davidbeach]

A voltage regulator and/or capacitors might also be enough to hold the voltage up enough to support more load. Missed the 4160V in the title, just read the post.

 

[dpc]

You can re-conductor at the same voltage if it makes economic sense and the serving transformer has adequate capacity. This would depend on expectation of future growth, condition of system, availability of capital, etc.



"An 'expert' is someone who has made every possible mistake in a very narrow field of study." -- Edward Teller