High-altitude Transmission Substation specs

[kokotiko]

Where can I find specs and special requirements for designing an air-insulated transmission (say 50MVA) power substation situated at an altitude of 1000m (or more) above sea-level?

 

[cuky2000]

The altitude primarily affect the dielectric ratings of the system and electric components BIL & BSL and in less degree the power frequency ratings.

Beware that electrical components not exposure to air (i.e. oil transformer winding & SF6/vacuum bkr interrupters) do not require dielectric rating. However, thermal derating (Amp or MVA) may be required at high altitude.

On the other hand, dielectric rating for some equipment such as surge arrester could go much higher than 1000 m without derating. Bushings and insulators exposed to air should be derated way under 1000 m.

Check the following sources:IEEE Std C37.30, IEEE Std C37.40, IEEE Std C37.100, NESC (for safety clearances), IEC Std 60071-2, etc.

http://www.eng-tips.com/viewthread.cfm?qid=24254

http://downloads.eatoncanada.ca/dow...ontrol - High Altitude - Application Note.pdf

 

[odlanor]

kokotiko
It is not produtive and reliably to make specs and special requirements for designing an air-insulated transmission power substation situated at an altitude above of 1000m.
We had a problem like that , to project a 230kV substation to be installed at Andes( Equador). Manufactures offers equipment standards of 345kV with a very wide 345kV air-insulated switchyard.
Soon, we discover that client utility only used 230kV SF6-substation at Andes.

 

[cuky2000]

Odlanor,

We worked in several projects at high altitude in many part of the wold including Colorado and Arizona in the US and also in Peru, Chile in SA and provided consulting services as far as China and other countries around the world >4000 m (>12,000 ft) above MSL obtaining similar or higher degree of reliability than comparable HV installation under 1000 m without drastically penalizing the cost of the facility.

If the external insulation is not derated, the installation is at risk of catastrophic failure do to reduced dielectric strength.

In many develop countries, power outage are common. This often confuse the issue of delivering substandard installation at apparent "reduced cost" in violation to world wide proven good engineering practices.

I suggest that you should review your concept on reliability and application for substations at high altitude.