Frequent energizing of transfromer in solar field
Frequent energizing of transfromer in solar field
(OP)
Hello,
I am working for a solar company, they plan on creating a 900mw solar field. There has been talk about turning off all the power distribution equipment at night to save money. (No-load current, magnetic flux, hysteresis and eddy current losses)
What are your thoughts on 30 years of de-energizing and re-energizing transfromers every morning and night? (11,000 times)
I am under the impression that this may reduce the life of the transfromer. Anyone have an data that shows this?
Thanks for your help.
Cameron
I am working for a solar company, they plan on creating a 900mw solar field. There has been talk about turning off all the power distribution equipment at night to save money. (No-load current, magnetic flux, hysteresis and eddy current losses)
What are your thoughts on 30 years of de-energizing and re-energizing transfromers every morning and night? (11,000 times)
I am under the impression that this may reduce the life of the transfromer. Anyone have an data that shows this?
Thanks for your help.
Cameron






RE: Frequent energizing of transfromer in solar field
RE: Frequent energizing of transfromer in solar field
You could always use synchronous starting and stopping to leave the magnetics in a known state and start them at the correct time. I suspect that would remove the cycling issue.
Bring up the transformer from the LV side.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Frequent energizing of transfromer in solar field
The site will have 1000-1500 total transfromers. Starting with hundreds of small ones going from 575vAC-5kvAC, all the way up to the large 500kvAC output units that take it to the grid.
I agree with your statment of "more reliable life", but what does that really mean? Will we have many failures over the 30 year life? A few? One?
How could I quantify the reduction in reliability of frequent cycling of the transfromers?
RE: Frequent energizing of transfromer in solar field
Thats an interesting idea, it would reduce the mechanical stresses, however like david said the thermal loading from operation at day/off at night would still be quite a problem.
I am not sure I could bring them up from the LV side, we need the grid to start the system every morning, we have lots of inductive loads(motors) to start in the morning as the system tracks the sun.
RE: Frequent energizing of transfromer in solar field
How about a different approach—specifying transformers with very limited no-load losses? It may likely save on switchgear wear and tear in the process.
RE: Frequent energizing of transfromer in solar field
However there is a limit on size of dry type transformers.
RE: Frequent energizing of transfromer in solar field
Oil filled transformers are designed to breathe and so have desiccant in breather lines. Switchgear can be provided with space heaters. Cables and terminations are out there on their own.
Another consideration with transformers, of all types, is the physical expansion and contraction associated with the thermal cycling. Your cores will wear and become loose over time where that is not generally a consideration.
RE: Frequent energizing of transfromer in solar field
You are right that the thermal cycling would loosen most of the transformer parts over time. However this should be part of the duty spec of the transformer, and would surely increase the cost of same.
If switchgear is used keeping the heaters on would reduce some of the issues with breakers, and cable terminations.
RE: Frequent energizing of transfromer in solar field
RE: Frequent energizing of transfromer in solar field
RE: Frequent energizing of transfromer in solar field
RE: Frequent energizing of transfromer in solar field
Area is Southern CA desert. Barstow. Very hot and dry most of the time, untill the monsoon season.
Does anyone know of any documents or regulations talking specificly about frequent energizing of transformers and expected life?
Thanks everyone.
RE: Frequent energizing of transfromer in solar field
RE: Frequent energizing of transfromer in solar field
Keith Cress
kcress - http://www.flaminsystems.com