Transformer impedance IEC estandard
Transformer impedance IEC estandard
(OP)
Hello, I need the impadance of a transformer of 630kVA, 11kV/400V on IEC Standar.
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
Download nowINTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Transformer impedance IEC estandard
|
Transformer impedance IEC estandardTransformer impedance IEC estandard(OP)
Hello, I need the impadance of a transformer of 630kVA, 11kV/400V on IEC Standar.
Red Flag SubmittedThank you for helping keep Eng-Tips Forums free from inappropriate posts. Reply To This ThreadPosting in the Eng-Tips forums is a member-only feature.Click Here to join Eng-Tips and talk with other members! |
ResourcesWhat is rapid injection molding? For engineers working with tight product design timelines, rapid injection molding can be a critical tool for prototyping and testing functional models. Download Now
The world has changed considerably since the 1980s, when CAD first started displacing drafting tables. Download Now
Prototyping has always been a critical part of product development. Download Now
As the cloud is increasingly adopted for product development, questions remain as to just how cloud software tools compare to on-premise solutions. Download Now
|
RE: Transformer impedance IEC estandard
David Castor
www.cvoes.com
RE: Transformer impedance IEC estandard
RE: Transformer impedance IEC estandard
For rated power from 25 to 630kVA, Minimum short-circuit impedance : 4%
RE: Transformer impedance IEC estandard
replace : IEC 60076-5 (Recognized minimum values of short-circuit impedance for transformers with two separate windings)
By : IEC 60076-5 (Power transformers – Part 5: Ability to withstand short circuit / Table 1 : Recognized minimum values of short-circuit impedance for transformers with two separate windings)
RE: Transformer impedance IEC estandard
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Transformer impedance IEC estandard
RE: Transformer impedance IEC estandard
60076-5 gives recognized minimal values (not mandated),and states :
'Commonly recognized minimum values for the short-circuit impedance of transformers at the rated current (principal tapping) are given in Table 1. If lower values are required, the ability of the transformer to withstand short circuit shall be subject to agreement between the manufacturer and the purchaser.'
RE: Transformer impedance IEC estandard
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Transformer impedance IEC estandard
Usually for 630 KVA uk%=4 but I encountered uk%=6 for short-circuit limitation reason. The accuracy is about [ +/-] 7-10% and is stated by manufacturer. Also X/R ratio is about 5 but this
depends upon copper losses[short-circuit losses].
If you intend to order a transformer "tailor made" you may require a suitable uk%. If the uk% is too small the short-circuit current will be high and the limit will be the breaker rating, I suppose. If the uk% will be high the voltage drop across the transformer could be a problem.
See a specification model, for instance:
http://w
RE: Transformer impedance IEC estandard
To know generally specified impedance values for transformers around the world, refer to IEC TR60909-2 ed2.0(2008-11) Data for electrical equipment for short circuit current calculations.
At the end of 19th centuary when transformer engineering was taking shape,impedance values for transformers were extremely low. As SC level went up and transformers started failing, users started asking for a minimum impedance value of 4 % .