Transformer Thermal Curve
Transformer Thermal Curve
(OP)
I have two Transformers whose thermal curves I want to include in a Protection Co-ordination study. The Transformers are approximately 20 year old.
One is 300kVA and the other is 1500kVA.
Both are 3.3kV/415V and oil filled.
Where can I locate typical thermal curves which I can reproduce?
One is 300kVA and the other is 1500kVA.
Both are 3.3kV/415V and oil filled.
Where can I locate typical thermal curves which I can reproduce?






RE: Transformer Thermal Curve
If an overload is set at the transformers rating, no matter the delay you should be fine. (Assuming your relay picks up at the setting and not 150% or so forth)
Short Circuit curves are readily available, but they generally start at 200% of FLA.
RE: Transformer Thermal Curve
The thermal curves for the transformers can be plotted in accordance with ANSI/IEEE standards using the transformer test data if available. This method is preferable since it will give a more accurate damage curve for the transformer. The procedure is contained in standard IEEE Std. C57.109-1993. The following link describes the information contained within http://standards.ieee.org/reading/ieee/std_public/description/dtransformers/C57.109-1993_desc.html
Along with the thermal curves the procedure for plotting the mechanical portion of the transformer damage curves is also contained. Damage curves are plotted based on the transformer category type of which there are four categories for liquid immersed transformers.
The damage cruves can be plotted quite easily by hand once you have the transformer data.
RE: Transformer Thermal Curve
http://www.pes-psrc.org/Reports/K3_TR_Report.zip
RE: Transformer Thermal Curve
RE: Transformer Thermal Curve
http://www.usace.army.mil/publications/armytm/tm5-811-14/chap5.pdf
RE: Transformer Thermal Curve
RE: Transformer Thermal Curve
It was the thermal damage curve that I had meant to refer to.