WTG fault contribution calculations
WTG fault contribution calculations
(OP)
Hi,
Please would anyone be so kind to provide some help on the following.
I have a wind turbine generator connected in series with a wind turbine transformer.
I want to calculate the fault contribution in MVA at 33kV terminals of the 33/0.66kV transformer.
I have a WT generator with fault contribution of 9.55kA at 660V. Its a 2.5MW generator. Rated at 2.525MVA.
The generator transformer is 33/0.66kV, rated at 3.15MVA. R = 0.3175 pu on 100MVA base, X is 2.539 pu on 100MVA base.
Thanks
Please would anyone be so kind to provide some help on the following.
I have a wind turbine generator connected in series with a wind turbine transformer.
I want to calculate the fault contribution in MVA at 33kV terminals of the 33/0.66kV transformer.
I have a WT generator with fault contribution of 9.55kA at 660V. Its a 2.5MW generator. Rated at 2.525MVA.
The generator transformer is 33/0.66kV, rated at 3.15MVA. R = 0.3175 pu on 100MVA base, X is 2.539 pu on 100MVA base.
Thanks






RE: WTG fault contribution calculations
following factors:
a) Equipment Characteristics, configuration and number of WTG and transformers interconnected
b) type of the installed WTGs:
b.1) [u]Type 1 & 2 WTGs[/u]: SC current will be determined by the physical characteristics of the induction generator impedances.
b.2) The WTG Type 3 & 4 SC will be mostly characterized by the power AC/DC/AC BTB power converter’s.
See the enclose article for additional details in this subject.
http://www.nrel.gov/docs/fy10osti/47193.pdf
RE: WTG fault contribution calculations
The article is informative. The current IEC-60909 standards are not giving any special treatment to the WTG short circuit current contribution. I feel, the field of Wind Turbine Generation (WTG) is still emerging, you should consider the worst case of short circuit contribution scenario (i.e.; based on WTG Type-1) for the equipment design.
RE: WTG fault contribution calculations
Since it's a bit of a finger in the air,for the HV side of the transformer I would assume 6x for peak and between 3-4x for the initial symmetrical short circuit current and down to 1.5-1x for RMS break at 90-100ms. This could be a conservative approach if you use the fault current contribution for switchgear assessment, but if you want worst case for protection calculation for fault further in the network I would consider the retained voltage would be reasonable and the converter controls the fault contribution to 1.5x to protect its electronics.
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