Transformer Testing using IEEE C57.90 1

[freefallingbody]

Hi,

A simplified method of conducting short circuit testing of 3 phase transformer is given in the above standard, by using a single phase source. On the H.V. side ( delta) apply small voltage between lines ( HR-HY) and keep all the L.V. side LR, LY & LB( Star) terminals short circuited.

I wonder if shorting all three L.V. terminals would cause flux linkages in the third phase as well. In other words, is it not sufficient to short only LR and LY when I connected a single phase source across HR and HY? Whether my wattmeter readings would be diffreent if I short LR, LY and LB?

Comments please..

 

[busbar]

If the citation is IEEE C57.12.90, another reference may be C57.123 IEEE Guide for Transformer Loss Measurement.

 

[ScottyUK]

Yes, you will get flux linkages and current will circulate in the other phases. I think you will see a 2/3 - 1/3 current distribution on the LV side, with the 2/3 of S/C current in the phase corresponding to the one whose primary you are energising.




-----------------------------------

Start each new day with a smile.

Get it over with.