11 KV Transfomer

If you increase primary turns, you increase the overall transformer ratio and decrease secondary voltage.

Given your example, 11kV to 400V is 55:2, or if you use 100 then 100:3.64 (Don't blast me - this is just an example). If you increase the turns to 108 and your primary voltage remains the same, then your secondary voltage becomes approx. 367V.

There is a basic explanation of transformer theory at http://64.78.42.182/sweethaven/ModElec/acee/lessonMain.asp?iNum=0502

So your transformer ratio is 11kV/400V. the turns of the primary is proportional to the transformer voltage ratio and inversely proportional to the current ratio. 100 primary turns will give you 40000/11k secondary turns. that,s 3.64 or 4 turns on the secondary. Increasing the primary turns decreases the secondary voltage. If you change tap to 108 turns to the primary, since 4 (3.64) turns was established in the secondary, your transformer ratio may be expressed as 108/4. With a primary voltage of 11kv the new secondary voltage is 11kV x (4/108) = 370.74.

I have a question in return, are you asking this question just to increase your knowledge & understanding of the subject, or will you be actively working/adjusting on a transformer after reading all of the replies?

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