Just a minor point, but the tap changer acts invariably on the HV side winding (and for this voltage transformation, will be off load or off circuit changing).
Apologies - it seems my earlier post was incorrect, OMS deals with more of this HV stuff for his day job, I have met such things but occasionally, so he will be better informed.
Note then the impedance will vary a bit as the tap changes, but even so only at the 5 % of 5% sort of level. (you cannot alter the volts per turn much, or the core losses go out of whack)
(However, 1960 era transformers with manually bolted taps can be found on the LV side, as at the University they were just that. Equally that transformer caught fire in 1995 apparently, so maybe that is an obsolete way of doing it or it was a special design for that installation - perhaps physics depts just have some funny requirements)
Just a minor point, but the tap changer acts invariably on the HV side winding (and for this voltage transformation, will be off load or off circuit changing).
Apologies - it seems my earlier post was incorrect, OMS deals with more of this HV stuff for his day job, I have met such things but occasionally, so he will be better informed.
Note then the impedance will vary a bit as the tap changes, but even so only at the 5 % of 5% sort of level. (you cannot alter the volts per turn much, or the core losses go out of whack)
(However, 1960 era transformers with manually bolted taps can be found on the LV side, as at the University they were just that. Equally that transformer caught fire in 1995 apparently, so maybe that is an obsolete way of doing it or it was a special design for that installation - perhaps physics depts just have some funny requirements)
