I have a 5500/380V Dyn11 transformer, with possible tap settings of 0.95, 0.975, 1.00, 1.025 and 1.05 on both primary and secondary side.
Due to high loading, I want to change the tap settings to either 0.975/1.00, or 1.00/1.025. However, I'm not sure on what side of the transformer I should change the setting.
My intuition tells me that it makes more sense to select the primary side, but I'm not certain.
- One reason for changing the setting on the primary side is: The current is much higher on the secondary side, thus increasing the number of windings there will cause higher losses.
- Another one: More windings might lead to saturation (I would however think that the transformer was designed so that this won't be a problem).
Does the transformer type play a role? Does it matter if the transformer is Dy, Yd, Dd, Yy etc? How will it affect the impedance?
Will there be any side-effects of selecting one or the other? Are there any reasons for choosing to change the settings on the secondary side?