Two transformers of same rating & Voltage ratio; One with lesser % Impedance & other with higher % Impedance. What does it signify & what is the constructional difference between them?
If the impedance will be different even after same Rating & Voltage Ratio,then the Transformers will be completely different both from Electrical as well as Mechanical point of view.
1)Wdg will be different from Height ,material
2)Main Tank will be different,so overall dimensions will be changed.
3)OLTC connections will be different.
4)Cores will be different.
There will be change in the BUshing Data if you add the difference in BASIC INSULATION LEVEL also.
I think a little more detailed info is required here. First, see the following for a simple explanation of transformer impedance. Also do a search in CR4 - there have been several good threads on this issue.
Then, to elaborate on the above points:
1. Winding may be different material, depending on what is chosen (aluminum, copper). Height also may be different depending on the design chosen for the transformer's core & coils. Because of higher short-circuit capability of a lower impedance trafo, the winding insulation, bracing, and blocking might need to be reinforced.
2. The main tank may be different based on #1, but could be the same.
3. There is no reason OLTC should be different, because the taps will still have the same # of steps and % difference between them, unless you specify differently.
4. Core could be different based on #1, but will not necessarily be so just because of %Z change.
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Transformers
Re: Transformers
