Nominal voltage of equipment
Nominal voltage of equipment
(OP)
The voltage at power equipment terminals usually declines with drawn current causing voltage regulation. With that in mind, I get confused of the relation between transformer %impedance and associated range of tap changer to compensate the regulation?
On other hand, how much current that can be drawn from an equipment (assuming the thermal capability is available) before its terminal voltage falls beyond the operational range? (-10%) can that current be a basis for nominal equipment rating other than thermal capability?
a bit messed up!
On other hand, how much current that can be drawn from an equipment (assuming the thermal capability is available) before its terminal voltage falls beyond the operational range? (-10%) can that current be a basis for nominal equipment rating other than thermal capability?
a bit messed up!






RE: Nominal voltage of equipment
RE: Nominal voltage of equipment
Regulation describes the voltage drop at full load current and a specified power factor.
%Impedance describes the EMF driving current through a short circuit. In this case, the power factor is determined by the X/R ratio of the transformer. That is a much lower power factor than is specified for regulation.
The %regulation is always less than the %impedance. That is, less voltage drop under load than calculations using %impedance will show.
Bill
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"Why not the best?"
Jimmy Carter
RE: Nominal voltage of equipment
a narrow +/-10% range is where the operation takes place.
the curve shows that you can never transfer power more than short circuit MVA, which is logical, but the SC MVA is a huge figure with the fault current multiplied by nominal pre-fault voltage, which can never happen as well!.
RE: Nominal voltage of equipment