Rated capacity of three-phase transformer S = √3 * U * I
So, when calculating the three-phase load, U is the line voltage, and I is the line current. S = 1.732 (root 3) UI.
S = 3UI. Where U is the phase voltage and I is the phase current.
S = 1.732UI where U is the line voltage and I is the line current.
Two methods, the same result.
Single phase transformer S = UI where U is the phase voltage and I is the phase current.
When the composition of three-phase transformer, of course, is the three transformers add up, S = 3UI. Here U is phase voltage, I is the phase current.
As the three-phase circuit to use the line current and line voltage calculation, angle and triangular connection is the same, when U is the line voltage, the phase voltage increases the root number 3 (1.732) times.
S is the total capacity of the three phases, is the apparent power, the unit is KVA.
The sum of the three phases is equal to the sum of the three single-phase capacities, ie S = 3UI where U is the phase voltage and I is the phase current.
If the line voltage line current, then S = √3UI
This is because when the winding is triangular connected, the line voltage is equal to the phase voltage, the phase current is equal to 1 / √3 times the line current, 3 / √3 =
Similarly, when the star is connected, the phase current is equal to the line current, the phase voltage is equal to 1 / √3 times the line voltage, the same 3 / √3 =
