K.J. wrote: Power in single-phase systems
P = U × I × cosφ = Uf × If × cosφ
Although the markings are unambiguous here, the repetition of the notation implies that:
U•I = U f •AND f , but this equality does not necessarily imply a double equality that;
U = U f , and;
I = I f .
K.J. wrote: Power in three-phase systems
P = U × I × cosφ = √3 × Uf × If × cosφ
where: Uf= 230V U=√3 × 230V ≈ 400V
It's some
new Theoretical Electrical Engineering Is... :cry:
In three-phase systems, the measurement (calculation) of active power should be clearly differentiated
P for the layout
symmetrical three-phase and active power for the system
unbalanced three-phase ...
The parameters on the terminals of a three-phase and three-wire receiver (with an unknown connection inside this three-port) are:
- line voltages
AT p - between the next three pairs of wires,
- conductor currents
AND p - flowing in each of the three conduits.
Only in the case of a three-phase and symmetrical receiver (but then in the neutral - neutral - no current flows and it does not matter whether it is a three- or four-wire system) you can use the following formula:
P = √3•U p •AND p , while in the case of asymmetry, the powers in the individual phases of the receiver should be measured (counted) and summed up, or (but only for three-wire receivers) used to measure the sum of active power
Arona system (two wattmeters respectively connected to the circuit).
