What is the formula for three-phase real power (P)?

The correct answer for the formula for three-phase real power (P) is rooted in the understanding of power in three-phase systems. The formula P = √3(IVpf) incorporates several essential components:

1. I represents the line current flowing through the system.
2. V signifies the line-to-line voltage in a three-phase system.
3. pf denotes the power factor, which is a measure of the phase difference between voltage and current waveforms in AC circuits. A power factor of 1 (or close to it) indicates that the current and voltage are in phase, leading to maximum real power use.

The factor of √3 arises because, in a three-phase system, the total or real power is equal to the square root of three times the phase voltage, current, and the power factor. This √3 factor comes into play when converting between line voltage and phase voltage in a wye configuration and is essential for correctly calculating the total real power supplied to a load or consumed by the system.

Understanding this formula is crucial in electrical engineering, primarily when working with three-phase systems, as it helps in determining how much actual power is being converted to useful work or heat, which is necessary for efficient electrical design