To calculate the total power in a three-phase circuit, you typically need to consider both the real power (active power) and the reactive power. The formula for calculating total power in a balanced three-phase circuit is:
Total Power (P) = √3 × Voltage (V) × Current (I) × Power Factor (PF)
Where:
√3 is the square root of 3 (approximately 1.732)
Voltage (V) is the line-to-line voltage in volts (V)
Current (I) is the line current in amperes (A)
Power Factor (PF) is the cosine of the phase angle between the voltage and current waveforms. It represents the efficiency of the circuit and ranges from 0 to 1, with 1 being fully efficient.
The power factor takes into account the phase difference between the voltage and current waveforms. In an ideal situation where the current and voltage waveforms are perfectly in phase (resistive load), the power factor would be 1, and the circuit would have only real power.
If the circuit has reactive components (inductive or capacitive loads), the power factor will be less than 1, and the total power will be a combination of real power and reactive power. In this case, the total power can be calculated as:
Total Power (P) = √(Real Power² + Reactive Power²)
Where:
Real Power = √3 × Voltage × Current × Power Factor
Reactive Power = √3 × Voltage × Current × √(1 - Power Factor²)
Keep in mind that if you have access to measurements of real power and reactive power directly, you can use those values to calculate the total power more accurately.
Remember to use consistent units for voltage (V) and current (A) in your calculations.