Three Phase Power Calculator

The three-phase power calculator calculates the apparent, active and reactive power for three-phase AC systems.

Power Triangle Diagram

Power Triangle Diagram showing relationship between Active, Reactive, and Apparent Power

1. Apparent Power (S)

Apparent power represents the total power delivered to a circuit. In three-phase systems, it's calculated using:

\[S = \sqrt{3} \times V_{L-L} \times I\]

Where:

  • \(V_{L-L}\): Line-to-line voltage (V)
  • \(I\): Line current (A)
  • \(\sqrt{3}\): Three-phase constant (≈ 1.732)

Unit: Volt-Ampere (VA)

2. Active Power (P)

Active power, also known as real power, represents the actual power consumed by the load to perform useful work:

\[P = S \times pf\]

Where:

  • \(S\): Apparent power (VA)
  • \(pf\): Power factor (0 to 1)

Unit: Watt (W)

3. Reactive Power (Q)

Reactive power is the power used to maintain electromagnetic fields in inductive or capacitive loads:

\[Q = \sqrt{S^2 - P^2}\]

Where:

  • \(S\): Apparent power (VA)
  • \(P\): Active power (W)

Unit: Volt-Ampere Reactive (VAR)

Key Points

  • Power factor (pf) indicates how efficiently electrical power is being used
  • Higher power factor (closer to 1) means more efficient power usage
  • Lower reactive power generally indicates better system efficiency