Power Energy
Power Factor Correction
Power factor correction reduces the reactive power drawn from the supply by adding a compensating reactance, usually a capacitor bank for an inductive load. The required reactive power is the active power multiplied by the difference between the tangents of the initial and target phase angles. Correcting the power factor reduces the supply current and the associated losses, but it must be engineered for the actual load and harmonic conditions.
Power Factor Correction
Q_c = P × (tan φ1 − tan φ2)
Variables and units
| Symbol | Quantity | Unit |
|---|---|---|
| Q_c | Reactive power to compensate | var |
| P | Active power | W |
| φ1 | Initial phase angle | degrees |
| φ2 | Target phase angle | degrees |
Conditions of application
Sinusoidal steady state and approximately constant active power. The compensation capacitor must be rated for the system voltage and for the harmonics present; a detailed study is required where harmonics are significant.
Worked example
Solved
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