Definition
PF = kW ÷ kVA
A 100 kVA load using 80 kW has 0.80 power factor. The remaining apparent-power burden is associated with reactive power and, for distorted waveforms, harmonic content.
Why Low PF Increases Current
At fixed real power and voltage, current rises as PF falls. Higher current increases I²R losses, voltage drop, and capacity used in conductors, transformers, generators, and switchgear.
Displacement and True Power Factor
Displacement PF describes phase shift between fundamental voltage and current. True PF also includes waveform distortion. Capacitors can correct inductive displacement PF but do not automatically remove harmonic current.
Capacitor Correction
Capacitors supply leading reactive power that offsets inductive reactive power from motors and transformers. Correction size is based on load kW and the tangent difference between initial and target phase angles.
Harmonics and resonance must be evaluated before applying capacitor banks, especially on systems with drives or rectifiers.