Power factor

In alternating current power, the ratio of active power to apparent power is expressed by the following formula.

Active power / Apparent power
or
(Active power / Apparent power) × 100 (%)

It indicates the shift of the current waveform relative to the voltage waveform. If it leads, it is called a leading power factor; if it lags, it is called a lagging power factor. The degree of lag is determined by the proportion of L (inductance) components in the electrical circuit, and the degree of lead is determined by the proportion of C (capacitance) components. If there are no LC components, the power factor becomes 1 (100%). In power transmission and distribution circuits, it is necessary to increase the power factor to about 0.8 (80%) to effectively use power lines and reduce losses. In order to improve a lagging power factor, a power factor correction capacitor is grounded.