voimakertoimia

Voimakertoimia, the Finnish term for power factors, refer to the ratio of real power flowing to a load to the apparent power in an electrical circuit. The value, ranging from –1 to 1, indicates how effectively electrical power is being converted into useful work. A power factor of 1 (unity) means all supplied power is used efficiently, while lower values signify that a portion of power is wasted due to reactive components, such as inductors and capacitors, which store and release energy rather than dissipate it.

In alternating current (AC) systems, current and voltage are not always in phase. The phase difference, measured in degrees, determines the reactive power component. When inductive loads dominate, voltage lags current, producing a lagging power factor; capacitive loads cause voltage to lead current, resulting in a leading power factor. Equipment such as transformers, motors, and fluorescent lighting typically exhibit lagging power factors, whereas power factor correction devices—often banks of capacitors—are installed to reduce reactive power and raise the power factor toward unity.

Electrical utilities often bill consumers based on apparent power consumption and apply penalties for power factors below a regulatory threshold (commonly 0.90 or 0.95). Improving the power factor reduces load on generation and transmission systems, decreases line losses, and can lead to lower electricity costs. Standardized tests, such as the four-corner method, are used to measure power factors accurately in industrial and commercial settings.