Everything About ___
Live briefing

Everything about Power factor

Ratio of active power to apparent power

In electrical engineering, the power factor of an AC power system is defined as the ratio of the real power absorbed by the load to the apparent power flowing in the circuit. Real power is the average of the instantaneous product of voltage and current and represents the capacity of the electricity for performing work. Apparent power is the product of root mean square (RMS) current and voltage. Apparent power is often higher than real power because energy is cyclically accumulated in the load and returned to the source or because a non-linear load distorts the wave shape of the current. Where apparent power exceeds real power, more current is flowing in the circuit than would be required to transfer real power. Where the power factor magnitude is less than one, the voltage and current are not in phase, which reduces the average product of the two. A negative power factor occurs when the device generates real power, which then flows back towards the source. Wikipedia →

🧭 Start here: a 6-step reading path

  1. Read the overview: Power factorA 5-minute orientation
  2. Skim a recent paper: Thermoelectric power factor of compositesInfluential work since 2022
  3. Pick up a classic book: Human-system interface design review guidelinesThe most-reprinted book on the subject
  4. Read the landmark paper: Active Power Factor Correction for Switching Power SuppliesCited 87 times
  5. Go sideways: AC powerA closely related topic
  6. Go sideways: Harmonics (electrical power)A closely related topic

📖 Definitions

Noun The ratio of the actual power to the apparent power in an alternating current power system; specifically, the cosine of the phase angle between the voltage and the current.

🗂️ The subject at a glance

  1. General case
  2. Linear circuits
  3. Non-linear loads
  4. Importance in distribution systems
  5. Measurement techniques
  6. Mnemonics

🏆 Landmark papers (most cited)

🆕 Influential since 2022

📚 Books worth reading

Ranked by number of editions on Open Library, a rough measure of how lasting a book is.

🔗 Related topics