Power Factor Calculation Formula

Power Factor Formula:

\[ PF = \cos(\theta) = \frac{\text{Real Power}}{\text{Apparent Power}} \]

Power Factor (PF):

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1. What is Power Factor?

Power Factor (PF) is the ratio of real power to apparent power in an AC electrical system. It represents the efficiency of power usage and indicates how effectively electrical power is being converted into useful work output.

2. How Does the Calculator Work?

The calculator uses the power factor formula:

\[ PF = \cos(\theta) = \frac{P}{S} \]

Where:

\( PF \) — Power Factor (dimensionless)
\( \theta \) — Phase angle between voltage and current (radians or degrees)
\( P \) — Real Power (Watts)
\( S \) — Apparent Power (Volt-Amperes)

Explanation: Power factor ranges from 0 to 1, where 1 represents perfect efficiency (all power is real power) and 0 represents poor efficiency (all power is reactive power).

3. Importance of Power Factor

Details: Power factor correction is crucial in electrical systems to reduce energy costs, improve voltage regulation, increase system capacity, and reduce power losses. Utilities often charge penalties for low power factor in industrial and commercial settings.

4. Using the Calculator

Tips: You can calculate power factor using either real/apparent power values or phase angle. Enter values in appropriate units (Watts for real power, VA for apparent power, degrees for phase angle). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a good power factor value?
A: Generally, power factor above 0.95 is considered good. Values below 0.85 may incur utility penalties in commercial/industrial settings.

Q2: What causes low power factor?
A: Inductive loads like motors, transformers, and fluorescent lighting cause current to lag voltage, resulting in low power factor.

Q3: How can power factor be improved?
A: Power factor correction capacitors, synchronous condensers, or active power factor correction circuits can be used to improve power factor.

Q4: What's the difference between real, apparent, and reactive power?
A: Real power (Watts) does useful work, apparent power (VA) is the vector sum of real and reactive power, and reactive power (VAR) creates magnetic fields but does no useful work.

Q5: Does power factor affect residential electricity bills?
A: Typically not for residential customers, but commercial and industrial customers often pay power factor penalties for values below 0.90-0.95.