The power factor (PF) is a critical parameter in AC circuits that measures the ratio of active power to apparent power, indicating how efficiently electrical energy is being used. An ideal value is 1.0, meaning voltage and current are in phase with no reactive losses. In real systems, especially those with inductive loads (e.g., motors, transformers), it is typically less than 1.0.
This tool calculates the power factor based on input parameters such as voltage, current, active power, reactive power, or impedance, supporting single-phase, two-phase, and three-phase systems.
| Parameter | Description |
|---|---|
| Current Type | Select circuit type: • Direct Current (DC): Constant flow from positive to negative pole • Single-phase AC: One live conductor (phase) + neutral • Two-phase AC: Two phase conductors, optionally with neutral • Three-phase AC: Three phase conductors; four-wire system includes neutral |
| Voltage | Electric potential difference between two points. • Single-phase: Enter **Phase-Neutral voltage** • Two-phase / Three-phase: Enter **Phase-Phase voltage** |
| Current | Flow of electric charge through a material, unit: Amperes (A) |
| Active Power | Actual power consumed by the load and converted into useful work (heat, light, motion). Unit: Watts (W) |
| Reactive Power | Energy alternately flowing in inductive/capacitive components without conversion to other forms. Unit: VAR (Volt-Ampere Reactive) |
| Apparent Power | Product of RMS voltage and current, representing total power supplied. Unit: VA (Volt-Ampere) |
| Resistance | Opposition to DC current flow, unit: Ohm (Ω) |
| Impedance | Total opposition to AC current, including resistance, inductance, and capacitance. Unit: Ohm (Ω) |
Power factor is defined as:
Where:
- P: Active power (W)
- S: Apparent power (VA), S = V × I
- φ: Phase angle between voltage and current
Alternative formulas:
Where:
- R: Resistance
- Z: Impedance
- Q: Reactive power
Higher power factor means better efficiency and lower line losses
Low power factor increases current, reduces transformer capacity, and may incur utility penalties