Reactive power is the energy alternately flowing in inductive and capacitive components of an AC circuit without being transformed into other forms of energy. Although it does not perform useful work, it is essential for maintaining voltage stability and system performance. Unit: Volt-Ampere Reactive (VAR).
Current Type
Select the type of current:
- Direct Current (DC): Constant flow from positive to negative pole; no reactive power
- Alternating Current (AC): Reverses direction and amplitude periodically at constant frequency
System configurations:
- Single-phase: Two conductors (phase + neutral)
- Two-phase: Two phase conductors; neutral may be distributed
- Three-phase: Three phase conductors; four-wire system includes neutral
Note: Reactive power only exists in AC circuits.
Voltage
Electric potential difference between two points.
- For single-phase: Enter Phase-Neutral voltage
- For two-phase or three-phase: Enter Phase-Phase voltage
Current
Flow of electric charge through a material, measured in amperes (A).
Active Power
The power actually consumed by a load and converted into useful energy (e.g., heat, motion).
Unit: Watts (W)
Formula:
Apparent Power
The product of RMS voltage and current, representing total power supplied by the source.
Unit: Volt-Ampere (VA)
Formula:
Power Factor
Ratio of active power to apparent power, indicating efficiency of power usage.
Formula:
where φ is the phase angle between voltage and current. Value ranges from 0 to 1.
Resistance
Opposition to current flow due to material properties, length, and cross-sectional area.
Unit: Ohm (Ω)
Formula:
Impedance
Total opposition of a circuit to alternating current, including resistance, inductive reactance, and capacitive reactance.
Unit: Ohm (Ω)
Formula:
Reactive power \( Q \) is calculated as:
or:
Where:
- S: Apparent power (VA)
- P: Active power (W)
- φ: Phase angle between voltage and current
If the circuit is inductive, Q > 0 (absorbs reactive power); if capacitive, Q < 0 (supplies reactive power).