Variables
Description
What is this formula?
This formula calculates the reactive power supplied by a capacitor bank connected to an AC electrical system.
When to use it
Use this formula when designing power factor correction systems, sizing capacitor banks, reducing reactive power demand, and improving electrical system efficiency.
Example
A capacitor bank operates at:
Frequency = 60 Hz
Capacitance = 200 μF
Voltage = 480 V
Convert capacitance:
C = 200 × 10^-6 F = 0.0002 F
Formula:
Qc = 2πfCV²
Substitution:
Qc = 2 × π × 60 × 0.0002 × 480²
Result:
Qc = 17,377 var
Qc ≈ 17.4 kVAr
Applications
Power factor correction
Industrial electrical systems
Utility reactive power reduction
Capacitor bank sizing
Electrical energy optimization
Note
This equation assumes a sinusoidal steady-state AC system and an ideal capacitor. Practical capacitor banks may include losses, harmonic filters, switching devices, and voltage tolerances that slightly affect the actual reactive power supplied.