Power-Factor Correction kvar
Also known as capacitor bank sizing · PF correction
Worked example: 100 kW from 0.70 to 0.95 PF → 69.15 kvar — press Try an example to run it live, then adjust anything.
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UniversityCircuits & Electrical Power
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Power-Factor Correction kvar explained
Each power factor corresponds to a phase angle φ = arccos(PF), and the reactive burden of a load is P tan φ. To move from a poor PF₁ to a target PF₂ you must cancel the difference in those vars, which is what a capacitor bank does. A 100 kW plant at 0.70 PF carries 100 × 1.020 = 102 kvar; at 0.95 PF it would carry only 32.9 kvar, so about 69 kvar of capacitors closes the gap.
Two field cautions. Chasing unity is a mistake — the last few points cost the most capacitors, and an overcorrected plant goes leading, which can push voltage up and, on a motor that keeps spinning after the contactor opens, cause damaging self-excitation. And where the harmonic content is high, plain capacitors resonate with the supply inductance and amplify the harmonics; detuned reactors are then part of the package.
Power-Factor Correction kvar formula
- = Correction reactive power (var) (W)
- = Load real power (W)
- = Existing power factor
- = Target power factor
Missing one of these? Work it out first, then come back
- Correction reactive power (var) — Reactive Power (Power Triangle), Power-Factor Correction Capacitance
- Load real power — Three-Phase Real Power, Single-Phase Real Power with Power Factor
- Existing power factor — Three-Phase Real Power, Single-Phase Real Power with Power Factor
- Target power factor — Three-Phase Real Power, Single-Phase Real Power with Power Factor