Single-Tuned Harmonic Filter Design

Size a single-tuned (L–C) filter: tuned frequency, reactor/capacitor sizing, quality factor, and harmonic current (IEC 61642).

Inputs

Reactor inductance L mH

Capacitor C µF

Tune to harmonic h —

Fundamental frequency f₀ Hz

Reactor loss resistance R Ω

System line voltage U_LL V

h-th harmonic voltage U_h V

Results

Note — Tune slightly detuned (≈ +5 to +10% of h·f₀) so the filter does not sit exactly on the harmonic. The capacitor sees a voltage rise ~h²/(h²−1); verify the capacitor kVAr and the reactor against the manufacturer's de-rating. A certified network study is required before energizing.