Three-Phase Rectifier Output Calculator

A six-pulse rectifier — a three-phase full-wave diode bridge — produces a DC output whose average value is V_dc = (3√2/π) · V_LL ≈ 1.35 · V_LL, where V_LL is the RMS line-to-line AC input voltage. Because the bridge commutates between six line-to-line voltage segments per cycle, the ripple frequency on the output is six times the AC supply frequency (360 Hz on a 60 Hz supply), which is both a much higher ripple frequency and a much smaller ripple magnitude than a single-phase rectifier of the same rating — one of the main reasons three-phase rectification is used for anything beyond small power levels.

This calculator also reports the peak inverse voltage (PIV) each diode must block — √2 · V_LL for a three-phase bridge — and, if you provide a load resistance, the resulting DC current and power delivered to the load.

This is the ideal, unloaded-commutation case: it assumes zero source impedance (instantaneous commutation between diodes), ideal diodes with no forward voltage drop, and a purely resistive load. Real source impedance causes commutation overlap that reduces average DC voltage below the ideal value, and diode forward drop further reduces it — both effects grow with load current. For a precise design, add a commutation-overlap correction and diode drop allowance on top of this ideal-case result.