Ractical design estimation of the output filter for half-controlled thyristor converters in power supply and battery charger applications

Simple formulas for practical design estimation of filter inductor and capacitor for single-phase as well as three phase half-controlled thyristor converters with series filter inductor and a bulk capacitor or a battery in parallel with the load are developed. The filter inductor estimation includes minimum inductance necessary for continuous current operation as well as ratios between average, peak, RMS, and peak-to-peak ripple values of the current as a function of the firing angle and inductance value. The filter capacitor estimation includes minimum capacitance necessary for rated ripple voltage and RMS current thru the capacitor.