Active filter for charging rectifiers used in power supplies

The paper proposes an active filter (AF) for power supply systems based on an CRD HPT 160.220 one-piece charging rectifier. Harmonic components here are compensated by a half-bridge single-phase voltage inverter circuit. The converter produces a harmonic component, which is phase-opposite to the harmonics present in the charging rectifier output signal. The AF is series-connected to the rectifier output circuit via a matching transformer with few winding turns. The paper proposes a method for designing an active filter with a control system. It presents a calculation of analog lowpass and highpass filters (second-order Bessel). The charging rectifier has been tested filtered and unfiltered at various rectifier output voltages. The paper presents current and voltage plots for the main AF circuit points as obtained by simulation.