New single-switch three-phase high-power-factor rectifiers using multiresonant zero-current switching

A new family of single-switch three-phase high-power-factor rectifiers, which have continuous input and output currents, is introduced. By using a multiresonant scheme, the transistor operates with zero-current switching (ZCS), and the diodes operate with zero-voltage switching (ZVS). These multiresonant rectifiers with a single transistor are capable of drawing a higher quality input-current waveform at nearly unity power factor and lower stresses than quasi-resonant rectifiers. Buck-type converters are used for the power stage, and, hence, the output voltage is lower than the input voltage. Moreover, these rectifiers have a wide load range and low stresses on semiconductor devices. From the analysis, normalized characteristics of the rectifier are derived. The design and breadboard implementation of the rectifier delivering 147 V_dc at 6 kW from a 3φ 240-V _rms(LL) input is described. The total harmonic distortion (THD) of the line current is less than 5%, and the system efficiency is about 94% at the full load