Novel three-phase high-quality multi-resonant rectifiers operating with zero-current-switching and constant switching frequency

Novel three-phase high-quality multi-resonant rectifiers, operating at constant switching frequency is proposed. The input diode-bridge and two switches in these rectifiers operate under zero-current switching (ZCS) condition, while the dc-side diode operates under zero-voltage switching (ZVS) condition. The voltage stress on the devices is independent of the variations in load-current. The proposed rectifiers emulate resistive characteristics resulting in high-quality input current and are suitable for applications in which high efficiency and high power density are required. Also, output power can be controlled from zero to the rated. The validity of proposed concept is verified by taking an example of three-phase boost-type multi-resonant rectifier circuit. Averaged model of this circuit is derived. Performance of the circuit is predicted by simulating it on SABER. A laboratory prototype delivering 1 kW at 250 volts from 120 V_{rms (L-L)} is designed and developed. The simulation results are verified experimentally.