| Traditional diode or thyristor rectifiers draw harmonic current from the utility line,which pollutes utility system, disturbs appliances in the transmission capacity. So improvingthe traditional AC/DC converter, increasing the power factor and eliminating the currentharmonics are very important to us. Power-Factor-correction (PFC) techniques have receivedgreat attention in recent years. Three-phase PFC rectifiers are preferred for high powerapplications. In this thesis, a One-Cycle controlled three-phase single-switch DCM boostrectifier is described. At first, we reviewed the high power factor techniques around the world. Then, afterintroducing the operating principle of One-Cycle controlled three-phase single-switch DCMboost rectifier, the reason why the proposed circuit can reduce the input line currenttotal-harmonic-distortion (THD), improving the power-factor and characteristics of thewhole system is also given. The famous CAD simulation software toolkit PSPICE is used tosimulate the propose circuit. Based on the simulation waveforms, an experimentalinstallation is given. Finally, the experimental waveforms and results are given. Converter controlled by One-Cycle control method operate at constant switchingfrequency, require no current sensing, have a simple control circuit, and exhibit resistiveinput impedance at the ac side, meanwhile a periodic voltage is injected in the control circuitto vary the duty cycle of the rectifier switch a line cycle so that 5th-order harmonic of theinput current is reduced. In conclusion, the correctness and feasibility of this One-Cycle controlled three-phasesingle-switch DCM boost rectifier are proved by our theoretical analyses, simulationresearch and experimental validation. The input power factor of the converter is very high,almost 1.
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