Investigation of a single phase unidirectional switch mode cuk power factor corrected (PFC) rectifier

Abstract

Singlephasedioderectifiersarewidelyusedin industrial, commercial, utility and domesticapplications.Manyinputwaveshapingmethodshavebeenproposedtosolvetheproblem ofpoorpowerfactorwhichcanbeclassifiedasactiveandpassivemethods.Four different configurations based on single phase C ̂uk topologies have been proposed to solve poor input power factor and total harmonic distortion problems of AC-DC converters. The proposed topologies show superior performance over output voltage regulated conventional single phase AC-DC converters. The topologies proposed are Input Switched C ̂uk Converter (output full bridge), Input Switched C ̂uk Converter (output half bridge), Modified C ̂uk Converter-1 (Switch within a Diode Bridge), Modified C ̂uk Converter-2 (Switch within a Diode Bridge) configurations. The proposed configurations are designed for operating the converters both buck and boost voltage gain region. Results are compared with the results of conventional output switched single phase boost rectifier andconventional output switched Ĉuk rectifier. Proposed topologies show lower input current THD, higher power factor and high efficiency compared to the previously mentioned conventional rectifiers. Typical output voltage and input current waveforms are shown in the thesis work. It has been found that without feedback control input current THD is not in acceptable range. Therefore a feedback controller is designed in this thesis work which makes the power factor of the rectifier above 0.9 and keeps the input current THD less than 10%. The feedback controller with the power stage of the proposed topologies are also designed in such a way that gives regulated output voltage with load variation. The results show that, the proposed configurations based on C ̂uk topologies give better performance over all the conventional output switched and input switched boost rectifiers and also output switched C ̂uk rectifier.