Analysis and Implementation of A Single-Stage High Power-Factor Converter

• Main Authors: HuangYen-Chang, 黃彥彰
• Other Authors: Shin-Ju Chen
• Format: Others
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/22848293184799004496

碩士 === 崑山科技大學 === 電機工程研究所 === 95 === A single-stage high power-factor converter combined by the buck-boost and flyback converters is studied in this thesis. The combined process of the converter is presented. The converter exhibits high power-factor inherently without external current control when it operates under DCM+DCM mode. Moreover, the high voltage stress of the bulk capacitor does not exist. Based on the loss-free-resistor (LFR) model, the state-space averaging method, harmonics balance method and TL-model method are used to obtain the dc values, voltage ripples and phase angle shift for the bulk capacitor and output voltage in the steady-state analysis.The results of IsSpice simulation are used to verify theoretical analysis. The two-time scale averaging method and current injected equivalent circuit approach are used to derived the small signal model and obtain the coincide results. The theoretical results are verified by the experimental measurements of dynamic signal analyzer (Agilent 35670A).Eventually, a controller is designed to eliminate the effect of the variations of line voltage and load on the output voltage. A prototype of the converter with input voltage 110 Vrms, output voltage 48 V and maximal power 100 W is implemented. The performances of high power-factor, low bulk capacitor voltage stress and well output voltage regulation are verified by experimental measurements.