Design and Implementation of Single Stage Bridgeless SEPIC Power Factor Corrected AC-DC Converter

Abstract

Due to increase in modern power electronic systems the more emphasis is put on power quality. Nowadays, DC power supplies are widely used in most electronic equipment such as computers, battery chargers, variable frequency drives, and switch mode power supplies. The most commonly used AC-DC power supply configuration is diode bridge rectifier with bulk capacitor. This configuration involves substantial harmonics into the input side current resulting in poor power quality due to low power factor and high harmonic distortion. In fact, the substantial harmonics does not meet the regulatory standards such as IEC610000-3-2, forcing to pay attention on Power Factor Correction (PFC). Problems caused by power quality have a great adverse economy effect on both utilities and customers. Active PFC schemes are most effective methods to mitigate the harmonics and improve the power quality. For medium to high power applications power factor correction has become compulsory in order to comply with regulatory standards.


In this work, four single stage bridgeless single ended primary inductance PFC converters are discussed and shares common objective to provide power factor correction and output voltage regulation. The purpose of this work is to reduce the voltage stress and current stress on the components of the converter. This work includes configurations of bridgeless SEPIC converter operating under continuous conduction mode (CCM) to overcome the drawbacks of discontinuous conduction mode (DCM) since for medium and high power applications CCM is the primary choice. On the whole, in this work, theoretical analysis, design and construction of a 300 W continuous conduction mode (CCM) PFC circuit prototype is presented and discussed. Simulation and experimental results are presented to verify the theoretical analysis.