Comparative analysis of boost and buck-boost derived topologies used as power factor correctors

AC/DC converters are extensively used in various applications. The electronics equipment uses as an input stage a rectifier with a capacitor as a filter. A major problem associated with these loads are the harmonic currents injected into the power supply and low power factor. The undesirable effects of harmonics distortion and low power factor are well documented. Therefore, it is highly desirable to include power factor correction schemes in the electronics equipment. A boost converter in the continuous conduction mode using the multiplier approach is commonly used as a power factor correction topology due to its excellent performance in medium power. Power factor correction topologies derived from the buck-boost converter have been proposed, mainly because they emulate a natural resistor when operating in discontinuous conduction mode, using a single control loop. Topologies derived from buck-boost converters, are an attractive solution in power factor correction applications in a relatively low power range. This paper presents a comparative analysis between a boost converter in continuous conduction mode and Sepic and Cuk converters in discontinuous conduction mode in order to study their performance in terms of PF, THD, efficiency, semiconductors stress, volume, etc