Power factor correction with a partial power processing converter

Abstract

When a power system needs power factor correction and fast output voltage regulation, two main possibilities arise: to use two converters connected in cascade or to use a single converter performing both things. In the first case, each converter performs a different function; the first one corrects the power factor and the second one provides fast output voltage regulation. With this option, the total power is processed twice. In the second case, a single converter achieves both specifications. In this case, the power is processed less than twice by the converter looking for a better efficiency. This paper presents a hybrid method to correct the power factor achieving fast output voltage regulation. Two converters are used but the one in charge of reducing the input current harmonic content only process a small part of the total power. Apart from the high efficiency of the system, the main advantage is that the voltage across the bulk capacitor can be equal to the peak input voltage. Furthermore, the second converter is completely independent and can be chosen among all existing converters. The main drawback is that this system is slightly more complex than a single stage converter. A prototype for a 500 W application has been built and tested to study the real performance of this system.