Single-stage AC-DC converter with PFC based on continuous input current charge-pump topologies

Abstract

This paper presents a single-stage power factor corrected (PFC) AC-DC converter. The topology is based on CIC-CPPFC (continuous input current charge-pump power factor correction) technique, achieving continuous conduction mode (CCM) input current with high power factor by using a coupled inductor, meeting IEC 61000-3-2 regulations for wide load range without additional input filter. Two different switching laws are tested. The first is complementary command with constant duty cycle of 50% and variable switching frequency and the second is the conventional (half-bridge) PWM. In the first case the converter operates with zero voltage switching (ZVS) resulting in high efficiency for a wide load range. The second allows the use of commercial command circuitry, reducing the cost. It is also a cost effective and competitive solution for low power applications where a two stage approach is costly and passive filters are not recommended. Another feature is the reduction of the DC-link capacitor, reducing costs and presenting a significant advantage over many single-stage solutions.