A CCM/DCM Hybrid Control Scheme for Single Channel Boost PFC Converter to Improve Power Quality

The proposed work intends to design a single channel boost power factor correction (PFC) AC to DC converter for wide range of power applications. Unlike the traditional approaches of PFC this topology manages to eliminate the ripple in input as well as in output current and voltage waveforms, reduces peak current and switching losses. Conventional controllers cannot obtain a good current shaping because of non-linear characteristics of converter at light loads and inaccurate average current samples in DCM mode. This inappropriate current profile also causes poor efficiency. A new digital hybrid control scheme which includes the sampling correction during reference current generation is employed for shaping the good input current in both CCM/DCM mode and also allows the smooth transition between two modes as the load changes. The proposed scheme also improves the reference current tracking at low load conditions. A satisfactory performance of 1KW PFC converter working at 50 KHz switching frequency with hybrid CCM/DCM control scheme is validated by simulation results at various load conditions. The obtained results of power indices comply with IEEE 519-1992 and IEC 61000-3-2 standards.