Two-Phase Interleaved Boost PFC Converter With Coupled Inductor Under Single-Phase Operation

When the interleaved boost power-factor correction (PFC) converter operates in a light load (<15% of nominal load), the phase-shedding control is commonly used to increase the converter's efficiency. If the inductors are coupled for high power density applications, because of the strong mutual effects of the coupled inductor, the switching of the operation phase may lead to a current flowing in the non-operation phase. In this paper, a two-phase interleaved boost PFC converter with a coupled inductor in the single-phase operation was analyzed. The operation modes of the converter in a switching cycle and a half line cycle were presented, and the modes' variationwith the load changes, as well as the power distribution, was provided. A 1-kW prototype was built to verify the analysis, and it was shown that the non-operation phase also delivers some power, which may worsen the converter's efficiency and distort the average input current waveform.