Three-phase unidirectional buck-type third harmonic injection rectifier concepts

This work introduces three-phase unidirectional buck-type unity power factor rectifiers. The proposed rectifiers are assembled by incorporating auxiliary circuit branches into standard three-phase buck-type PFC topologies, each comprising an active switch and three diodes. These circuits can operate as active third harmonic current injection PFC systems. The characteristics of the buck-type converters, including their operation principle, appropriate modulation strategy and control structure, are described. The proposed converters are compared to state-of-the-art buck-type rectifiers. According to the results, the proposed rectifiers can achieve the highest efficiency and thus are the topology of choice for a 2.5 kW three-phase buck-type PFC rectifier.