Modulation and Control of a Three-Phase Phase-Modular Isolated Matrix-Type PFC Rectifier

Three-phase phase-modular isolated power factor correction rectifiers are an interesting alternative to phase-integrated three-phase rectifiers as matrix-type phase modules allow a single-stage isolated energy conversion between the three-phase mains and a dc bus. Therefore, this paper presents a phase-modular isolated matrix-type rectifier which can be connected to the mains either in star (Y) or delta (Delta) configuration, enabling a wide input voltage range. Additionally this allows to select the voltage and current stresses of the phase module switches according to the used semiconductor technology, for example 650 V Si or GaN devices could be used in rectifiers powered from the 400 or 480 V-rms mains. A detailed analysis of the operating principles and switching behavior of the converter is presented, showing that zero voltage switching can be achieved in the phase modules. Additionally a third harmonic current injection concept is proposed which allows an up to 15% higher output voltage in Delta-mode. The concepts are validated with measurements taken on a 7.5 kW, 400 V dc output voltage prototype converter achieving 97.2% efficiency and a total harmonic distortion of < 2% at rated power.