Modified SVPWM-Controlled Three-Port Three-Phase AC–DC Converters With Reduced Power Conversion Stages for Wide Voltage Range Applications

Three-port three-phase rectifiers (TPTPRs) are proposed by introducing a new low-voltage (LV) dc power port into the three-phase six-switch boost rectifier. An ac input port, an LV dc load port, and a high-voltage (HV) dc bus port are provided simultaneously by TPTPRs. A dc load, whose voltage is lower than the peak amplitude of the ac line voltage and varies over a wide range, can be connected to the LV dc load port of the TPTPR directly. A modified space vector pulse width modulation (SVPWM) strategy is proposed for the TPTPR to accomplish voltage and current regulations, based on which part of the ac input power can be directly fed to the LV dc load within single power conversion stage. As a result, the power rating and losses of the downstream dc-dc converter, which is connected to the HV dc bus port of the TPTPR, are reduced significantly. The conversion efficiency of the TPTPR-based ac-dc converter benefits not only from the reduced power conversion stages, but also from the reduced switching losses due to the multilevel characteristics of the TPTPR. Operation principles and characteristics of the proposed TPTPRs and modified SVPWM strategies are analyzed in detail and verified with experimental results.