Multi-level converters for low voltage high current applications: Issues, challenges and limitations

Low voltage and high current power electronic converters are receiving increasing interest of both industry and academia for their application in stand-alone electric power generating systems. Multi-level converter topologies are well adopted solutions in high voltage applications, however benefits related to the reduction of current and voltage ripple as well to the decrease of switching power losses can be achieved also in low voltage systems. The paper investigates the application of converters with multi-level configurations in automotive systems and two cases are studied. The first case is a DC-DC converter for dual-voltage automotive architecture, while the second case is a low voltage three-phase rectifier for 1kHz AC fundamental frequency electrical generator in auxiliary power supply units.