Development of three-phase three-level high power factor diode clamped AC/DC converter for electric vehicle fast charging system

As electric vehicle users are concerned about the charging time and range of their vehicles, researchers are turning their attention to improving the charging infrastructure. This thesis first presents a comprehensive literature review of the multilevel converter topologies and modulation techniques considered for fast charging stations. Then, a three-level diode clamped power factor regulator topology with various hybrid frequency modulation techniques is discussed with simulation studies for a 300 kW fast charging system. It is very important that the output current and voltage ripple of the diode clamped rectifier considered for application in fast charging stations are within IEEE standards, the rectifier maintains the neutral point voltage balance, the current harmonic drawn from the grid is below 5%, the power factor is 1 and the rectifier operates efficiently. Accordingly, a new modified carrier-based hybrid frequency DGM method is proposed for the rectifier considered in this study to operate in accordance with the standards. A software has been developed for the proposed method using the TMS320F28379D digital signal processor. The proposed method is tested on a low power three-phase three-level 3L-SKiiP28MLI07E3V1 power module. The validity and flexibility of the modified level-shifted hybrid frequency DGM method are emphasized.