Reduced Diode Clamped Multilevel Converter with a modified control method

This paper presents a new configuration of Neutral-point-clamped (NPC) or Diode Clamped converters called Reduced Diode Clamped Multilevel (RDCM) Converter. In this topology, the number of clamping diodes and high frequency switches are decreased while the voltage ratings of them during a full cycle are kept constant. Compared with conventional NPC or Diode Clamped converters, The main advantages of the proposed converter are increasing the effective value and the number of output voltage levels up to twice, improving the output voltage frequency spectrum and lowering the number of components which can result in the decreasment of the converter´s size and cost. These improvements are achieved by adding only two low-frequency switches to a Half-bridge Diode-Clamped Multilevel converter configuration. Also, This converter is controlled by a modified pulse width modulation PWM based control method. The circuit is simulated using PSCAD/EMTDC software and simulation results are presented to validate the effectiveness and advantages of the proposed configuration.