A New Structure of Single-Phase Multilevel Inverter with Reduced Number of Switches and Low Output Harmonics

Multilevel inverters have been widely applied in industries. A new structure of multilevel inverter with reduced number of switches and low output harmonics is proposed in this paper. It consists of an H-bridge inverter and an inverter which produces multilevel voltage by switching DC voltage sources in series. As the number of switches are reduced, both conduction and switching losses will be decreased, which leads to increase in the efficiency of converter. The size and power consumption of driving circuits is also reduced. The proposed inverter can produce more number of voltage levels with the same number of voltage source and reduced number of switches compared to the conventional inverters. The proposed structure minimizes the total harmonic distortion (THD) of the output voltage waveform. Effectiveness of the presented multilevel inverter has been validated by simulation results with PSCAD/EMTDC software.

Keywords:

Multilevel inverter , Cascaded H-bridge (CHB) , Switched series , Hybrid Modulation