Implementation of Pulse Width Modulation Technique for Achieving Increased Voltage Gain and Balanced Voltage Stress in the A-Source Inverter

The Z-source converter was first introduced as a buck-boost dc-ac single-stage inverter in 2003. Different structures of impedance source inverters have been introduced for improving the performance of power inverters. Due to their specific structure, these inverters use shoot-through state in order to increase the output voltage. Therefore, in addition to improving the reliability of systems, they create a single-stage dc-ac inverter capable of reducing and increasing voltage at the same time. Recently, a three-winding network called the A-source network has been introduced. A new Pulse Width Modulation method has been proposed to improve the voltage gain and reduce switching losses. In this new method, duty cycle of the switch is controlled using the third harmonic injection and the new reference voltages in the three-phase A-source inverter. The proposed modulation method reduces the switching losses and increases voltage gain without adding any additional hardware to the inverter structure. In this method, the buck-boost single-stage structure of the inverter is maintained. In this paper, the proposed method is partially analyzed and compared to the conventional Pulse Width Modulation methods. In this method, the third harmonic injection is used to increase the modulation index to 1.15 and thereby reduce the switching losses. The simulation of the proposed and conventional methods and analyzes, demonstrated the ability of the proposed system.