High Gain PWM Method and Active Switched Boost Z-source Inverter With Less Voltage Stress on the Devices

Abstract

This article presents a new circuit topology for high voltage gain active switched boost quasi Z-source inverter (qZSI) and a pulsewidth modulation (PWM) technique. The higher boosting capability with a lower number of elements, the continuous source current, the less voltage stress across the devices, and having the common ground are the main advantages of the proposed structure. The voltage gain of the proposed inverter is twice that of the conventional capacitor-assisted qZSI (sCA-qZSI). Other benefits of the proposed inverter over the sCA-qZSI are the reduction of Z-source passive components and shoot-through current. Compared to the conventional active switched inductor boost qZSI, the proposed inverter has higher output voltage and also lower shoot-through current, while it has fewer components (one fewer inductor, two fewer diodes, but one more capacitor). The boost factor of the proposed inverter is more than twice that of the classic ones. Besides, a high gain PWM technique is proposed, which can be applied to any types of Z-source inverters. Both the simulation and experimental results of the proposed inverter under the proposed PWM technique are examined to validate their operation.