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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. [ABSTRACT FROM AUTHOR]

In this article, a new structure of the switched-inductor/capacitor quasi Z-source inverter (SLC-qZSI) is proposed that has a high boost factor in a high modulation index to provide an improved quality output voltage. Additionally, this structure has features such as equal and low voltage stress on capacitors of SLC cells and diodes, identical current ripple for the source and all inductors, a low shoot-through (ST) current in the main switches, and a continuous input current with no startup inrush current. The performance of the proposed structure is confirmed using MATLAB/Simulink software, and the simulation results are validated by using a prototype of the proposed structure. [ABSTRACT FROM AUTHOR]

A new nonisolated, high step-up dc–dc converter is proposed based on the current-fed Cockcroft–Walton Voltage Multiplier (CW-VM) that can be used as the boosting power stage of converter for low-voltage low power renewable energy sources such as photovoltaic and fuel cells. The proposed converter employs two low-voltage common-emitter switches. Utilizing the current-fed CW-VM eliminates some problems associated with the conventional voltage-fed type such as voltage ripple and load-dependent voltage droop. Other advantages of the proposed converter are continuous input current, high voltage gain, and high efficiency. Steady state operation principles, specifications, and design considerations of the proposed converter are illustrated. Furthermore, efficiency analysis of the converter is performed and discussed. Experimental tests for a 200 W prototype are carried out which confirm the theoretical analysis. [ABSTRACT FROM AUTHOR]

In this paper, two structures are proposed for the switched-inductor quasi-Z-source inverter. In the proposed structures to extend the voltage gain of inverter, two new switched-inductor structures are used. In the proposed structures, voltage across the capacitors in the Z-source network and in the switched-inductor is symmetric and small. The other advantage of proposed inverters is known as achieving higher voltage gain per smaller duty cycle ratio (of shoot-through). Compared with a conventional continuous input current switched-inductor quasi-Z-source inverter at the same gain voltage, there is less of a ripple of input current in the proposed inverters. In this paper, at first the both the conventional and the proposed switched-inductor Z-source inventers are thoroughly investigated to find out their governing relations. Then, the proposed Z-source inverters are compared with the conventional ones by simulating them to assess their performance efficiency. Next, applying the simple boost pulse width modulation the simulation is carried out with PSCAD/EMTDC software. After that, to evaluate the obtained results, the prototypes of the proposed inverters with 48 Vdc input voltage are used. [ABSTRACT FROM PUBLISHER]