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In the present article, the boost factor of the Z-source inverter is noticeably increased by using the switched-inductor structure. The proposed inverter is based on the switched-inductor Z-source inverter which has two series diodes in its switched-inductor. In the proposed ZSI instead of these two series diodes, two capacitors are used. In comparison with the conventional structure, in the smaller duty cycle ratio the proposed structures generate higher voltage. Besides, in the second proposed structure to reduce the voltages on the capacitors of the Z-source network, a dc source is placed between the inverter bridge and the Z-source network. The dc source and the inverter have common ground in both the proposed structures. The conventional and proposed inverters are thoroughly investigated to find out their governing relations, then, the boost factor and voltage across capacitors in both proposed and conventional inverters are compared with each other by simulating them in PSCAD/EMTDC. Next, the prototypes of the proposed inverters with 25 V dc input voltage are used to evaluate the obtained results. [ABSTRACT FROM AUTHOR]

This paper proposes two nonlinear exact and simple state space models of a Zsource converter (ZSC) connected to an ac grid. A generic model of a ZSC accompanied with proper controllers are proposed and a dynamic model of the whole system is derived; as a result, based on a simple one, an equivalent block diagram of the current-controlled ZSC system is proposed. The ac small signal stability method is applied and the impact of controller parameters on network's stability is discussed. Besides, overall system dynamic performance has been assessed in the event of perturbations. Time-domain simulations have been implemented in PSCAD/EMTDC to validate the accuracy of the models and effectiveness of the proposed controllers. The results of the exact model are compared with the response of the equations which are applied in MATLAB. [ABSTRACT FROM AUTHOR]

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]