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This paper presents an improved switched‐inductor quasi‐Z‐source inverter with a higher boost factor than similar inverters, which integrates a switched‐capacitor and a three‐winding switched‐coupled inductor into a conventional quasi Z‐source inverter (q‐ZSI). The proposed inverter is called a switched‐capacitor trans quasi Z‐source inverter (SCT‐q‐ZSI). In this topology, the input current is continuous, and a high voltage gain is reachable with lowduty cycles (D). In this structure, capacitors are used instead of the side diodes of the switched‐inductor quasi Z‐source inverter. The proposed converter has a low inrush current at the startup which might damage the converter components. The performance of the proposed inverter is investigated at different operating modes and the voltage and current equations of all elements are calculated. The analysis, derivation of boost factor, capacitor voltages, and components, of the proposed inverter, are carried out and are compared with similar inverters. Finally, analytical, simulation, and experimental results are also presented to validate its advantages. [ABSTRACT FROM AUTHOR]

In this article, two high step-down bridgeless power factor correction rectifiers based on the switched inductor network (SIN) are introduced. The proposed rectifiers employ the SIN to provide high step-down voltage gain with a higher duty cycle than the competitors. They also offer higher efficiency, lower current stress, and total peak switching device powers. A thorough and straightforward design algorithm in the discontinuous conduction mode is provided that ensures a unity power factor and a low total harmonic distortion with a simple control scheme. As a demonstration of the superior performance of the proposed rectifiers, a 300-W high-gain sepic rectifier setup with 48Vdc output voltage from a 230Vrms/50Hz source is built in the laboratory. [ABSTRACT FROM AUTHOR]

Two structures are proposed based on the quasi Z‐source inverter (qZSI), which can significantly raise the output voltage in applications, including photovoltaic and fuel cells, in which the input voltage is low. The proposed inverters provide a continuous input current and reduce the voltage stress on capacitor. Besides, the proposed switched‐capacitor‐inductor qZSI (SCL‐qZSI) can suppress inrush current at the start up moment as this current might damage the devices. The performance of the proposed structures is investigated at different operating modes, and the voltage equations are calculated. The voltage stress on switches, the voltage stress on capacitors, the voltage stress on diodes, and the current stress on inductor, as well as the average DC‐link current, the gain voltage (G), and the boost factor (B) of the proposed inverters, are analysed and derived. They are then compared with similar converters. To confirm the performance of the proposed converters, a laboratory sample of converters is made, which with output voltages, capacitors voltages, input and output current for the proposed converters. The DC‐link (Vi) voltage is 95 with boost factor 1.6 for SCL‐qZSI, and the DC‐link voltage is 216 with boost factor 3.6 for the enhance switched‐capacitor‐inductor qZSI (ESCL‐qZSI), which confirms the relationships obtained from the proposed converters. Also, the abbreviation for this paper is shown in table 1. [ABSTRACT FROM AUTHOR]

The Z‐source inverter was introduced to overcome shortcomings of voltage source inverter and current source inverter. In this paper, the concept of one switched‐inductor Z‐source inverter is extended to switched‐capacitor inductor ZSI with an impedance network. In the proposed inverter, capacitors are used instead of the side diodes of the one switched inductor Z‐source inverter. The proposed inverter has a higher boost factor compared to One SL‐ZSI and quasi‐ZSI. Also, it has lower voltage stress compared to similar inverters. The proposed inverter can be extended to n cases in cascade form. The components used in the proposed topology are lower than the SL‐ZSI. The analysis, derivation of boost factor, capacitor voltages, diode voltages, and switch voltages stress of the proposed inverter topology are carried out and are compared with the similar inverters. The advantages of the proposed structure are verified through simulation and implementation. The simulation is performed in MATLAB/SIMULINK. [ABSTRACT FROM AUTHOR]

Two new power factor correction (PFC) rectifiers with the voltage buck-boost capability are proposed in this article, called as Ferdowsi rectifiers (FRs). The proposed rectifiers employ a reduced number of semiconductors compared to the competitors. Also, since the reverse recovery problem of antiparallel diodes of transistor switches is avoided, then MOSFETs can be readily utilized, which lets much higher switching frequencies and lower size of passive components. In addition, two parallel capacitors provide a path for the input current during the discharge mode of the buck-boost inductors to improve the current quality. The discontinuous conduction mode operation of the proposed rectifiers guarantees a high quality input current with a low total harmonic distortion. All aforementioned features offer a highly efficient operation and at the same time a purely sinusoidal current drawn from the ac source compared to the previous well-developed competitors. The validation of the theoretical achievements is performed by extensive tests on a laboratory test rig. [ABSTRACT FROM AUTHOR]

This paper introduces a novel single-phase buck–boost noninverting variable-frequency ac–ac converter that offers higher efficiency compared to the competitors. This converter utilizes a lower number of semiconductors. A simple and flexible switching strategy is also proposed, which generates the desired output waveform avoiding unnecessary high-frequency switching operation of semiconductor devices. A high reliable operation due to the elimination of the input source shoot-through risk, an inherent commutation capability that mitigates the voltage spikes across the semiconductors, a lower semiconductors rating requirement, an improved input current waveform quality, and a smaller required input filter inductor are the main advantages of the proposed converter. Thus, the proposed converter can be successfully applied to many industrial applications such as medium-frequency transformer isolation for traction and wind turbine converters, ac–dc high-voltage conversion based on Cockcroft–Walton circuit and induction heating systems. The theoretical achievements and claims are all confirmed through extensive experimental tests on a 200-W laboratory setup. [ABSTRACT FROM AUTHOR]