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Summary: This study proposes a new design for a non‐isolated buck converter with continuous input current. As required, the integration of additional modules into the existing structure permits a significant decrease in the converter's gain to attain significantly lower values. In order to create the proposed converter, the input voltage connections to the Ćuk converter were changed. In this configuration, the operational state of the Ćuk converter has been changed from buck‐boost to step‐down by connecting the input power source's negative polarity to the inductor's terminal. In addition, the proposed converter benefits from a common ground between the input source and output port. Moreover, it can achieve a significant reduction in gain by increasing the number of series modules. Finally, the compact converter was smoothly incorporated onto a printed circuit board (PCB) and afterward validated by an output power of 80 watts. [ABSTRACT FROM AUTHOR]

This paper proposes a new isolated high step‐down dc‐dc converter with a more extensive output range and high efficiency. The interleaved output and ZVS‐ZCS switching for all semiconductors have made the converter appropriate for high output current applications. An auxiliary inductor is used to achieve the ZVS (zero‐voltage switching) and ZVZCS (zero‐voltage zero‐current switching) condition, which charges and discharges the parallel snubber capacitors of the power switches at different modes of operation. Therefore, the switching losses of semiconductor components are reduced significantly, which results in enhanced efficiency. Moreover, the connection of an auxiliary capacitor in series with the transformer has prevented the probability of DC‐current saturation. The proposed converter could be controlled with duty‐cycle or switching frequency variations. However, the output voltage control with the switching frequency variations gives an extended range of output voltage compared with the other presented converters. Moreover, a coupled inductor is used to relate the output gain with the turn ratios, which causes a more extensive range for output voltage gain. Finally, the theoretical analysis is given and is compared with a 140 W experimental prototype, which converts a higher input voltage 300v to 7.5 V of the output voltage. [ABSTRACT FROM AUTHOR]

In this paper, a new configuration of Marx generator with high‐voltage (HV) gain is presented for electroporation applications. Each module consists of one switch, one capacitor, and two diodes. The capacitors are charged in parallel with the input inductor and the input DC voltage source simultaneously; eventually, the charged capacitors are connected in series, and the HV output pulses are generated. The load is connected differently at the output stage, and there is not any switch at the output stage to generate the HV pulses. The majority of Marx generators suffer from the high number of modules to reach the desired pulse peak voltage. Due to the high‐voltage gain of the proposed topology, fewer modules are needed to achieve the desired HV pulse peak voltage. Mathematical analysis is presented along with a full design of the system components. Soft switching reduces the switching power loss in this converter, which is presented in detail. A comparative study is carried out to demonstrate the advantages of the proposed structure. Finally, simulation and experimental results are presented to validate the proposed concept. [ABSTRACT FROM AUTHOR]

A novel high-efficiency transformerless buck-boost DC-DC converter is proposed in this paper. The presented converter voltage gain is higher than that of the conventional boost, buck-boost, CUK, SEPIC and ZETA converters, and high voltage gain can be obtained with a suitable duty cycle. The voltage stress across the power switch is low. Hence, the low on-state resistance of the power switch can be selected to decrease conduction loss of the switch and improve efficiency. The input current ripple in the presented converter is low. The principle of operation and the mathematical analyses of the proposed converter are explained. The validity of the presented converter is verified by the simulation results in PSCAD/EMTDC software and experimental results based on the prototype circuit with 250 W and 40 kHz. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]