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This article presents a method for generating a family of transformerless inverters with common ground, for the connection of photovoltaic or battery energy storage systems with the electrical grid. Using the proposed method, four common-ground buck type inverter topologies are derived from bidirectional dc–dc converters based on buck–boost, SEPIC, zeta and boost–buck converters, which have in common the static gain given by ${D \mathord{/ {\vphantom {D {(1 - D)}}} } {(1 - D)}}$. The operation of each generated topology is explained and confirmed by computer simulation results. A comparative analysis between the four generated topologies and other transformerless common-ground inverters are included, considering the number of components, voltage ratings, output power, switching frequency, reported efficiency at rated power, and the requirement for filter insertion. Experimental results obtained in the laboratory, with tests performed on a nonoptimized experimental prototype are presented, for the topology based on the bidirectional zeta converter. [ABSTRACT FROM AUTHOR]

This paper proposes a modular isolated dc–dc converter, based on the input-series and output-series association of the full-bridge PWM dc–dc converter with capacitive filter. The main attribute of the proposed architecture is its ability to provide self-balance of the input and output voltages across the individual converters, without voltage loop control scheme, both in the steady-state and transient operations. Circuit operation, theoretical analysis, and modeling are included in this paper, along with experimental results taken from a laboratory prototype with four modules, 1600-Vdc total input voltage, 1600-Vdc total output voltage, 4-kW output power, and 40-kHz switching frequency. Possible applications include high-voltage power supplies, solid-state transformers, dc current distribution systems, and renewable electric energy systems. [ABSTRACT FROM PUBLISHER]

In this research, the study and implementation of the t-type parallel resonant dc–dc converter in high-voltage power supplies for travelling wave tube applications is presented. The proposed converter shares the benefits of the traditional full-bridge parallel resonant dc–dc converter, such as zero voltage switching on primary side switches over a wide load range, symmetric three-level voltage across the transformers primary winding, and integration of transformers leakage inductance and winding capacitance during its basic operation. However, only two switches are subjected to the input voltage, while the other two switches are subjected to half of the input voltage. Theoretical analysis, commutation analysis, and design guidelines are presented. The theoretical analysis validation and efficiency investigation are conducted through a t-type parallel resonant converter prototype, which operates with 1.5 kW and 97.12% efficiency. Hence, experimental results of a travelling wave tube power supply prototype operating with 1.5 kW of output power, 400 Vdc input, and four high output voltages, whose measurements results are Vo1=1382\,\rm {V}, Vo2=3505\,\rm {V}, Vo3= 1504\,\rm {V}, and Vo4=3338\,\rm {V}, confirm the feasibility of the proposed implementation. [ABSTRACT FROM PUBLISHER]