A Transformerless Boost-Modified Cuk Combined Single-Switch DC-DC Converter Topology with Enhanced Voltage Gain

: Recently, the research is towards the development of high static gain DC-DC converters suitable for renewable energy applications. The high voltage gain can be achieved using isolated and non-isolated configurations of the converter. The magnetically coupled inductor based isolated DC-DC converter structures can have improved voltage gain, but they need large size inductors which may lead to increased cost. Thus, the modified structures of non-isolated conventional boost, CUK, and SEPIC topologies with inclusion of additional controlled and uncontrolled switches along with large number of passive components are employed to achieve the improved voltage gain. However, it leads to increased complexity and control. Hence, the researchers concentrated on development of hybrid non-isolated DC-DC converter topologies capable of achieving enhanced static voltage gain, without adding extra controlled switches and passive elements. In this paper, a hybrid non-isolated single-switch DC-DC converter structure is proposed for achieving high voltage gain than that of traditional non-isolated topologies. The proposed hybrid structure operating in continuous inductor current mode is obtained by connecting the conventional boost and the modified CUK converters in parallel. The power switch and the diodes have low voltage-current stress. The operation of the proposed hybrid topology during various modes is explored. The mathematical modeling of the proposed converter is also provided. The MATLAB / SIMULINK study of the suggested hybrid converter has been implemented. The digital simulation study proves the feasibility of the proposed hybrid converter concept and its steady-state behavior.